week 5 skin Flashcards
1
Q
• What is erythema Nodosum? Causes?
A
o inflammation of the skin and subQ tissue (panniculitis) characterized by tender, red nodules on the shins
o Cause: infections, drugs, malignancy, inflammatory/granulomatous dx (sarcoidosis)
2
Q
• What are ssx of erythema Nodosum? Epidem?
A
o Ssx: indurated nodules that look like bruises, gradually changing color, with successive crops of nodules. Nodules are very painful. Mostly pretibial. Systemic symptoms such as fever, malaise, joint pain. spontaneous resolution in about 6 weeks.
o Age: peaks at 20-30 but can occur at any age. F>M (6x)
3
Q
• How is erythema Nodosum diagnosed? Ddx?
A
o By H & P, but must look for underlying disorder. Biopsy, ESR, CRP ANA, CBC, chest x-ray (sarcoid), ASO-titer (anti-streptolysin O) or pharyngeal culture (for group A beta-hemolytic strep).
o DDx: vasculitis, pretibial myxedema, lymphoma
4
Q
• What is a sweating disorder? Ssx? Dx? Ddx?
A
o Miliaria: (heat rash) Accumulation of sweat beneath eccrine sweat ducts results in obstruction by keratin at the level of the stratum corneum.
o Ssx: Pruritus is common. More in kids/babies. Small red papules with mild itching, occasional pustules
o Dx: Hx&P
o Ddx: baby acne
5
Q
• What are the bacterial skin infections?
A
o Cellulitis; cutaneous abscess; erysipelas; erysipeloid; erythrasma; folliculitis; furuncle; carbuncle; impetigo
6
Q
• What is cellulitis? Causes?
A
o acute bacterial infection of the skin
o Causes: most common in adults S. aureus, GAS. Children Hib, GAS, S. aureus. Varies with location. Immunocompromise will predispose. IV drug use
7
Q
• What are ssx of cellulitis? Distribution?
A
o Ssx: local erythema, heat, edema and tenderness, with lymphangitis and regional lymphadenopathy. Systemic symptoms, if present, include fever, chills, tachycardia, headache, hypotension or delirium (may precede skin sxs).
o Distribution: Adults- lower leg most common. Children cheeks, periorbital, head, neck
8
Q
• How is cellulitis diagnosed? Ddx?
A
o Diagnosis: by H & P. CBC. Culture of exudates or aspirate. Blood cultures if immune compromised. Blood cultures of infected tissue if not responding to therapy.
o DDX: DVT, gout, CPPD, septic arthritis, stasis dermatitis, insect bite, erysipelas
9
Q
• What is a cutaneous abscess? Ssx? Dx? Ddx?
A
o localized collection of pus under the skin
o ssx: Painful, tender, indurated and erythematous, varying in size from 1-3 cm typically, but mb larger. May be accompanied by local cellulitis, lymphangitis, LAD, fever.
o Dx: by H & P, CBC. Gram stain or culture in immunocompromised patients.
o DDX: hidradenitis suppuritiva, ruptured epidermal cysts
10
Q
• What is erysipelas? Cause? Complications?
A
o superficial cellulitis with dermal lymphatic involvement (streaking)
o Cause: GAS, immunocompromised
o Complications: scarlet fever, fat necrosis, gangrene. Sudden onset
11
Q
• What are ssx of erysipelas? Distribution?
A
o Ssx: Shiny, raised, indurated and plaque-like lesions with distinct margins. Commonly high fever, chills, and malaise, or maybe no systemic symptoms. It has sharp borders, raised, red (deep), hot plaque that spreads rapidly. Regional LAD and tenderness, and may see vesicles, bullae, petechiae. Itching, burning, and pain may be severe. Red, painful streaks along lymph
o Distribution: Legs most common, then face
12
Q
• How is erysipelas diagnosed? Ddx?
A
o By H & P, CBC, blood culture in toxic-appearing patients. Direct culture is often not useful
o DDX: Face – herpes zoster, contact derm.
13
Q
• What is erysipeloid?
A
o Like erysipelas except a different bacteria (Erysipelothrix). Violet on the hands and forearms and is not hot, though may be tender with fever and malaise. Rare.
14
Q
• What is erythrasma? Ssx? Dx? Ddx?
