91: Nail Disorders Flashcards
(209 cards)
1
Q
What is Anonychia and what are its potential causes?
A
Anonychia is characterized by a complete or almost complete lack of the nail. It is usually inborn and may be a genetic trait or the result of drug or toxin-induced lack of nail formation during embryogenesis.
2
Q
What is Cooks Syndrome and how does it relate to Anonychia?
A
Cooks Syndrome, also known as Atelephalangia with anonychia, is a condition where there is no terminal phalanx and no nail growth.
3
Q
What are the characteristics of Racket Nail?
A
Racket Nail is characterized by a short wide nail, mostly of the thumb, that develops after the age of 12 years. It involves premature ossification of the epiphysis of the distal phalanx and is autosomal dominant with variable expression and penetrance.
4
Q
What is Brachyonychia and in which patients may it develop?
A
Brachyonychia refers to very short nails and may develop in patients under chronic hemodialysis who develop tertiary hyperparathyroidism with resorption of the bone of the terminal phalanx.
5
Q
What is Leukonychia and what are its common causes?
A
Leukonychia is the most common color change of nails, caused by alterations in the keratinization of the nail plate. It can be due to parakeratosis or eosinophilic cytoplasm in histologic sections, and may appear as small patches or transverse bands in children and youngsters.
6
Q
What are the differences between Total diffuse leukonychia and Subtotal diffuse leukonychia?
A
Total diffuse leukonychia is usually inborn, while Subtotal diffuse leukonychia is sometimes seen in chronic liver disease. Both conditions involve changes in the appearance of the nails.
7
Q
What is Pseudoleukonychia and what causes it?
A
Pseudoleukonychia is characterized by a white surface of the nail, which is infected by fungi. It is also referred to as (pseudo) leukonychia trichophytica, although nondermatophyte molds may also be causative.
8
Q
A patient with chronic liver disease presents with subtotal diffuse leukonychia. What is the likely cause of this nail change?
A
Subtotal diffuse leukonychia in this case is likely due to chronic liver disease.
9
Q
What are the characteristics and potential causes of Erythronychia (red nails)?
A
- May appear as red spots in the matrix.
- Can present as one or more longitudinal streaks in the distal matrix and nail bed.
- Lichen planus is associated with multiple red bands.
- Onychopapilloma or Bowen disease presents as a single red band, indicating a biopsy is needed.
- Darier disease shows alternating narrow white and red bands.
10
Q
What is Chloronychia and how is it treated?
A
- Chloronychia (green nails) is often caused by colonization of the nail by Pseudomonas aeruginosa.
- Symptoms include:
- Circumscribed swelling and detachment of the proximal nailfold.
- Lack of the cuticle.
- Lateral onycholysis.
- Treatment options include:
- Soaking in diluted white vinegar, 2-3 times daily for 10 minutes, then brushing fingers dry.
- Household bleach for fingertip baths (undiluted or 1:1 diluted in water).
- Topical antibiotics like gentamycin (less effective).
- Systemic antibiotics do NOT reach the site of infection.
- In rare cases, systemic treatment with ciprofloxacin may be indicated.
11
Q
What does the presence of blue nails indicate?
A
- Blue nails can indicate swimming in water with copper sulfate as a disinfective agent.
12
Q
What are the causes and characteristics of Melanonychia (brown to black nails)?
A
- Melanonychia is associated with melanin pigmentation of the nail.
- Causes include:
- Potassium permanganate and tobacco smoke leading to brown nails.
- Silver nitrate causing jet-black nails.
- Bacteria causing dirty grayish discoloration.
- It may be diffuse and total, transverse, or longitudinal.
- A brown to black band may develop in the nail from the proximal nailfold into the free margin of the nail plate, caused by:
- Melanocyte activation.
- Lentigo.
- Nevus.
- Melanoma of the matrix.
- Multiple melanonychias can occur in several or all digits, common in dark-skinned individuals and Asians, and is a physiologic phenomenon in almost all African Americans.
- Conditions that may exhibit melanonychia include:
- Pregnancy.
- Drugs.
- Vitamin B12 deficiency.
- Addison disease.
- HIV infection.
- Ungual lichen planus.
- Bowen disease of the nail (associated with HPV Type 56).
13
Q
A patient has a single longitudinal red band on the nail. What are the possible diagnoses, and what diagnostic step is recommended?
A
Possible diagnoses include onychopapilloma or Bowen disease. A biopsy is recommended to confirm the diagnosis.
14
Q
A patient presents with a bluish nail matrix and a history of exposure to silver nitrate. What is the diagnosis?
A
The diagnosis is argyria, characterized by a slate gray to bluish nail matrix due to silver nitrate exposure.
15
Q
What is the significance of longitudinal nail pigmentation in adults?
A
Longitudinal nail pigmentation is the most frequent sign of nail melanoma. Single-digit melanonychia in an adult requires a biopsy for further evaluation.
16
Q
What are the characteristics of subungual hematoma?
A
Subungual hematoma is characterized by:
- Single, heavy trauma or repeated microtraumas, often from ill-fitting shoes.
- Prussian blue-negative or Perls stain-negative.
- It takes months to grow out but does not reach the free margin of the nail plate.
- Dermatoscopy shows round red to dark-brown globules.
- Hematomas occupying more than 50% of the nail field are commonly associated with a fracture of the distal phalanx.
17
Q
What conditions are associated with splinter hemorrhages?
A
Splinter hemorrhages are narrow red to almost black longitudinal lines in the distal nail bed and can be caused by:
- Trauma
- Psoriasis
- Scleroderma
- SLE (Systemic Lupus Erythematosus)
- RA (Rheumatoid Arthritis)
- Antiphospholipid syndrome
- Hematologic malignancies
- Bacterial endocarditis with subsepsis lenta, which may occur with Osler nodes, Janeway lesions, and retinal hemorrhages called Roth spots.
Oblique splinter hemorrhages may also be a sign of trichinosis.
18
Q
A patient with a history of trauma presents with a subungual hematoma. What is a key distinguishing feature from melanonychia?
A
A subungual hematoma never reaches the free margin of the nail plate, unlike melanonychia.
19
Q
What is onycholysis and what are its common causes?
A
Onycholysis is the detachment of the nail from the distal nail bed. Common causes include:
- Psoriasis
- Lichen Planus (LP)
- Atopic Dermatitis (AD)
- Pityriasis Rubra Pilaris (PRP)
- Onychomycoses
- Tumors of the nail bed
20
Q
What is the treatment for onycholysis?
