derm conditions

Question 1

acne 
cause, risk
symptoms
diagnose 
treat

Answer 1

Cause unknown - but increased sebum production during puberty plus hyperkeratosis leads to blocking of hair follicle - still open to surface = open comedones. This creates an anaerobic environment, in which commensal bacteria propionibacterium acnes proliferates. Immune response to the bacterial overgrowth results in inflammation - closed comedones.
Genetics, polycystic ovaries, psychological stress, products, behaviours, puberty.
Diagnose clinically, skin swabs for M&C, hormonal tests
Treat:
mild - benzyl peroxide cream, topical antibiotics: clindamycin gel
Severe: above + oral doxycycline, hormonal co-cyprinidol

Question 2

Exczema - define?
types
symptoms
diagnose
treat

Answer 2

Inflammatory skin disease where damaged filaggrin (skin barrier protein) results in thinning of stratum corneum. Exogenous allergens are able to invade, causing inflammation.
1. endogenous: atopic exczema, due to hypersensitivity
2. exogenous: contact dermatitis(chemicals, sweat, abrasives)
Diagnose: for atopic, 80% have high serum IgE
Clinical itchy skin condition, + dry skin/skin creases/history(fam/personal), childhood onset
Treat: education and explannation
Emollient: E45 3-4 times a day to replace lost NMF
Topical corticosteroids hydrocortisone

Question 3

Psoriasis - define?
Symptoms
Risk
Treat

Answer 3

Chronic, inflammatory skin disease. Caused by hyperproliferation of keratinocytes and inflammatory cell infiltration, leads to thickened plaques. Can be tought of as opposite to excema as skin thickens
There are 4 types with different characteristic skin appearance/area affected. Chronic plaque psoriasis is most common - pink scaly plaques, disc shaped, on elbows/knee/scalp, may have nail pitting/oncholysis.
Risk:
Infection with group A strep (–> guttate psoriasis)
Drugs, UV, alcohol, stress, family hist.
Treat:
emollient - E45
Topical corticosteroids - hydrocortisone
Vit D analogue: calcipotrol, not for face

DMARD methotrexate if extensive

Question 4

Skin cancer:
3 types and definitions

appearance

Answer 4

1. Basal cell carcinoma (80% of all): malignant non-melanoma, locally destructive, locally invasive, slow growing. Looks pearly, shiny nodule, bleeds following minor trauma, may ulcerate.
2. Squamous cell carcinoma: locally invasive, malignant tumour of keratinocytes. More aggressive than BCC but mets still rare .Keratotic, ill defined nodule
3. Malignant melanoma: malignant tumour of melanocytes. Dark, irreg border, large, changes

Question 5

Malignant melanoma
Risk
Criteria for diagnosis

treatment

Answer 5

Malignant tumour of melanocytes
Risk: red hair, freckles, UV light, heavy drinking
Usually on chest/back (men), lower legs (women)
A - asymmetrical
B - border irregularity
C - colour changes
D - diameter > 6mm
E - elevation/evolution
Treat: surgical excision
30-50% metastasise: commonly to lungs, liver, CNS - removal lymph nodes, radiotherapy, immunotherapy, chemo