A
o Superficial intertriginous infection with Corynebacterium.
o Ssx: Occurs in toe webs, between fingers, genitals (pink or brown patches) with scaling, fissuring and maceration. May be patchy on the trunk.
o Dx: Coral red fluorescence with Wood’s lamp, no hyphae, skin scraping w/KOH
o DDX: tinea, candida
15
Q
• What is folliculitis? Causes? Ssx?
A
o Inflammation of the hair follicle. Many different types
o Cause: S. aureus, fungal, persistent trauma, systemic corticosteroids
o Ssx: Pustule or inflammatory nodule that surrounds a hair follicle. Superficial or deep. Mild itching or pain. Abrupt onset May be chronic.
16
Q
• What is “Hot tub” Folliculitis?
A
caused by Pseudomonas following exposure to contaminated water. High rate of infxn in kids. Occurs 8hrs-5days post hot tub. Trunk, groin most common
17
Q
• What is distribution of folliculitis? Dx? Ddx?
A
o Distribution: buttocks, upper legs, face, neck, sternum and upper outer arms most common but can be anywhere except hands and feet
o Dx: by examination. KOH to r/o dermatophyte
o DDX: acne, follicular keratosis,
18
Q
What is a furuncle? Ssx? Age?
A
o acute tender nodules, caused by S. aureus.
o Ssx: A deep dermal or subq, red, swollen and painful mass and drains to the surface. Pustule 5-30 mm with central necrosis and pus discharge. May be recurrent. A ruptured lesion heals with deep violaceous scar. Afebrile
o Age: uncommon in children
19
Q
• What is distribution of a furuncle? Sx? Ddx?
A
o Distribution: neck, under breasts, buttocks, groin most common
o Dx: by examination. Culture may be beneficial dt MRSA
o Ddx: Folliculitis, Hidradenitis suppurativa, insect/spider bite, ruptured pilar cyst, cystic acne
20
Q
• What is a carbuncle? Ssx? Dx?
A
o Cluster of furuncles with multiple draining orifices.
o Ssx: Usu on neck, face, breasts and buttocks. Uncomfortable and may be painful, accompanied by fever.
o Dx: by examination. Culture if recurrent or immunocompromised.
21
Q
• What is impetigo? Causes? Ssx?
A
o superficial acute skin infection with crusting
o Cause: S. pyogenes, S. aureus. Warm moist climate, poor hygiene
o Ssx: Clusters of vesicles or pustules that rupture and develop honey colored crust. Scaling borders. Satellite lesions often present. May see regional LA. May be pruritic.
22
Q
• What is distribution of impetigo? Age? Dx? Ddx?
A
o Distribution: face, shins, extensor surface of forearms
o Age: common in children
o Dx: by examination. Culture is more common now dt MRSA.
o DDX: atopic, contact dermatitis, perioral dermatitis, herpes simplex, herpes zoster, tinea
23
Q
• What are the fungal skin infections?
A
o Candidiasis; dermatophytoses; tinea versicolor
24
Q
• What is candidiasis? Causes? Ssx?
A
o Skin infection with Candida sp, most often Candida albicans (70-80%).
o Causes: Immunosuppression, sugar dysregulation, antibiotics, oral contraceptives
o Ssx: intertriginous, erythematous, well-demarcated, pruritic patches of varying sizes and shapes. Surface is often glistening. Intense inflammation with satellite lesions around the main area.
25
• What are the types of candidiasis? Dx? Ddx?
o Many different types based on location: Balanitis, Diaper Dermatitis, Intertrigo, Vulvovaginitis, Oropharyngeal
o Dx: By examination, presence of yeast and pseudohyphae on KOH prep, fungal culture or DNA probe.
o DDx: changes with location. Dermatophytoses, allergic derm, herpes, molluscum, psoriasis, contact derm, strep cellulites, seborrheic derm, erythrasma,
26
• What is dermatophytoses? Ssx? Dx?
o fungal infections of keratin in the skin and nails. Caused by Epidermophyton, Microsporum, and Trichophyton.
o Vary by site. Recurrent with little or no inflammation. Mildly pruritic, erythematous scaling lesions.
Dx: by appearance, Wood’s Lamp, skin scraping and a KOH prep
27
What are the types of tinea?
o Barbae, capitis, corporis, cruris, pedis
o Dermatotyphid reaction
o Versicolor
28
• What is tinea barbae? Dx?
o Tinea barbae: uncommon. Develops slowly. 2 patterns- ringworm and follicular. Pruritic, at time painful and swollen. Secondary bacterial infections can occur.
o Dx: Examine skin scraping and plucked hair with KOH (hairs will come out easily if fungal infxn) fungal cultures and biopsy can be helpful.