A
The treatment for onycholysis includes:
1. Avoiding moisture
2. Cutting the nail back to the adherent part
3. Brushing the nail bed twice daily with a disinfective solution
4. Applying an antimicrobial cream
Approximately one-half of the regrowing nail will remain attached to the nail bed, but it remains susceptible to recurrence of onycholysis.
21
Q
What characterizes subungual hyperkeratosis and its common causes?
A
Subungual hyperkeratosis is characterized by its association with onychomycoses and psoriasis. Common causes include:
- Trauma
- Allergic and toxic contact dermatitis
- Atopic dermatitis
It is virtually always associated with onycholysis, except in pachyonychia congenita, where the nail covers an excessive nail bed hyperkeratosis in a horseshoelike fashion.
22
Q
What is onychogryposis and how is it treated?
A
Onychogryposis is characterized by:
- Exaggeration of nail bed and matrix hyperkeratosis
- Innumerable stacks of keratin layers piled up, growing upward, opaque, and often shaped like a ram’s horn
- No contact with the nail bed anymore
- Extremely short nail pocket
- Commonly seen in elderly, neglected, and debilitated individuals.
Treatment involves nail avulsion, often completed by nail matrix cauterization to prevent regrowth of a grypotic nail.
23
Q
What is pterygium and in which conditions is it commonly seen?
A
Pterygium is characterized by:
- Bridging of the nail pocket by connective tissue, often due to scars
- Very common in lichen planus
- Occasionally seen in other conditions such as:
- Bullous pemphigoid
- Trauma
It may divide the nail into two parts and can lead to complete nail destruction if it occupies almost the entire nail pocket.
24
Q
What is pterygium inversum and what are its implications?
A
Pterygium inversum occurs when:
- The nail plate does not separate correctly from the nail plate at the hyponychium and remains attached.
- This results in painful hyperkeratosis that obliterates the distal groove.
It is common in conditions like acral scleroderma and Raynaud syndrome, but may also be idiopathic. Nail trimming can be very difficult and painful.
25
What are Beau Lines and how do they manifest on nails?
Beau Lines are temporary slowdowns or arrests in nail formation, resulting in transverse grooves that run parallel to the lunula border. They can be shallow (lateral) or deeper (centrally).
26
What is Onychomadesis and what are its potential consequences?
Onychomadesis is a longer-lasting arrest of nail matrix proliferation that can lead to a proximal gap in the nail and proximal onycholysis, potentially resulting in loss of the nail.
27
What factors can lead to the development of Beau Lines and Onychomadesis?
Factors include acute severe diseases, high fever, certain drugs (retinoids), zinc deficiency, autoimmune bullous diseases, and trauma. Localized cases can occur after conditions like hand-foot-and-mouth disease.
28
What are the characteristics of Pits in nails?
Pits are small depressions in the nail surface caused by abnormal keratinization in the apical matrix, producing small mounds of parakeratosis. They can be associated with conditions like Nail Psoriasis, Alopecia areata, and atopic dermatitis.
29
What is Trachyonychia and what are its associated features?
Trachyonychia is characterized by rough nails, multiple pits, longitudinal striations, and ridges. It can be associated with conditions like ungual lichen planus and may present as 20-nail syndrome if many nails are affected.
30
What causes longitudinal grooves in nails?
Longitudinal grooves can result from pressure on the nail matrix or from a small tumor in the proximal nailfold.
31
What is Onychorrhexis and what causes it?
**Onychorrhexis** is characterized by multiple longitudinal fissures, often associated with nail thinning and ridges. It is caused by **defective keratinisation**.
32
What are the common causes of Onychoschizia?
**Onychoschizia** involves lamellar splitting of the nail at its free end, usually confined to fingernails. Common causes include:
- Frequent water contact leading to hydration and dehydration of the nail
- Dermatoses
- Onychomycosis
- Peripheral neuropathies and vascular disease
- Occupational traumas
- Various drugs that interfere with nail growth
- The role of nutrition is frequently overestimated.
33
What are the general disorders that affect brittle nails?
General disorders that affect brittle nails include:
- **Chronic anemia**
- **Iron deficiency**
- **Zinc deficiency**
- **Vitamin deficiencies** (A, B6, C)
- **Hypervitaminosis A**
- **Genetic diseases** affecting keratin formation
- Local damage from trauma, alkalis, detergents, and overzealous manicures.
34
What is the most common type of ingrown nail and what factors contribute to it?
The most common type of ingrown nail is **distal-lateral ingrowing of the edge of the big toenail**. Contributing factors include:
- Discrepancy between too wide a nail plate and too narrow a nail bed
- Tight socks
- Hyperhidrosis
- Overcurvature of the nails.
35
What are the treatment options for ingrown nails?
Treatment options for ingrown nails include:
1. Conservative treatment with insertion of a wisp of cotton between the offending nail and the nail sulcus, taping to pull the soft tissue away from the nail.
2. Protection of the soft tissue from the nail margin by a gutter, requiring local anesthesia.
3. Surgery to narrow the nail or to remove the swollen soft tissue.
36
A patient with brittle nails has lamellar splitting at the free end. What is the likely diagnosis, and what are common causes?
The diagnosis is onychoschizia, commonly caused by frequent water contact, dermatoses, or nutritional deficiencies.
37
What is the primary cause of retronychia?
Retronychia is primarily caused by a single strong or repeated minor trauma to the nail, leading to a backward movement of the nail plate.
38
What are the two types of pincer nails?
The two types of pincer nails are:
1. **Acquired** - resulting from foot deformation, degenerative distal interphalangeal osteoarthritis, and some dermatoses.
2. **Hereditary** - characterized by symmetrical involvement of the big toenails and often some, but rarely all, lesser toenails.
39
What is the treatment of choice for retronychia?
The treatment of choice for retronychia is **nail avulsion**.
40
What are the effects of using nail hardeners?
Nail hardeners frequently prescribed for brittle nails contain **formaldehyde**, which renders the nails harder but decreases their elasticity.
41
What complications can arise from overzealous manicures?
Overzealous manicures can lead to several complications, including:
- Onycholysis semilunaris
- Wavy nail surface
- Loss of the cuticle with penetration of foreign substances under the proximal nailfold, leading to paronychia
- Bacterial colonization and infection.
42
What is a common treatment for infected nails?
A common treatment for infected nails includes using **urea in high concentrations** to soften mycotic nails, with a 40% urea paste applied under occlusion for 3 to 5 days to make the infected nail portions soft enough to scrape off.
43
A patient presents with a proximal ingrowing nail and granulation tissue emerging from under the nailfold. What is the likely diagnosis and treatment?
