Dermatology Flashcards
(63 cards)
1
Q
Eczema definition
A
Papules and vesicles on an erythematous base occuring on flexor surfaces.
2
Q
Eczema epidemiology
A
- 20% prevalence <12 yo
- Atopic most common
3
Q
Eczema aetiology
A
- Primary genetic defect causing loss of function of filaggrin protein causing a defect in skin barrier function
- Family history of atopy usually present
4
Q
Eczema presentation
A
- Itchy, erythematous, dry scaly patches on flexor surfaces (face and extensor surfaces in infants)
- Acute lesions: erythematous vesicular and exudative if infected
- Chronic scratching can lead to excoriation and lichenification
- Pitting and ridging of nails
5
Q
Eczema management
A
- Avoid exacerbating agents
- Emolients
Topical steroids for flares:
- dipnovate
- dermovate
- immunomodulators for steroid sparing agents
Oral:
- antihistamines for symptomatic relief
- antibiotics (flucloxacillin) for secondary bacterial infection
- acyclovir for secondary herpetic infection
Severe non-responsive cases:
-Oral steroids –> phototherapy –> immunosuppressants (methotrexate, ciclosporin) –> biologics
6
Q
Psoriasis definition
A
Chronic inflammatory skin disease caused by hyperproliferation of keratinocytes and inflammatory cell infiltration
7
Q
Psoriasis aetiology
A
Variants:
- Chronic plaque - most common
- Guttate - raindrop lesions
- Seborrheic
- Flexural
- Pustular (palmar-plantar)
- Erythrodermic (total body redness)
Complex interaction between genetic, immunological and environmental factors
Precipitating factors: trauma, infection, drugs, stress, alcohol
8
Q
Psoriasis presentation
A
- Well demarcated erythematous scaly plaques
- Lesions are itchy / burning / painful
- common on extensor surfaces and scalp
- Auspitz sign” scratch and removal of scales causes capillary bleeding
- 50% have nail changes: pitting, onycholysis
- 5% have psoriatic arthropathy: symmetrical polyarthritis, asymmetrical oligoarthritis, lone distal interphalangeal disease, psoriatic spondylosis, arthritis mutilans
9
Q
Psoriasis management
A
General: avoid precipitating factors, emollients to reduce scales
Topical: localised and mild
- vitamin D analogues
- corticosteroids
- coal tar preparations
- dithranol
- retinoids
- keratolytics
Phototherapy: for extensive disease. UVB and photochemotherapy.
Oral: extensive and severe
- Methotrexate
- Retinoids
- Ciclosproin
- Biologicals: infliximab, etanercept, efazulimab
10
Q
Acne defintion
A
Inflammatory disease of the pilosebaceous follicle
11
Q
Acne aetiology
A
Hormonal: androgens
Contributing factors: increased sebum production, abnormal follicular keratinisation, bacterial colonisation (propionibacterium acnes), inflammation
12
Q
Acne risk factors
A
- Pressure / friction on skin
- Oily lotions
- Teenage
- Stress
13
Q
Acne presentation
A
Non-inflammatory lesions:
- Open comedones: blackheads
- Closed comedones: whiteheads
Inflammatory lesions:
- papules
- pustules
- nodules
- cysts
Commonly affects chest face and upper back
14
Q
Acne management
A
Topical: benzoyl peroxide, antibiotics, retinoids
Oral: antibiotics, anti-androgens in females, retinoids
15
Q
Rosacea definition
A
Chronic relapsing disease of facial skin characterised by recurrent episodes of facial flushing with persistent erythema, telangiectasia, papules and pustules.
16
Q
Rosacea aetiology
A
- Chronic acneiform disorder of facial pilosebaceous glands with increased reactivity of capillaries to head causing flushing and eventually telangiectasia
- Full mechanism unknown but altered immune response involved
- Medication associations: amiodarone, topical steroids, nasal steroids, vit B6/12
- Flushing caused by heat / temp change, alcohol, caffeine, spicy food, stress, sun, vasodilators
17
Q
Rosacea presentation
A
Symptoms:
- long history flushing
- progresses to constant flushing with obvious telangiectasia
- gritty eyes and facial oedema
Signs:
- skin not greasy, can be dry
- erythema and telangiectasia over forehead and chees
- nose / cheeks / forehead / chest / neck / ears affected
- prominent sebaceous glands
- nose may be enlarged / distorted - rhinphyma
- peri-orbital oedema
18
Q
Rosacea managment
A
General:
- avoid precipitating factors: products containing sodium lauryl sulfate and topical steroids
- facial massage to reduce oedema
- daily suncream application
Pharmacological:
- topical: metronidazole, azelaic acid, oral abx if papulopustular
- isotretinoin used for resistant cases
19
Q
Urticaria definition
A
Hives - itchy red rash resulting from swelling of superficial skin.