29
• What causes tinea capitis? Epidem? 4 patterns? Ssx? Ddx?
o caused by Trichophyton tonsurans.
o Epidem: More common in African Americans and Hispanic and those living in close proximity. Children most effected.
o 4 patterns- seborrheic derm, inflammatory, “black dot” pattern and pustular. s/sx change with each.
o Ssx: KOH examination of lesional hairs demonstrates fungal hyphae arranged in a longitudinal direction within the hair shafts. Culture can be performed on Sabouraud’s medium and Wood’s lamp examination of infected hairs reveals a characteristic sliver-blue fluorescence
o DDX: psoriasis, seborrheic dermatitis
30
• What are ssx of tinea corporis? Dx? Ddx?
o Ssx: pruritic, circular or oval, erythematous, scaling patch/plaque that spreads centrifugally. Central clearing follows, while the active advancing border, a few millimeters wide, retains its red color and with cross lighting can be seen to be slightly raised.
o Dx: KOH will show hyphae, culture may be necessary
o DDX: pityriasis rosea, drug eruptions, nummular dermatitis, erythema multiforme, tinea versicolor, psoriasis
31
• What causes Tinea cruris (“jock itch”)? Ssx? Sex? Dx? Ddx?
o Causes: Obesity, diabetes and immunodeficient states.
o Ssx: erythematous patch high on the inner aspect of one or both thighs (opposite the scrotum in men). It spreads centrifugally, with partial central clearing and a slightly elevated, erythematous, sharply demarcated border that may show tiny vesicles that are visible only with a hand glass, spares the scrotum.
o M>F
o Dx: KOH prep from scraping of an active border.
o DDX: contact dermatitis, psoriasis, Candida, erythrasma, seborrheic derm
32
• What is Tinea pedis (“athlete’s foot”)? Dx? Ddx?
o common. intensely pruritic, sometimes painful, erythematous vesicles or bullae between the toes or on the soles, frequently extending up the instep. Unilateral or bilateral. Secondary eruptions at distant sites, called an Id reaction, examine hands.
o Dx: skin scarping.
o DDX: dyshidrotic eczema, contact dermatitis, psoriasis
33
• What is the Dermatophytid Reaction (“id” reaction)?
o distant site inflammatory reaction during fungal infection. Sterile.
34
• What is tinea versicolor? Ssx? Distribution? Dx? Ddx?
o superficial fungus infection with Malassezia furfur (a saprophysic yeast)
o ssx: hypopigmented, hyperpigmented, or erythematous macules with scaling patches. Lesions are asx.
o Distribution: trunk and proximal upper extremities
o Dx: Direct microscopy shows “spaghetti and meatballs” appearance of broad hyphae and clusters of budding cells, Wood's lamp will reveal yellow to yellow-green fluorescence in some cases
o DDX: Vitiligo, pityriasis rosea, tinea corporis, Seborrheic dermatitis, Erythrasma
35
• What are the parasitic skin infections?
o Cutaneous larva migrans; lice (pediculosis); scabies
36
• What causes cutaneous larva migrans (“Creeping eruption”)? Ssx? Distribution? Dx? Ddx?
o caused by hookworm larva (Ancylostoma) from dog and cat excrement.
o Ssx: intense pruritis, erythema and papules at site of entry, winding tail of inflammation- serpiginous. usually occurs about 3 weeks after exposure.
o Distribution: feet/ankles, buttocks, backs of legs and back
o Dx: history and appearance, CBC can show eosinophila, CXR
o DDX: scabies
37
• What is lice (pediculosis)? Ssx? Distribution? Dx? Ddx?
o Wingless, blood sucking insects that infect the head (Pediculus humanus capitius), body (Pediculosis humanus corporis), or pubis (Phthirus pubis).
o Ssx: Severe pruritis. May see excoriations from scratching. Red puncta from bites. Nits on hair shaft 1cm from scalp- gray/white. May see brown specks of excrement on skin or clothing.
o Distribution: scalp, body hair, pubic hair
o Dx: Demonstration of living lice in wet hair using a fine-toothed comb. Also will fluoresce under Wood’s lamp.
o DDx: seborrheic derm, impetigo, insect bites
38
• What is scabies? Ssx? Distribution? Dx? Ddx?