The likely diagnosis is retronychia, caused by trauma leading to backward movement of the nail plate. The treatment of choice is nail avulsion.
44
What is the likely diagnosis and treatment for a patient with a proximal ingrowing nail and granulation tissue emerging from under the nailfold?
The likely diagnosis is retronychia, caused by trauma leading to backward movement of the nail plate. The treatment of choice is nail avulsion.
45
What are the two types of pincer nails and how are they differentiated?
The condition is pincer nails. It can be acquired (due to foot deformation or osteoarthritis) or hereditary (symmetrical involvement of big toenails).
46
What are the most common nail changes associated with psoriasis?
The most common nail changes associated with psoriasis include:
- **Pits**: Small, sharply delimited depressions in the nail surface.
- **Subungual hyperkeratosis**: Thickening of the skin under the nail.
- **Onycholysis**: Separation of the nail from the nail bed.
- **Salmon spots**: Yellowish-brownish spots with a red margin.
- **Red lunulae**: Red discoloration of the lunula.
- **Splinter hemorrhages**: Reddish-brown streaks under the nail.
- **Leukonychia**: White discoloration of the nail plate.
- **Psoriatic paronychia**: Inflammation of the skin around the nail.
47
What is the clinical significance of pits in psoriatic nails?
Pits in psoriatic nails are clinically significant because:
- They are the **most frequent** nail change in psoriasis.
- The presence of **≥10 pits/nail or >50 pits on all nails** is considered proof of nail psoriasis.
- Pits arise from tiny psoriatic lesions in the apical matrix leading to parakeratosis, which can indicate the severity of the condition.
48
How is nail psoriasis diagnosed?
Nail psoriasis is diagnosed based on:
- **Clinical grounds**: Observation of nail changes.
- Presence of **skin lesions** elsewhere on the body along with at least one psoriatic nail feature.
- **HPx** (histopathological examination) is usually pathognomonic for psoriasis.
- Additional lab examinations may be required for conditions like Reiter disease.
49
What are the treatment options for nail psoriasis?
Treatment options for nail psoriasis include:
- **Topical treatments**: Often resistant; penetration of the drug to the diseased tissue is a challenge.
- **Combination therapy**: A 3-month trial of a vitamin D3 derivative plus a potent corticosteroid is recommended.
- **Injections**: Triamcinolone acetonide injections into the proximal nailfold can improve symptoms but may be painful.
- **Systemic therapies**: Such as biologics, are considered the best treatment results for nail psoriasis.
50
What is the relationship between psoriatic nails and onychomycosis?
The relationship between psoriatic nails and onychomycosis includes:
- Onychomycosis is the most important association with psoriatic nails.
- Both conditions may appear similar, but psoriatic nails can be colonized by pathogenic fungi.
- True infections of the psoriatic nail are not infrequent, complicating the clinical picture.
51
What is the underlying mechanism of nail changes in a patient with psoriatic arthritis?
The changes are due to inflammation at the insertion points of tendons and ligaments, leading to enthesitis and aberrant innate immune responses.
52
What is the pathophysiology behind splinter hemorrhages and salmon spots in a patient with psoriasis?
Splinter hemorrhages result from damage to dilated capillaries in the nail bed, while salmon spots represent psoriatic plaques in the distal matrix and nail bed.
53
What causes deep, regular pits on the nail surface in a patient with nail psoriasis?
The pits are caused by tiny psoriatic lesions in the apical matrix, leading to parakeratosis that breaks off.
54
What are yellowish-brown spots with a red margin under the nail plate called in nail psoriasis?
These spots are called salmon spots, representing psoriatic plaques in the distal matrix and nail bed.
55
What is the analogous skin phenomenon to splinter hemorrhages in nail psoriasis?
The analogous skin phenomenon is the Auspitz sign, caused by damage to dilated capillaries.
56
What are the distinguishing features of psoriatic hyperkeratosis?
Psoriatic hyperkeratosis may be marked and extreme, resembling **pachyonychia congenita**. It involves both the dorsal and ventral surfaces of the proximal nailfold, causing thickening and rounding of the free edge, and is associated with loss of the cuticle, leading to **chronic paronychia**.
57
What are the characteristics of psoriatic arthritis related to nail involvement?
Psoriatic arthritis with severe nail involvement can lead to:
1. **Psoriatic paronychia**
2. **Complete nail destruction**
3. **Swelling of the DIP joint**
58
How does palmar plantar pustular psoriasis of Barber-Königsbeck present in terms of nail changes?
Palmar plantar pustular psoriasis of Barber-Königsbeck presents with:
- All nail changes described above
- **Elkonyxis**
- **Subungual yellow spots** representing large Munro abscesses
59
What is the significance of the mutation in the IL-36 receptor antagonist gene in generalized pustular psoriasis?
The mutation in the **IL-36 receptor antagonist gene** supports the assumption that generalized pustular psoriasis and acrodermatitis continua suppurativa belong to the group of **autoinflammatory diseases**.
60
What are the clinical features of Reiter disease in relation to nail changes?
Reiter disease (reactive arthritis) is characterized by:
- Joint, mucosal, eye, genitourinary, skin, and nail changes
- Nail changes are very similar to pustular psoriasis but may have a more **brownish tint** due to **RBC contents** in the pustules
- HPx shows **spongiform pustules**
61
What condition can mimic subungual hyperkeratosis without the oil-drop phenomenon in a patient with nail psoriasis?
Onychomycosis can mimic subungual hyperkeratosis without the oil-drop phenomenon.
62
What are the common clinical features of Acute Allergic Contact Dermatitis (ACD) related to nails?
- Redness of periungual skin with tiny vesicles that break and ooze, forming serous crusts.
- Secondary infection with pyogenic micrococci can lead to impetiginization.
- Desquamation develops, followed by cracking of volar aspects and transition to the hypoychium and lateral nailfolds.
- Nails may become grossly deformed with deep asymmetric transverse furrows and ridges.
- Matrix and nail bed involvement is rare but can be painful, leading to hyperkeratotic nail bed.
63
What is the treatment approach for chronic paronychia associated with eczema?
- Topical steroids for periungual eczematous lesions.
- Systemic treatment for very severe and painful lesions.
- Beveled excision of the thickened part of the proximal nailfold for recalcitrant paronychia.
64
How does Nummular eczema present in the nail region?
- Mainly involves the proximal nailfold.
- Characterized by round red infiltrated plaques exhibiting tiny papules covered with small serosanguinolent crust.
65
What are the distinguishing features of Atopic dermatitis in relation to nails?
- Shiny nails.
- Chronic itchy dermatitis in children and young to middle-aged adults.
