ICA7&8 - Dermatology

Question 1

SCAM for describing skin lesions

Site and Distribution x4
Colour (x4) and Configuration(x4)
Associated Changes (surface features) x4
Morphology x12

Answer 1

1. ) Site and Distribution
   - generalised, flexural, extensor, photosensitive
2. ) Colour
   - erythematous, purpuric (purple, non-blanching)
   - brown or black suggests (hyper)pigmented
   - hypopigmented is total loss of colour
3. ) Configuration - shape or outline
   - discrete (well defined), confluent, linear, target
4. ) Surface Features
   - scale (built up keratin), crust (dried exudate)
   - excoriation (erosion from scratching), erosion/ulcer

5.) Morphology - form or structure

Question 2

9 morphological features of skin lesions

Macules and Patches
Papules and Plaques
Pustules, Vesicles and Bulla
Nodules 
Wheals

Answer 2

1. ) Macules and Patches - nonpalpable lesions
   - macules are <1cm and vary in pigmentation
   - patches are >1cm and are flush w/ surrounding skin
2. ) Papules and Plaques - palpable lesions
   - papules are discrete and <1cm, isolated or grouped
   - plaques are >1cm, may be formed by papules
3. ) Pustules, Vesicles and Bulla
   - are all small circumscribed skin papules
   - pustules contain purulent fluid
   - vesicles contain clear serous or haemorrhagic fluid
   - bulla are large (>1cm) vesicles

4.) Nodules - palpable, solid or cystic, discrete lesions measuring 1-2cm in diameter

5. ) Wheals - irregular, elevated, oedmatous skin
   - may be erythematous or paler than surrounding skin

Question 3

Hair (x4) and Nail (x4) findings

Answer 3

1. ) Hair
   - alopecia (patchy or diffuse), hypertrichosis, hirsuitism
2. ) Nail
   - koilonychia, onycholysis, pitting, clubbing

Question 4

4 features of atopic eczema

Description x8
Types x2
Diagnosis
Treatment x2

Answer 4

1. ) Description - generalised symmetrical rash
   - erythematous, non-discrete, scaly, erosions, patches

2.) Types - can be acute or chronic and can also be endogenous or exogenous

3. ) Diagnosis - symptoms + FH of atopy
   - description + pruritis
4. ) Treatment
   - avoid exacerbating factors
   - non-perfumed emollient, topical steroids

Question 5

4 features of psoriasis

Descrption x5
Cause
Complications x2
Treatment x4

Answer 5

1. ) Description - plaques on extensor surafces
   - discrete, scaly, w/ associated nail pitting
2. ) Cause - overactive maturation of keratinocytes
   - worsened by stress, infections, cold weather
3. ) Complications
   - psoriatic arthritis, nail pitting
4. ) Treatment
   - steroid creams, vitamin-D3 analogues
   - UV light therapy and immunosuppressant therapy

Question 6

3 features of urticaria (hives)

Description x8
Cause
Treatment

Answer 6

1. ) Description - generalised symmetrical rash
   - erythematous, discrete, papules and plaques
   - if transient (<24h), they are called wheals
2. ) Cause - allergies or unknown reason
   - mast cell degranulation and histamine release leads to increased capillary permeability and leakage of fluid
3. ) Treatment
   - remove underlying cause (e.g. drug related)
   - high-dose anti-histamines, oral steroids (acute course)

Question 8

4 features of shingles

Description x8
Cause
Complications x4
Treatment

Answer 8

1. ) Description - dermatomal rash
   - papules, vesicles, bulla, crust and erosion
   - associated with burning pain
2. ) Cause - herpes zoster infection
   - re-activation of virus (chicken pox, varicella) which has remained dormant in a sensory root ganglion
3. ) Complications
   - neuralgic pain, secondary bacterial infection
   - paralysis, corneal ulcers (if CNVa affected)
4. ) Treatment - antivirals and analgesics
   - systemic acyclovir

Question 9

4 features of erythroderma

Description/Signs x5
Causes x4
Symptoms x4
Complications x5

Answer 9

1. ) Description/Signs - widespread (90% of body) rash
   - generalised, erythematous, exfoliative, scaly
2. ) Causes
   - psoriasis, eczema, drugs, cutaneous T cell lymphoma
3. ) Symptoms
   - pruritus, fatigue, anorexia, feeling cold
4. ) Complications - ‘total skin failure’
   - hypothermia: reduced thermoregulation
   - infection: loss of protective barrier
   - renal failure: due to insensible losses
   - HFpEF: due to dilated skin vessels
   - protein malnutrition: high turnover of skin

Question 9

4 other common skin conditions

Acne Vulgaris
Molluscum Contagiosium
Tinea Capis
Drug Exanthem

Answer 9

1. ) Acne Vulgaris - inflammation of pilosebaceous units
   - generalised maculopapular vesicles, pustules and comedones w/ crusting and excoriation
   - can be affected by diet, stress and infections
   - treat w/ lifestyle, antibiotics, hormonal therapy
2. ) Molluscum Contagiosum - pox virus infection
   - localised, discrete, shiny dome-shaped papules
   - most self resolve within 6-9 months
3. ) Tinea Capis - tinea (fungal) infection
   - body: solitary, discrete, erythema, scaly annular plaque
   - scalp: accompanying hair loss (patch of alopecia)
   - treatment can be topical creams or systemic drugs
4. ) Drug Exanthem - allergic drug reaction (few days)
   - generalised, erythematous, macular, papular,rash
   - morbilliform (macular-papular) rash)