o Infection of skin with scabies mite Sarcoptes.
o Ssx: Burrows are fine, wavy lines in the skin 2-10 mm long, covered often by lichenified skin. Intensely pruritic, esp at night. May also see erythematous papules without many burrows. Others in family/living quarters will be affected. Itching will continue after treatment due to allergic response not active infestation.
o Distribution: hands, arms, feet, gluteal fold, axilla, back of the knees
o Dx: Burrows are pathognomonic. May do microscopic examination of burrow scrapings. Apply mineral oil to the burrow, vesicle or papule and scrape with a #15 blade, prepare slide. Dx is often made only by Hx and PE.
o DDX: insect bites, fungus, eczema, folliculitis, impetigo
39
• What are the viral skin dzs?
o Molluscum contagiosum; warts (verrucae vulgaris); varicella; herpes simplex; zoster; roseola infantum; hand foot and mouth dz; viral exanthems; measles; rubella
40
• What is collsucum contagiosum? Ssx? Age? Distribution? Dx? Ddx?
o caused by pox virus in epidermal cells
o ssx: Smooth flesh colored umbilicated dome, hard; cheesy core; may become inflamed or secondarily infected. Asx. Up to 15 mm in diameter in immunocompromised. Lesions persist for 6-9 months
o Age- Any but more common 3-9yrs
o Distribution: face, arms, chest, genitals (when sexually transmitted)
o Dx: By appearance. Biopsy will show “molluscum bodies” in keratinocytes. Biopsy should be used in immunocompromised pts
o DDX: Folliculitis, milia, verrucae
41
• What are warts (verrucae vulgaris)? 6 types? How are they diagnosed?
o Benign contagious neoplasms caused by HPV
o Common, filiform; flat; plantar; mosaic; condylloma accuminata
o Dx: By appearance, biopsy if necessary- esp if it doesn’t respond to tx to r/o squamous cell carcinoma
42
• What is the common wart? Ssx? Distribution? Age?
o verruca vulgaris: dome shaped, round or irregular, rough; colors can be gray, yellow, brown, black, skin colored; 2-10 cm. Skin lines are interrupted by hyperkeratosis. Black puncta when scraped with pinpoint bleeding
o Usually asx.
o Distribution: hands, knees, genitalia, feet.
o Age- any but peak at 12-16yrs
43
• What is a filiform wart? Flat wart? Plantar wart?
o Filiform: long narrow small warts, soft, seen on eyelids, face, neck
o Flat: Smooth, flat, yellow brown or flesh colored; 2-3 mm; backs of hands, lower legs and face
o Plantar: soles of the feet; single or multiple; painful and callused. Different from corns/calluses – black puncta present.
44
• What is mosaic wart? Condylloma accumianta?
o Mosaic: multiple plantar warts
o Condylloma accuminata (genital warts): soft moist papules or plaques on perineum, external genitalia, anus, vagina, cervix;
45
• What is varicella? Ssx? Distribution?
o chickenpox): acute highly contagious vesicular eruption caused by a primary infection with varicella (HHV-3).
o Ssx: Prodrome (more in kids > 10) with malaise, chills, headache, sore throat, anorexia and dry mouth. Then the rash starts and itching is severe. Lesions are papules, macules, vesicles, pustules and crusts all at the same time.
o Distribution: begins on trunk and spreads to face and extremities. Most lesions present of trunk Lesions can occur in mouth and vagina
46
• When is varicella infectious? Impact of vaccine?
o Infectious from 2 days before the lesions appear till all lesions crust over.
o 20% of pt’s vaccinated will still get varicella- although it is atypical dz- maculopapular rash
47
• How is varicella diagnosed? Ddx?
o Dx: Characteristic rash. Culture or Tzanck smear in questionable cases
o DDX: other viral diseases, contact dermatitis, zoster, folliculitis, impetigo
48
• What is herpes simplex? Ssx? Distribution?
o recurrent viral infection with intraepidermal infection by HSV 1 or 2.
o Ssx: Single or clustered vesicles. Systemic symptoms with primary infections: fever, malaise, myalgia, headache and regional LA. Prodromal period of tingling or discomfort in many, then appearance of small vesicles on a red base. They rupture and ulcerate. Often painful. They dry up and are completely healed in about 2-6 weeks. Recurrent infection often follows physical or emotional stress
o Distribution: mouth, eyes, genitals
49
• What is herpetic whitlow? Dx of HSV? Ddx?