- Scratching with the free margin of the nails to relieve itch, often by rubbing with the back of the distal phalanx.
- Emollients may enhance the polishing action of this habit.
66
What is the prognosis for Twenty-nail dystrophy associated with eczema?
- Twenty-nail dystrophy usually disappears spontaneously by around 16 years of age.
67
What specific type of eczema is likely responsible for shiny nails and desquamation of the fingertips?
The likely type is atopic dermatitis, which can cause shiny nails and desquamation of the fingertips.
68
What is the likely diagnosis for chronic eczema with redness, scaling, and fissures around the nails?
The diagnosis is chronic irritant contact dermatitis, which is indistinguishable from chronic allergic contact dermatitis.
69
What is the likely diagnosis for a patient with a history of acrylic nail use and painful matrix and nail bed dermatitis?
The likely diagnosis is acrylate allergy, a form of allergic contact dermatitis.
70
What rare condition should be considered for a patient with chronic eczema and vesiculopustular lesions of the hyponychium?
The condition is parakeratosis pustulosa, which mainly occurs in young girls.
71
What specific condition is indicated by shiny nails and painful cracks in the lateral nail groove in a patient with chronic eczema?
The condition is atopic pulpitis sicca, often seen in atopic winter feet.
72
What is the likely diagnosis for round red infiltrated plaques on the proximal nailfold in a patient with chronic eczema?
The likely diagnosis is nummular eczema of the nail region.
73
What is the prevalence range of nail involvement in Alopecia Areata (AA)?
The prevalence of nail involvement in Alopecia Areata ranges from **10% to 65%**.
74
What are the two types of nail alterations observed in Alopecia Areata?
The two types of nail alterations in Alopecia Areata are:
1. **Rough nails** that lost their shine
2. **Pitted nails** with surface shine
75
What is the clinical significance of Koilonychia in Alopecia Areata?
**Koilonychia** is a sign of very severe nail involvement in Alopecia Areata, indicating significant pathology.
76
What are some common associations with Alopecia Areata?
Common associations with Alopecia Areata include:
- **Asthma**
- **Allergic rhinitis**
- **Atopic dermatitis (AD)**
- **Thyroid disease**
- **Thyroiditis**
- **Vitiligo**
77
What treatments are commonly used for nail changes in severe Alopecia Areata?
Common treatments for nail changes in severe Alopecia Areata include:
- **Tofacitinib**: A Jak inhibitor effective for hair loss and nail changes.
- **Topical treatments**: Steroids or steroid-calcipotriol combinations, though often ineffective.
- **Injections of triamcinolone acetonide**: Administered every 4 to 6 weeks, but can be cumbersome and painful.
78
What condition should be considered for a child with rough nails and longitudinal ridging?
The condition is trachyonychia, often associated with 20-nail dystrophy. Its hallmark is rough nails with longitudinal ridging.
79
What is the pathogenesis of rough, sandpapered nails in a patient with alopecia areata?
The nail changes are due to autoimmune-mediated damage by CD8+ lymphocytes expressing natural killer group 2 member D.
80
What is the histopathological pattern of nail involvement in a patient with alopecia areata who has brittle nails with serum inclusions?
Histopathology shows spongiotic dermatitis with lymphocyte exocytosis involving the matrix.
81
What are the common clinical features of Lichen Planus of the nails?
- Chronic disease
- Occurs with typical skin lesions
- Proximal nailfold involvement: bluish-red discoloration, sometimes associated with swelling
- Longstanding nail LP: nail thinning and obliteration of the nail pocket with pterygium formation; nail edge may look frayed.
- Apical matrix: site of the nail stem cells leading to scarring with permanent nail dystrophy.
82
What is the recommended treatment for Lichen Planus of the nails?
- Combination of a steroid + calcipotriol (recommended)
- Perimatricial injections of triamcinolone acetonide every 4 to 8 weeks, may be continued by IM injections, 0.5 to 1 mg/kg (50% recurrence)
- Biologics for recalcitrant cases.
83
What are the common clinical features of Autoimmune Bullous Disease affecting the nails?
- Chronic paronychia with oozing and crust formation (most common initial signs)
- Onychomadesis
- Sometimes loss of the nail
- Large clear periungual blisters, erosions with crusting and superficial impetiginisation.
84
What diagnostic methods are used for Autoimmune Bullous Disease?
- Suspected in case of longstanding oozing and crusting paronychia with onychomadesis and nail loss
- ELISA, Indirect IF, biopsy are necessary to make the diagnosis.
85
What is the prognosis for nail lesions in Autoimmune Bullous Disease?
- Nail lesions take between 6 and 18 months to grow out
- Pterygium is permanent.
86
What is the most common site of involvement in lichen planus of the nails?
The most common site of involvement in lichen planus of the nails is the proximal matrix.
87
What autoimmune condition should be suspected in a patient with chronic paronychia and oozing crusts?
Autoimmune bullous disease should be suspected. Diagnostic tests include ELISA, indirect immunofluorescence, and biopsy.
88
What histopathological findings confirm the diagnosis of lichen planus of the nails?
Histopathology shows a dense lymphocytic infiltrate around the apical matrix, leading to basal cell degeneration and impaired nail substance formation.
89
What is the most common initial sign in a patient with autoimmune bullous disease and nail loss?
The most common initial sign is chronic paronychia with oozing and crust formation.
90
What does pterygium formation indicate about the disease stage in lichen planus of the nails?
Pterygium formation indicates longstanding disease with scarring and permanent nail dystrophy.
91
What specific condition is indicated by large periungual blisters in a patient with autoimmune bullous disease?
The condition is bullous pemphigoid, and the prognosis depends on the control of cutaneous and mucous membrane lesions.
92
What are the clinical features associated with alterations of the nailfold capillaries in connective tissue diseases?
- Reduced, dilated, tortuous, shorter capillaries
- Aneurysms and bleeding, easily seen using a fluorescent dye showing vessel leakage.
93
What are the nonspecific signs associated with connective tissue diseases affecting the nails?
- Onycholysis
- Pterygium
- Clubbing.
94
How is the diagnosis of nail changes in connective tissue diseases typically made?
Diagnosis is usually made by evaluating skin lesions and through immunoserological tests.
95
What are the clinical features associated with alterations of the nailfold capillaries in connective tissue diseases?
Reduced, dilated, tortuous, shorter capillaries; aneurysms and bleeding, easily seen using a fluorescent dye showing vessel leakage.
96
What are the nonspecific signs associated with connective tissue diseases affecting the nails?
Onycholysis, pterygium, clubbing.