20
Q
Urticaria aetiology
A
Activation of skin mast cells, resulting in histamine release This causes capillaries to leak leading to swelling. Angio-oedema can also occur when deeper tissues are involved.
Triggers can be:
- allergies: foods, bites, stings, medication - NSAIDs / ACEi
- viral infection
- skin contact
- physical stimuli: rubbing pressure, temperature
21
Q
Urticaria presentation
A
- Typical lesion: central itchy white papule / plaque surrounded by erythematous flare. Vary in size and shape, can be accompanied by angioedema.
- Individual lesions transient - come and go within hours
- Classified as acute (<48h), chronic (> 6 weeks)
22
Q
Urticaria managment
A
- Identify and treat cause
- Non-sedating H1 antihistamines: cetirizine, loratadine, fexofenadine
- If ineffective, increase dose x4 or add another antihistamine
- Short course oral steroids may be indicated if severe
23
Q
Basal cell carcinoma definition
A
Slow growing locally invasive malignant tumour of epidermal keratinocytes
24
Q
Basal cell carcinoma aetiology
A
- Tumour infiltrates local tissues though slow irregular growth
- Morbidity from local tissue invasion and destruction
- Chronic sun exposure
25
Basal cell carcinoma risk factors
UV exposure
Male
Xeroderma pigmentosa, albinism
26
Basal cell carcinoma presentation
- Typical lesion: translucent / pearly papule with raised areas, telangiectasia, rolled edges and a central depression
- Rodent ulcer: indurated and ulcerated centre. Slow growing but spreads deep and destroys tissue.
27
Basal cell carcinoma investigation
Biopsy
28
Basal cell carcinoma managment
- Surgical excision + histological examination of tumour and margins
- Micrographic surgery if high risk recurrent
- Radiotherapy if surgery not appropriate
- Cryotherapy, curettage and cautery
29
Squamous cell carcinoma defintion
Locally invasive malignant tumour of epidermal keratinocytes with potential to metastasise.
30
Squamous cell carcinoma aetiology
Dysplastic cells which span full thickness of epidermis and have spread into dermis.
Precursor's:
-Actinic keratosis: diffuse dysplastic cells within epidermis
-Bowen's disease: dysplasia spanning full thickness of epidermis
31
Squamous cell carcinoma risk factors
- UV light
- Susceptibility to light: fair skin (FItzpatrick type I), blonde, red hair
- Chemical carcinogens
- HPV
- Ionising radiation
- Immunodeficiency
- Chronic inflammation
- Genetic conditions: xeroderma pigmentosum, albinism
32
Squamous cell carcinoma presentation
- Indurated nodular keratinising / crusted tumour that may ulcerte or present as an ulcer without evidence of keratinisation
- Non-healng ulcer or growth in sun-exposed areas.
- Clinical appearance: enlarging module with centre becoming nectroting and sloughing, developing into ulcer
- Slow growing with reddish skin plaque - bleeding may occur
- May give rise to local mets / spread to local lymph nodes
33
Squamous cell carcinoma management
- Complete surgical excision, send for histopathological examination
- Other options: curettage and cautery, cryotherapy, topical, photodynamic therapy, radiotherapy
34
Malignant melanoma definition
Malignant growth of melanocytes.
35
Malignant melanoma aetiology
- Damage to melanocytes found in basal layer of epidermis, by UV
- Once melanoma spreads to dermis, can spread thorugh lymphatic system to local lymph nodes or via blood stream
- Common mets: lung, brain, bone, liver, lymph
36
Malignant melanoma risk factors
- Naevi: 100+ 5-20x higher risk
- Sun exposure
- Type I skin
- Actinic keratosis
- High SES
37
Malignant melanoma presentation
```
A: asymmetry
B: border irregular
C: colour irregular - brown and black
D: diameter > 7mm
E: evolving
```
38
Malignant melanoma differentials
For any brown patch:
- benign naevi
- seborrheic keratosis
- melanoma
39
Malignant melanoma investigation
- Visual inspection with dermatoscope and removal for histology
- Diagnosis based on full-thickness biopsy
- Breslow thickness measure to determine malignant potential
40
Malignant melanoma management
- Surgical excision definitive treatment
- Radiotherapy useful
- Chemo if metastatic
41
Impetigo definition
Acute superficial bacterial infection most common in children
42
Impetigo aetiology
- Most commonly S. aureus, can be Strep pyogenes.