o Herpetic whitlow: infects distal phalanx with a very painful lesion that swells.
o Dx: characteristic lesions. Tzanck smear (superficial scraping from newly ruptured vesicle, then stained, showing multinucleated giant cells). Definitive dx is with culture of freshly ulcerated lesion.
o DDX: impetigo, eczema, zoster, hand foot and mouth dz, aphthous stomatitis
50
• What is herpes zoster? Ssx?
o shingles: latent varicella (HHV type 3) infection
o ssx: Virus remains in the nerve roots and erupts along the associated dermatome. May start with radicular pain and itching for 2-3 days, followed by herpetic rash. May see systemic symptoms. There may be severe pain, scarring, or post herpetic neuralgia (sharp, intermittent, or constant) which can be debilitating. Lesions usually lasts about 5 days. Pain may last weeks, months, years, or indefinitely.
51
• What is Distribution of zoster? Dx? Ddx?
o Distribution: follows dermatome, which can be variable but almost never crosses the midline
o Dx: pathognomonic rash. Tzanck Smear, differentiate virus by culture.
o DDX: changes with stage of dz. Before rash onset: MI, pleurisy, migraine. After lesions appear: HSV, primary varicella
52
• What is roseola infantum? Ssx?
o Exanthem subitum: Infection of infants or young children with HHV-6 (or 7).
o Ssx: 10 day incubation, with 3-5 days of high fever which subsides when the rash appears. May see febrile convulsions. Child is generally alert and active. Cervical and posterior cervical LAD. Rash is present for a few hours to a few days, and possibly unnoticed. Rash may only occur 30% of time.
53
• What is distribution of roseola infantum? Age? Dx? Ddx?
o Distribution: Prominent macular rash on chest and abdomen, less so on face and extremities
o Age: 90% <2yrs
o Dx: Hx and PE, virologic studies in immunocompromised or atypical dz
o DDX: Measles, Rubella, Enteroviral infections, Erythema infectiosum, Scarlet fever, drug allergy
54
• What is hand foot and mouth dz? Ssx? Distribution? Age? Dx? Ddx?
o Febrile disorder caused by Coxsackie virus
o Ssx: vesicular eruption of skin and mucosa (3-6mm), may have fever, myalgia, LA, abd pn, lack of appetite, poor nursing (dt pn). Lesions in mouth are painful. Lesions heal in 7 days
o Dist: buccal mucosa, tongue, palms of hands and feet, occasionally buttocks or genitals.
o Age: <5yrs most common
o Dx: Hx & PE.
o DDX: varicella, herpes, herpangina, aphthous stomatitis
55
• What is viral exanthems?
o by blood borne viruses initiating a vascular response in the skin. Most present with a prodrome of fever and malaise.
56
• What is measles? How is it spread? Incubation? Complications?
o Rubeola, Morbilli: Extremely communicable viral infection by a paramyxovirus.
o Spread by secretions from nose, mouth, throat during prodromal and early eruptive phase.
o Has an incubation time of about 7-14 days, with prodrome around the 9th day.
o Complications: encephalitis and secondary infection.
57
• What are ssx of measles? Distribution?
o Ssx: prodrome with 3-4 days of fever, coryza, conjunctivitis and photophobia, cough and Koplik spots (these are 1 to 3 mm whitish, grayish, or bluish elevations with an erythematous base on buccal and vaginal surface). Rash appears after 2-3 days of initial symptoms and is morbilliform, maculopapular, and blanching. Lasts 5-6 days.
o Dist: begins on the face and spreading cephalocaudally and centrifugally to involve the neck, upper trunk, lower trunk, and extremities
58
• How is measles diagnosed? Ddx?
o Dx: Clinical – identification of Koplik spots or rash. BUT! In countries with very low measles prevalence, diagnosis should consist of evaluation of paired acute and convalescent sera for anti-measles IgM and IgG; at least fourfold increase in anti-measles antibody titer is indicative of infection CBC (Leukopenia, T-cell cytopenia, and thrombocytopenia). CXR(may demonstrate interstitial pneumonitis)
o DDX: during prodrome: many. During rash: Scarlet fever, rubella, drug reactions, roseola, erythema infectiosum, Rocky Mountain spotted fever, infectious mononucleosis, Kawasaki disease, toxic shock syndrome.