97
How is the diagnosis of nail changes in connective tissue diseases typically made?
Diagnosis is usually made by evaluating skin lesions and through immunoserological tests. Dermatoscopy and laser scanning confocal microscopy can also be used to observe capillary blood flow.
98
What are the common nail changes associated with Lupus Erythematosus (LE)?
Acute LE: Periungual erythema and red lunula; Chronic DLE: Red streaks in the nail bed, ridging of the nail, dystrophy, and white bands in diffusely brown nails of black patients.
99
What is the clinical significance of Scleroderma in relation to nail changes?
Scleroderma (acral variant) is characterized by ulceration of the pulp and narrowing of the tip of the finger ('parrot beak'), with the nail bending volarly, dull surface, pronounced ridging, and often nontransparent nail plate.
100
What is the prognosis for nail alterations in connective tissue diseases compared to skin lesions?
The clinical course, prognosis, and management for nail alterations are similar to those of skin lesions; however, nail alterations usually take longer to respond.
101
A patient with systemic lupus erythematosus (SLE) has periungual erythema and red lunulae. What is the underlying cause of these nail changes?
The nail changes are due to infarctions of the nailfold capillaries, leading to necrosis and scars.
102
A patient with systemic sclerosis has dull, ridged nails and narrowing of the fingertip. What is the term for this nail alteration?
The term is 'parrot beak' nails, seen in scleroderma with vascular damage.
103
A patient with systemic lupus erythematosus has red streaks in the nail bed. What chronic condition is associated with this finding?
The finding is associated with chronic discoid lupus erythematosus (DLE).
104
A patient with systemic lupus erythematosus has periungual erythema and red lunulae. What diagnostic tools can confirm vascular involvement?
Dermatoscopy and laser scanning confocal microscopy can confirm vascular involvement.
105
A patient with systemic lupus erythematosus has violaceous-blue discoloration of the nail unit. What specific condition is this?
The condition is chilblain lupus, associated with pernio-like changes.
106
What are the clinical features of leukocytoclastic vasculitis affecting the nail unit?
Leukocytoclastic vasculitis may affect the distal phalanx with the nail unit, particularly of the toes. It presents as dark red small palpable spots on the proximal nailfold and the pulp, which can lead to small necroses and painful dark red spots under the nail.
107
What is the significance of livedoid vasculopathy in relation to nail disorders?
Livedoid vasculopathy is a disorder that causes painful torpid ulcers, often referred to as atrophie blanche when located in the ankle region. It may affect the free margin of the proximal nailfold of toes, exhibiting lichenoid papules with reddening and white lines, and is associated with hypercoagulability and stasis.
108
What are the common infectious nail diseases and their characteristics?
Common infectious nail diseases include:
- Digital herpes simplex: Often disproportionately painful, presenting as small vesicles.
- Subungual warts: Very painful due to pressure on the bone, mimicking chronic paronychia.
- HFMD: Small oval blisters around the nail, possibly causing late onychomadesis.
- Bullous impetigo: Blisters with a stable roof that may extend around the nail.
- Whitlows (felons): Deep bacterial infections reaching the bone, causing pain and requiring surgery.
- Fungal nail infections: Extremely common, with clinical types that look similar; cultural identification is needed.
109
What are the clinical features and management of herpes simplex infections affecting the nail?
Herpes simplex infections present with small vesicles that develop clear content initially, which becomes yellowish over time. A visible red streak may extend from the finger to the arm, associated with lymphangitis and pain. Management includes:
1. Diagnosis via Tzanck smear, immunohistochemistry, or PCR.
2. Treatment of acute paronychia and bullous impetigo if present.
3. Monitoring for recurrent episodes, which may occur in waves and can lead to a herpes-free period after several months.
110
A patient presents with dark red small palpable spots on the proximal nailfold and pulp, which are painful and leave tiny scars. What is the likely diagnosis and its etiology?
The likely diagnosis is leukocytoclastic vasculitis. The etiology involves hypercoagulability and stasis, or microbial thrombi in infectious vasculitides.
111
A child presents with small oval blisters around the nail and late onychomadesis. What is the likely diagnosis and causative agent?
The likely diagnosis is Hand-Foot-Mouth Disease (HFMD), caused by Enterovirus Type 71 and Coxsackie virus A5, A16, or rarely B.
112
What are the clinical implications of onychomadesis in children after chickenpox?
Onychomadesis was observed in children several weeks after chickenpox, likely due to unnoticed viral blisters of the matrix. Treatment follows the general rules of HHV3 therapy.
113
What is the most common cause for viral warts of the nail unit?
HPV types 1, 2, 3, 4, and 7 are the most common causes for viral warts of the nail unit.
114
What are the characteristics of Enterovirus lesions on the nails?
Enterovirus lesions are intraoral aphthoid lesions that cause discomfort, with small vesicles on the palms, soles, and around the nail. They are oval in shape, with a gray blister roof and a narrow red margin, and may lead to onychomadesis of single nails after approximately 6 weeks.
115
What is the prognosis for Enterovirus infections?
The clinical course of Enterovirus infections is self-limited, with vesicles usually disappearing within 7 to 10 days. The prognosis is good, and there is no specific antiviral therapy required.
116
What treatment options are available for HPV-related warts?
Treatment options for HPV-related warts include aggressive keratolysis with salicylic acid, salicylic acid plus cryotherapy, laser treatments (ablative with CO2 or nonablative), daily treatment with Imiquimod, and Cidofovir as a third-line option.
117
What is the most characteristic bacterial infection associated with coccal infections around the nail?
A bullous impetigo that runs around the proximal part of the nail, commonly referred to as 'runaround'.
118
What are the common symptoms of a subungual whitlow?
It starts with a clear blister of the proximal and lateral nailfold that becomes putrid and often hemorrhagic, and is commonly painful.
119
What is the primary causative agent of coccal infections?
Most commonly caused by Staphylococcus; rarely by Streptococcus.
120
What is the characteristic color of the nail in Pseudomonas infections?
A green to brownish-black color, often associated with localized marginal paronychia.
121
What is the significance of the bacterial biofilm in Pseudomonas infections?
The bacterial biofilm is approximately 1000 times less sensitive to antibiotics than isolated bacteria of the same species.
122
What is the recommended treatment for Pseudomonas nail infections?
Baths with diluted white vinegar 2 or 3 times a day for 5 to 10 minutes, along with topical antibiotics like gentamycin if needed.
123
What is the prognosis for immunocompetent patients with Pseudomonas infections?
The prognosis is very good for immunocompetent patients.