| - Non-bullous, bullous or ulcerated
43
Impetigo risk factors
- Immunosuppressed
- Summer
- Atopic eczema
- Scabies
- Skin trauma
44
Impetigo presentation
- Primarily affects exposed areas: face, hands
- Irregular crops or irritable superficial plaques with honey crusting
- Extend when healing to form annular or arcuate lesions
- Lymphadenopathy, fever, malaise
45
Impetigo management
- Wound hygiene
- Antibiotics to carrier sites to prevent recurrence
- Avoid contact with others
46
Cellulitis definition
Common bacterial infection of lower dermis / subcutaneous tissue
47
Cellulitis aetiology
S. pyogenes
S. aureus
P. aeruginosa
48
Cellulitis presentation
- Can affect any site but usually unilateral limb
- Localised area of painful, red, swollen skin
- Peau d'orange
- Blistering, erosions, ulceration, purpura
- Poorly demarcated borders
- Red lines streaking away represent progression of infection into lymphatic system
- Crepitus if anaerobic organism
- Systemic signs of infection
49
Cellulitis management
Uncomplicated: oral abx 5-10 days, symptomatic relief for pain and fluid loss
Complicated: systemic illness. Fluids, IV abx with oral switch when fever settles, cellulitis regresses and CRP reducces. O2.
Recurrent: avoid trauma, wear long sleeves, skin hygiene. Avoid blood tests in affected site. Keep swollen limbs elevated to aid lymphatic circulation.
50
Molluscum Contagiosum definition
Common skin infection caused by pox virus, transmitted by direct contact.
Most common in children < 10
51
Molluscum Contagiosum aetiology
Molluscum contagiosum mvirus. Spread by:
- direct contact
- indirect through contaminated objects
- auto-inoculation into site by scratching
- sexual
Incubation 2weeks - 6months
52
Molluscum Contagiosum presentation
- Clusters of small round papules 1-6mm, white / pink / brown. Umbilicated (central depression). Contains cheesy white material.
- Located in warm moist areas: axilla, knees, groin
- Papules in a row if from scratching
- Induce surrounding dermatitis
53
Molluscum Contagiosum management
- Usually self-limiting
- Physical: burst papules, cryotherapy, curettage and cautery, laser ablation
- Medical: antiseptics e.g. h2o2 cream, salicylic acid, topical abx
54
Seborrhoeic Keratosis definition
Common benign hyperkeratotic skin lesions associated with ageing.
55
Seborrhoeic Keratosis aetiology
Degenerative condition with UV role in causation. Oncogenic mutations. Full aetiology poorly understood.
56
Seborrhoeic Keratosis presentation
- Flat-topped lesions, 1mm-several cm with well circumscribed border
- Usually deeply pigmented - brown / black
- Surface pitted and irregular with visible keratin dots
- Multiple lesions may align along skin folds
- Usually asymptomatic - may become irritated, itchy or inflamed
57
Seborrhoeic Keratosis management
```
Surgical removal
Curettage and cautery
Laser
Shave biopsy
Chemical peel
```
58
Necrotising fasciitis
Life threatening infection involving any layer of deep soft tissue compartment - dermis, subcut, fascia, muscle
59
Necrotising fasciitis aetiology
- Wide spread necrosis
- Organism spread from subcut tissue along superficial and deep fascial planes
- Muscle usually spared
- Multi-bacterial symbiosis and synergy
- Common organisms: S. pyogenes, anaerobes + GN
60
Necrotising fasciitis presentation
- Patients systemically ill with disproportionately severe pain - only minor skin changes in initial stages
- Can affect anywhere but usually extremities, perineum or trunk
- Starts with localised pain swelling and oedema with infection poorly demarcated
- Systemic illness
- Develops into tense oedema, may be bullae, discoloured skin, crepitus due to subcut gas, pain may progress to anesthesia as nerves are destroyed, broad erythematous tract in skin
- Hypotension and shock
- Confusion, apathy
61
Necrotising fasciitis investigation
- Exploratory surgery: macroscopic features of grey necrotic tissue
- Bloods: increased WCC / CRP / CK / urea, decreased sodium
- Microbiology: cultures, wound swab, gram stain, fungal culture
62
Necrotising fasciitis mangement
- Early and aggressive wound debridement
- Broad spec high dose abx
- Close monitoring and supportive measures
- Nutritional support due to high protein and fluid loss
63
How does Lichen Planus normally present
```
6 P's
Planar (flat-topped)
Purple
Polygonal
Pruritic
Papules
Plaques
```