59
• What is rubella? Ssx?
o German Measles: Infection caused by the RNA Rubella virus.
o Ssx:: Usually mild incubation about 14-21 days, with brief prodrome of fever and malaise, with a similar fainter rash, starting on the face and moving downward. Rash is more pinpoint pink maculopapules, and may have petechiae on the soft palate. Very mild dz and may be asx. Does not darken or coalesce.
60
• What is distribution of rubella? Dx? Ddx?
o Dist: first appears on the face, spreads caudally to the trunk and extremities, and becomes generalized within 24 hours
o Dx: Characteristic LAD and rash. Only need lab dx in pregnant women and newborns- rubella-specific IgM antibodies using an enzyme immunoassay (EIA)
o DDX: measles, scarlet fever, drug rashes, erythema infectiosum
61
• What are the pigmentation disorders?
o Vitiligo; hyperpigmentation; melisma/chloasma; lentigines
62
• What is vitiligo? Ssx? Associated with?
o Idiopathic condition lacking in melanocytes
o Ssx: Pigmented areas that are sharply demarcated and often symmetric. Spots are white with no scale. Patchy and irregular, ranging from focal spots, to entire body segments, or most of skin surface.
o Associated with autoimmune diseases such as thyroid disease, pernicious anemia, systemic lupus erythematosus, and Addison's disease
63
• How is vitiligo diagnosed? Ddx?
o Dx: obvious on examination. Lesions accentuated under Wood’s Lamp in light skinned pts. thyroid function, CBC, and fasting blood glucose level
o DDX: tinea versicolor, Postinflammatory hypopigmentation, Chemically induced depigmentation, Pityriasis alba
64
• What are the hyperpigmentation disorders?
o Multiple causes, may be focal or diffuse.
| o Include melisma, lentigenes
65
• What is melisma/chloasma? Ddx?
o macular hyperpigmentation of the face usually seen in pregnant women or using OCP, more in dark skinned races, resulting from an increase in melanin due to estrogen stimulation and UV light. Sharply delineated patches usually on the face. Fades incompletely when the cause is removed.
o DDX: post inflammatory hyperpigmentation
66
• What are lentigines?
o Lentigo, singular: flat, tan or brown spots on sun-exposed areas, usu face or back of hands. Due to chronic sun exposure.
67
• What are the hair disorders?
o Alopecia; hirsuitism
68
• What is alopecia? 2 classifications? Dx?
o Baldness
o Non-scarring; scarring
o Dx: examine ratio of anagen and telogen hairs to assess if there is normal ratio of resting hairs. Occasional biopsy needed. Look for underlying cause with appropriate labs.
69
• What are the 7 types of non-scarring alopecia?
o Male pattern baldness: androgenic
o Female pattern: androgenic, starts around menopause.
o Diffuse: dx by pulling 2-3 dozen hairs- if >5 hairs with the bud come out. Triggered by weight loss, stress, pregnancy (or after pregnancy), illness.
o Toxic: related to chemotherapeutic drugs
o Alopecia areata: autoimmune, toxic, genes, infections, drugs, and vaccinations, have been implicated in triggering episodes of alopecia areata. severe stress, especially emotional stress, can precipitate. S/Sx smooth, circular, discrete areas of complete hair loss that develop over a period of a few weeks. Can be whole body.
o Trichotillomania- a psychological disorder related to OCD where pt pulls out hair
o Tinea capitis- see notes above.
70
• What is Scarring alopecia?
o Cutaneous lupus, deep bacterial infection, ulcers, granulomas, syphilis, tinea
71
• What is hirsuitism? Dx?
o excess hair in females in areas not normally hairy.
o Dx: Serum free/total testosterone, DHEA sulfate, FSH, LH, prolactin, TSH (to check for presence of thyroid dysfunction). Often related to PCOS
72
• What are the nail disorders?
o Onychomycosis; paronychial infections
73
• What is onychomycosis? Cause?
o Fungal infection of nail plate and/or bed
o usually caused by dermatophytes but can also be caused by yeast. Risks for developing are older age, swimming, tinea pedis, psoriasis, diabetes, immunodeficiency, genetic predisposition, and living with family members who have onychomycosis
74
• What are ssx of onychomycosis? Sx? Ddx?
o Ssx: Nails have asx patches of white, brown, or yellow discoloration and deformity, and may thicken.
o Dx: by appearance, KOH microscopy, if negative then nail culture or histopathologic examination of nail plate clippings
o DDX: Nail dystrophies: psoriasis, eczematous conditions, senile ischemia (onychogryphosis), trauma, lichen planus, iron deficiency
75
• What is Paronychial infections? Ssx? Dx?
o periungual infection
o ssx: develops along nail margin, becomes painful, warm, erythematous, and swollen. Pus along the nail margin, or beneath the nail.
o Dx: by examination.