124
What are the common complications associated with Digital herpes simplex infections?
It is more painful, develops lymphangitis, and starts with small clear blisters that coalesce and later become putrid.
125
A patient has a greenish discoloration of the nail with localized marginal paronychia. What is the causative organism and first-line treatment?
The causative organism is Pseudomonas aeruginosa. First-line treatment includes baths with diluted white vinegar 2-3 times a day and topical antibiotics like gentamycin.
126
A patient presents with a painful subungual whitlow. What is the most common causative organism and why is early treatment critical in children?
The most common causative organism is Staphylococcus. Early treatment is critical in children because the matrix may be permanently damaged within 24-48 hours.
127
What are the clinical features of onychomycosis?
- Most frequent nail disorders: **40% to 50%** of all nail diseases.
- Majority are **DLSO**: Begins with distal subungual keratosis, progresses proximally, leading to discoloration and nontransparency.
- **SWO**: Toenails show chalky-white patches; fingernails show inhomogeneous white discoloration.
- **PSO**: White to yellowish discoloration under the proximal nailfold, may lead to onycholysis.
- **Endonyx onychomycosis**: Rare form affecting only the nail plate, showing air-filled channels.
128
What is the etiology and pathogenesis of DLSO in onychomycosis?
- **DLSO**: Fungus grows from the tip of the digit through the hyponychium toward the nail bed, causing hyperkeratosis.
- The overlying nail plate acts as a barrier, leading to an inflammatory infiltrate in the nail bed.
- Yellow streaks or narrow wedges may be seen under the nail, indicating compressed fungi, termed **dermatophytoma**.
129
What diagnostic methods are used to confirm onychomycosis?
- Diagnosis should be confirmed by **direct microscopy** after clearing subungual keratotic debris with potassium hydroxide.
- **Culture** and **histopathology** are also used, with histopathology being doubly sensitive.
- Modern methods include **PCR** and **matrix-assisted laser desorption/ionization–time-of-flight spectroscopy** for fungal infection confirmation.
130
What are the differential diagnoses for onychomycosis?
- The most important differential diagnosis is **nail psoriasis**, which may also cause discoloration and subungual hyperkeratosis.
- Key differences include:
- **Pits** are common in nail psoriasis but rare in onychomycosis.
- Onycholysis in psoriasis has a brownish-reddish proximal margin, unlike in onychomycosis.
- Dermatoscopy shows an irregularly serrated proximal border in psoriasis, known as the **“aurora borealis” sign**.
131
What disease associations are linked to onychomycosis?
- Onychomycoses are associated with **tinea** of the hand and/or feet.
- More frequent in patients with **nail psoriasis**.
- Risk factors include **peripheral neuropathy**, **arterial and venous insufficiency**, and **traumatically damaged nails**.
- More commonly seen in **diabetic patients**.
132
A patient with HIV presents with chalky-white patches on the toenails with no shine. What is the diagnosis and causative organism?
The diagnosis is superficial white onychomycosis (SWO), commonly caused by T. rubrum in HIV patients.
133
A patient has a yellow streak under the nail extending proximally. What is this phenomenon called and its significance?
This phenomenon is called dermatophytoma, indicating huge amounts of compressed fungi in the nail bed.
134
A patient presents with a brownish-reddish proximal margin of onycholysis. What is the likely diagnosis and key distinguishing feature from onychomycosis?
The likely diagnosis is nail psoriasis. The key distinguishing feature is the brownish-reddish proximal margin, which is not seen in onychomycosis.
135
What is the prognosis for nail destruction in patients with severe total dystrophic onychomycosis?
The prognosis for nail destruction is good in more than 90% of patients, and complete recovery is possible even after severe total dystrophic onychomycosis.
136
What hygienic measures are important for managing onychomycosis?
Important hygienic measures include regular disinfection of shoes and socks, wearing open shoes whenever possible, changing footwear daily, and washing socks at 60°C (140°F).
137
What is the recommended treatment for onychomycosis when more than 50% of the nail is affected?
When more than 50% of the nail is affected, systemic treatment is indicated. Dermatophytes respond best to terbinafine (Lamisil) 250 mg daily, while yeasts and nondermatophyte molds are treated with itraconazole 400 mg/day for 1 week every 4 weeks.
138
What is clubbing and what conditions is it associated with?
Clubbing is characterized by enlarged finger and toe tips, giving a drumstick appearance. It is associated with chronic hypoxemia and cor pulmonale, and the nail size increases with pronounced longitudinal and transverse curvatures.
139
What are the characteristics of yellow nail syndrome?
Yellow nail syndrome is characterized by a triad of 1) yellow, thick, extremely slow-growing nails with onycholysis, 2) chronic sinus-bronchopulmonary infection, and 3) edema of the distal extremities.
140
What are Muehrcke lines and what do they indicate?
Muehrcke lines are two parallel white bands in the middle of the nail bed that do not move out, indicating severe hypoalbuminemia.
141
What are the characteristics of half-and-half nails?
Half-and-half nails are characterized by the proximal half of the nail being whitish, while the distal half tends to be brownish, indicating chronic renal insufficiency.
142
A patient presents with yellow, thick, slow-growing nails and chronic sinus-bronchopulmonary infection. What is the likely syndrome?
The likely syndrome is Yellow Nail Syndrome (YNS).
143
A patient with diabetes presents with onychomycosis. What systemic treatment is most effective for dermatophytes?
The most effective systemic treatment for dermatophytes is terbinafine (Lamisil) 250 mg daily.
144
A patient presents with clubbing of the nails. What is the diagnostic test to confirm this and its underlying cause?
The diagnostic test is the Schamroth sign, where the diamond-shaped window is absent. The underlying cause is chronic hypoxemia.
145
What are the psychological behaviors associated with nail disorders and their implications?
- **Onychophagia**: Chewing of nails, common in children and can persist into adulthood.
- **Perionychotillomania**: Pulling off hangnails, leading to a central depression of the nail.
- **Onychoteiromania**: Rubbing away of nails.
- **Onychotillomania**: Pulling nails out in pieces.
- **Onychotemnomania**: Using a cutting device to remove nails.
- **Onychodaknomania**: Psychotic behavior involving biting nails, often associated with deprivation syndrome.
These behaviors are difficult to treat and may require psychological support.
146
What are the drug reactions that can affect nail health and their associated findings?
| Drug Class | Nail Findings |
|------------|---------------|
| Cytostatic drugs | White lines, Beau lines, onychomadesis |
| Taxanes | Painful subungual hemorrhagic abscesses |
| Targeted anticancer therapies | Fragile nails, granulation tissue |
| Retinoids | Fragile nails, paronychia |
| Beta-blockers | Acral ischemia |
| Bleomycin | Digital ischemia, permanent nail loss |
| PUVA therapy | Longitudinal brown streaks |
| Tetracyclines and fluoroquinolones | Photoonycholysis |
| Acyclovir | Longitudinal melanonychias |
147
What are the nail findings associated with chronic diseases?
| Disease | Nail Finding |
|---------|--------------|
| Chronic hypoxemia | 1) Chronic hypoxemia |
| Chronic renal failure | 2) Chronic renal failure |
| Severe hypoalbuminemia | 3) Severe hypoalbuminemia |
| Wilson disease | 4) Wilson disease |
| Severe liver disease | 5) Severe liver disease |
| Chronic GI Disease | 6) Chronic GI Disease |
| Chronic sino-bronchopulmonary infection | 7) Chronic sino-bronchopulmonary infection |
148
What is the difference between habit tic deformity and Heller’s median canaliform dystrophy?
- **Habit tic deformity**: Characterized by a median split in the nail plate starting in the proximal portion, extending distally, and showing oblique furrows resembling a Christmas tree.
- **Heller’s median canaliform dystrophy**: Involves a similar appearance but is specifically associated with trauma and habitual behaviors affecting the nail structure.
149
A patient presents with transverse white nail discoloration. What is the likely cause?
The likely cause is high doses of arsenic.
150
A patient with obsessive-compulsive disorder presents with central depression of the nail and a washboard aspect. What is the diagnosis and treatment?
The diagnosis is perionychotillomania. Treatment includes psychological support and N-acetyl cysteine 1800-2400 mg/day.
151
A patient undergoing chemotherapy develops painful subungual hemorrhagic abscesses. What is the likely causative drug and preventive measure?
The likely causative drug is Taxanes. Preventive measures include the use of frozen gloves and socks.
152
A patient presents with photoonycholysis. What are the likely causative drugs?
The likely causative drugs are tetracyclines and fluoroquinolones.
153
What are the characteristics of Paronychia Congenita and its impact on nails?
Paronychia Congenita is associated with mutations in KRT6a, KRT6b, KRT.
154
What develops painful subungual hemorrhagic abscesses?
The likely causative drug is Taxanes. Preventive measures include the use of frozen gloves and socks.
155
What are the likely causative drugs for photoonycholysis?
The likely causative drugs are tetracyclines and fluoroquinolones.
156
What are the characteristics of Paronychia Congenita?
Paronychia Congenita is associated with mutations in KRT6a, KRT6b, KRT6c, KRT16, and KRT17. It leads to painful callus-like palmar and plantar hyperkeratoses, monstrous thickening of the subungual hyperkeratosis, and affects virtually all nails.
157
What are the clinical features of Ectodermal Dysplasia related to nails?
Ectodermal Dysplasia involves hereditary disorders affecting hair, nails, sweat glands, and teeth. The most common features include nails that are short, thickened, or brittle.
158
What is Nail-Patella Syndrome and how does it affect nails?
Nail-Patella Syndrome is caused by an LMXB1 mutation and is characterized by nail hypoplasia, particularly marked on the thumbs, with a triangular-shaped lunula.
159
What are the implications of congenital malformations of the big toe on nail health?
Congenital malformations of the big toe can lead to a triangular, thickened, oyster shell-like, and onycholytic nail.
160
What are the common types of nail tumors and their effects on nail structure?
Nail tumors can originate from all tissue components and may cause pressure on the matrix, resulting in a furrow in the nail plate.
161
What is the significance of Bowen disease in relation to squamous cell carcinoma (SCC) of the nail?
Bowen disease is the in situ form of SCC and is the most frequent malignant neoplasm of the nail.
162
What is the treatment of choice for squamous cell carcinoma of the nail?
The treatment of choice for squamous cell carcinoma of the nail is Mohs surgery.
163
What is the likely diagnosis for a patient with a triangular lunula and hypoplastic patella?
The likely diagnosis is Nail-Patella Syndrome, associated with LMXB1 mutation.
164
What is the diagnosis and treatment for a child with a triangular, thickened, oyster shell–like nail on the big toe?
The diagnosis is congenital malalignment of the big toe. Early treatment involves taping of the orthopedic abnormality.
165
What is an Onychocytic Matricoma and how is it characterized histologically?
An Onychocytic Matricoma is a longitudinal brownish to dirty-yellow lesion under the nail that shines through the plate.
166
What are the clinical features of an Onychomatricoma?
An Onychomatricoma presents as a thickened, funnel-shaped, yellow, striated nail that may show splinter hemorrhages.
167
What is the treatment for Ungual Fibrokeratoma?
The treatment for Ungual Fibrokeratoma is by incision around the tumor down to the bone and extirpation.
168
What are Myxoid Pseudocysts and how do they affect the nail?
Myxoid Pseudocysts are common pseudotumors in middle-aged and elderly individuals, often occurring in the proximal nailfold.
169
What is the significance of longitudinal melanonychia (LM) in nail evaluation?
Longitudinal melanonychia (LM) is a brown streaky pigmentation of the nail that does not primarily indicate the type of pigment responsible.
170
What are the four lesion types that can induce true longitudinal melanonychia (LM)?
The four lesion types are melanocyte activation, matrix lentigo, matrix nevus, and pigmented melanoma of the matrix.
171
What is the recommended approach for managing acquired matrix melanocyte proliferations in adults?
It is recommended to tangentially excise all acquired matrix melanocyte proliferations in adults.
172
What is the likely benign tumor for a patient with a longitudinal brownish to dirty-yellow lesion under the nail?
The likely benign tumor is onychocytic matricoma, characterized histologically by basaloid cells and keratin inclusions.
173
What is the diagnosis for a patient with a sausage-like lesion under the proximal nailfold?
The diagnosis is ungual fibrokeratoma, associated with tuberous sclerosis complex.
174
What is the diagnosis and treatment for a patient with an extremely painful digit tip and a violaceous red spot under the nail?
The diagnosis is a glomus tumor. Treatment involves meticulous enucleation of the tumor.
175
What are the four lesion types that can induce true longitudinal melanonychia?
The four lesion types are melanocyte activation, matrix lentigo, matrix nevus, and pigmented melanoma of the matrix.
176
What is the likely diagnosis for a nail tumor causing a longitudinal groove?
The likely diagnosis is myxoid pseudocyst, commonly associated with degenerative distal interphalangeal osteoarthritis.
177
What is the likely diagnosis for a nail tumor causing a V-shaped onycholysis?