76
• What are the types of benign tumors?
o Dermatofibroma; epidermal cyst; keloid; lipoma; nevi’ seborrheic keratosis; arcochordon; some vascular lesions
77
• What is dermatofibroma? Ssx? Distribution? Age? Ddx?
o a benign proliferation of fibroblasts
o ssx: epidermal thickening and hyperpigmentation; small red to brown papule. Does not grow. Usually a solitary lesion but can have up to 10 at one time. Can follow an insect bite or trauma. firm lesions, 0.3 to 1.0 cm in diameter, that are nontender and that dimple when pinched together
o Dist: most often on lower extremity
o Age: adults
o DDX: nevi, basal cell carcinoma. if continues to grow consider dermatofibroma protuberans (malignant)
78
• What is an epidermal cyst? Ssx? Distribution? Ddx?
o epidermally lined cyst containing keratinous material in the dermis
o ssx: contains keratin; firm flesh colored moveable nodule in the skin, 1-3 cm w/ often with a central punctum; insignificant, non tender, unless it ruptures.
o Dist: face, base of ears, and trunk
o DDX: sebaceous cysts , lipoma, if very firm r/o malignancy or if there are multiples in strange locations r/o Gardner's syndrome which is epidermal cysts associated with colon cancer.
79
• What is a keoild? Ssx? Epidem? Dx? Ddx?
o excess fibroblastic proliferation following trauma and scarring;
o ssx: elevated, shiny, firm protuberant nodule on the site of injury. Can have claw like extensions.
o African and Asian descent are most susceptible to the development of keloids
o Dx: by appearance.
o DDX: Hypertrophic scar- stays confined to original wound margin
80
• What is lipoma? Epidem? Ssx? Distribution? Dx? Ddx?
o subcutaneous nodules of adipocytes
o More common in women. May have one or more.
o ssx: rubbery nodule below dermis that is moveable. Usu asx. Overlying skin is normal. Varies in size. Grows very slowly
o Dist: trunk, forearms, and neck
o Dx: Hx & PE. If it is rapidly enlarging, or is firm rather than soft, a biopsy is indicated.
o DDX: Epidermal cysts.
81
• What are nevi? Dx? Ddx?
o moles: circumscribed, often pigmented or flesh colored macules, papules or nodules composed of melanocytes.
o Dx: H&P, always biopsy suspicious lesions (changing or irregular borders, color changes, painful, or bleeding/ulcerating/itching)
o DDX: melanoma, seborrheic keratosis, skin tag, wart
82
• What is seborrheic keratosis? Ssx? Distribution? Age? Ddx?
o benign neoplasm resulting in pigmented superficial lesions that usually appear warty, or may be smooth papules.
o Ssx: "stuck on,'' warty, well-circumscribed, often scaly hyperpigmented lesions located most commonly on the. Close inspection with a hand lens often will demonstrate the presence of horn cysts or dark keratin plugs. Lesions should almost be able to be picked off with a no. 15 blade. Number of lesions ranges from 1-100’s.
o Dist: trunk, face, and upper extremities
o Age: generally in older adults but not a rule
o DDX: warts, nevi, melanoma, pigmented basal cell carcinoma.
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• What is acrochordon? Ssx? Distribution? Dx? Ddx?
o pedunculated fibroma or skin tag (lots of different names)
o ssx: asx, fleshy skin tumor; skin colored or pigmented. Can be pedunculated lesions on narrow stalks. Soft. Can get irritated by friction and bleed. Perianal skin tags are common in patients with Crohn's disease
o Dist: neck, axilla, groin, under breasts, eyelids
o Dx: appearance
o DDX: warts, nevi, neurofibromas
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• What are the skin cancers?
o BCC; malignant melanoma; SCC
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• What is BCC? Ssx? 3 forms?
o Superficial, slow growing papule or nodule that derives from epidermal basal cells.
o Ssx: Highly variable appearance from a small shiny, firm almost translucent nodule to crusty flat lesions to what looks like dermatitis.
o 3 forms: nodular (60%), superficial (30%), and morpheaform (10%)
o Nodular usually starts as a papule that slowly grows and develops into a “rodent ulcer” with a shiny pearly border, telangiectasia and a central ulcer. Alternately crust and heal.
o Superficial has a slightly scaly papule or plaque that is light red in color; the lesion may be atrophic in the center and usually is rimmed with fine translucent micropapules.
o Morpheaform lesions are smooth, flesh-colored, or very lightly erythematous papules or plaques that are frequently atrophic
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• What is age of BCC? Distribution? Dx? Ddx?
o Age: any but more common >40
o Dist: face, neck and scalp most common, then shoulders and arms (think sun)
o Dx: Biopsy
o DDX: nevi, seborrheic keratosis, dermatitis, scars, molluscum, squamous cell carcinoma
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• What is malignant melanoma? Ssx? Warning ssx? Major and minor?
o Arises in melanocytes in skin & mucus mem., eye, or CNS.
o Ssx: Vary a great deal in appearance but usually pigmented
o Warning SSx of melanoma development in previously benign-appearing mole: use the ABCDE rule and/or the revised Glasgow seven-point checklist (1 major requires referral)
o Major: Change in size/new lesion, shape, color
o Minor: Diameter >=7mm, Inflammation, Crusting or bleeding, Sensory change
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• What are the types of melanoma?
o lentigo-maligna melanoma (15% of melanoma): slow onset and progression. on face or sun exposed areas; 2-6 cm flat, tan or brown macule with darker spots, irregular border and surface, or a plaque with raised indurated edges, colored spots, nodules
o Superficial spreading (2/3 of melanoma): arise from a pre-existing lesion. diagnosed when smaller than lentigo melanoma. Mostly on women’s legs and men’s torsos. Plaque with irregular raised, indurated, tan or brown areas, with white, red black or blue-black spots.
o Nodular: dark protuberant papule or plaque varying in color; grows fast; may not be pigmented
o Acrolentiginous: Arise in areas of non-hair bearing skin; soles, palms, and subungual skin
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• How is melanoma diagnosed? Ddx?
o Dx: biopsy
| o DDX: basal cell carcinoma, seborrheic keratosis, benign nevi/lentigo, dermatofibroma, warts
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• What is SCC? Ssx? Distribution? Dx? Ddx?
o malignant tumor of epithelial keratinocytes that invades the dermis.
o Ssx: Usu on sun exposed areas; Appearance is highly variable, but usu starts as a red papule or plaque with a scaly rough surface, or sometimes is nodular like a wart. Can form cutaneous horns. Eventually ulcerates or bleeds, invades tissue and can metastasize.
o Dist: sun exposed areas
o Dx: Biopsy
o DDX: actinic keratosis, seborrheic keratosis, basal cell carcinoma.
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What are 6 types of Nevi?
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o Lentigo:
o Junctional nevus:
o Compound nevus:
o Intradermal nevus: elevated;
o Halo nevus:
o Atypical/Dysplastic nevus:
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What is a lentigo nevus?
o Lentigo: hyperpigmented macule due to increased melanocytes; darker, sparser, does not darken or multiply with sun. <4mm
o
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what is a junctional nevus?
o Junctional nevus: light brown-black. usually flat but can be slightly raised, pigmented; 1-10 mm; palms, soles, genitals.
o
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what is a compound nevus?
o Compound nevus: light to dark brown, smooth and dome-shaped or papillomatous , may be very elevated; involved epidermis and dermis. 3-6 mm.
o
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what is a intradermal nevus?
o Intradermal nevus: elevated; flesh colored to brown; smooth, dome-shaped, papillomatous, or pedunculated with a soft, rubbery texture. Can be hairy or warty. Occasionally, they have speckles of brown pigmentation or pseudo-horn cysts 3-6 mm.
o
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what is a halo nevus?
o Halo nevus: pigmented compound or intradermal nevus; surrounded by a halo of depigmented skin; immune phenomenon
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What is an atypical nevus?
o Atypical/Dysplastic nevus: irregular pigmented nevus from tan to dark brown; indistinct borders, mild asymmetry, can be flat or elevated areas in the same mole; may be genetic; large (>6 mm) and mostly on covered areas; usually see many on the person. Use the “ABCDEF” to assess– pt at greater risk for melanoma
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What is the glasgow 7 point checklist for melanoma?
Major: change in size, shape, color
minor: diameter >7mm, inflammation, oozing, change in sensation