The likely diagnosis is onychopapilloma. Treatment involves tangential excision of the lesion.
178
What is the likely diagnosis for a nail tumor causing a collarette-like margin?
The likely diagnosis is subungual exostosis, commonly occurring on the big toe.
179
What is the likely diagnosis for a nail lesion with tunnels containing capillaries?
The likely diagnosis is onychomatricoma. Dermatoscopic feature includes tunnels containing capillaries.
180
What is the likely diagnosis for a nail lesion with a sausage-like appearance?
The likely diagnosis is ungual fibrokeratoma. Treatment involves incision around the tumor and extirpation.
181
What is the likely diagnosis for a nail lesion with a longitudinal fissure and a tiny round keratotic tip?
The likely diagnosis is subungual filamentous tumor.
182
What is the likely diagnosis and treatment for a nail lesion with a violaceous lesion on one side of the matrix?
The likely diagnosis is myxoid pseudocyst. Treatment options include punctures, steroid injections, or surgery.
183
What is the likely diagnosis for a nail lesion with a reddish line extending distally?
The likely diagnosis is glomus tumor, characterized by extreme pain precipitated by shock or cold.
184
What is the likely diagnosis for a nail lesion with a brownish to dirty-yellow lesion under the nail?
The likely diagnosis is onychocytic matricoma, characterized by basaloid cells and keratin inclusions.
185
What is the prevalence of nail melanoma in light-skinned individuals compared to Asians and Africans?
Nail melanoma makes up 1.5% to 2.5% of all melanomas in light-skinned individuals, 10% to 20% in Asians, and up to 25% in Africans.
186
What is the significance of the Hutchinson sign in nail melanoma?
The Hutchinson sign indicates periungual spread of the in situ component of melanoma and is characterized by periungual pigmentation.
187
What are the common sites for nail melanoma?
The most common sites for nail melanoma are the thumbs, big toes, index fingers, and middle fingers.
188
What is the typical age range for the incidence of nail melanoma?
The peak incidence of nail melanoma is from the fifth to seventh decades of life, but it can also occur in children and the very old.
189
What is the prognosis for invasive nail melanomas?
The prognosis for invasive nail melanomas is poor, with 5-year survival rates of 15% to 20%.
190
What treatment is recommended for advanced nail melanomas?
For advanced nail melanomas, distal amputation is recommended.
191
What are the diagnostic challenges associated with amelanotic nail melanomas?
Approximately 25% to 33% of nail melanomas are amelanotic, posing great diagnostic challenges.
192
What is the relationship between UV exposure and nail melanoma?
UV exposure is not associated with nail melanoma.
193
What is the clinical significance of the diagnostic delay in nail melanoma?
The diagnostic delay for nail melanoma is often years or even decades, leading to many patients presenting with advanced tumors.
194
What is the role of dermatoscopy in diagnosing nail melanoma?
Dermatoscopy allows for the observation of signs such as the micro-Hutchinson sign, which aids in the diagnosis of nail melanoma.
195
What is the likely diagnosis for a longstanding oozing mass under the nail?
The likely diagnosis is onycholemmal carcinoma, characterized histologically as a slow-growing subungual tumor.
196
What is the likely diagnosis for a rapidly growing irregular pigmented lesion under the nail?
The likely diagnosis is subungual melanoma. A poor prognosis indicator is a diagnostic delay of years to decades.
197
What is the likely diagnosis for a patient with periungual pigmentation and a family history of melanoma?
The likely diagnosis is nail melanoma, associated with the Hutchinson sign.
198
What is the likely diagnosis for a pigmented streak in the nail with proximal widening?
The likely diagnosis is subungual melanoma. Proximal widening indicates rapid growth of the lesion.
199
What is the likely diagnosis for a nail lesion resembling a flat agglomeration of warts?
The likely diagnosis is Bowen disease (SCC in situ), associated with high-risk HPV types.
200
What are the different types of onychomycosis according to pathogens?
The types are Dermatophytes, Yeasts, and Nondermatophyte molds.
201
What are the most important differential diagnoses for onychomycosis?
The differential diagnoses include Nail psoriasis, Asymmetric gait nail unit syndrome, and Chronic nail dystrophy in the elderly.
202
What are the treatment modalities for onychomycosis approved by the FDA?
Treatment modalities include Ciclopirox 8% lacquer, Efinaconazole 5% solution, and Itraconazole.
203
What are the causes of digit clubbing?
Causes include Cor pulmonale, Cardiac insufficiency, and Chronic obstructive pulmonary diseases.
204
What are the drug-induced nail alterations associated with cytostatic and targeted therapies?
Alterations include White lines, Beau lines, and Onychomadesis.
205
What is methemoglobinemia?
A condition often seen in heavy smokers that affects the blood.
## Footnote
Example: Methemoglobinemia can lead to reduced oxygen delivery in the body.
206
What are the drug-induced nail alterations associated with cytostatic and targeted therapies?
Alterations include:
- White lines: Nail appearance change
- Beau lines: Nail growth interruption
- Onychomadesis: Nail shedding
- Muehrcke lines: White lines across the nail
- Hemorrhagic onycholysis and subungual abscesses: Nail bed issues
- Melanonychia: Dark streaks in the nail
- Granulation tissue: Tissue growth around the nail.
207
What is the differential diagnosis of longitudinal melanonychia based on age?
Differential diagnosis by age:
- Babies: Benign
- Children: Mostly benign
- Adolescents: Probably benign
- Adults until age 30 to 35 years: Suspicious
- Adults older than age 40 years: Highly suspicious
- Adults older than age 50 years: Probably melanoma.
208
What is the differential diagnosis of longitudinal melanonychia based on color and internal structure?
Differential diagnosis by color/structure:
- Regular light-brown band on a gray background: Functional LM
- Regular brown band on a brown background: Lentigo
- Regular brown band with dark brown spots on brown background: Nevus
- Irregular brown band with asymmetric, unevenly spaced lines of variable length, proximal widening of the band: Melanoma.
209
What is the ABCDEF rule for diagnosing nail melanomas?
The ABCDEF rule includes:
- **A**ge: Most occur between 40 and 70 years, higher in African Americans, native Americans, Asians.
- **B**rown: Brown to black band in the nail, breadth over 3 mm, irregular or blurred border.
- **C**hange: Rapid increase in width and growth rate, nail dystrophy does not improve despite adequate therapy.
- **D**igit: Thumb > big toe > index finger; single-digit involvement; very rarely more affected.
- **E**xtension of pigmentation: Hutchinson sign.
- **F**amily or personal history of melanoma or dysplastic nevi.
