Derm

Question 1

Epidemiology of impetigo

Answer 1

Common < 4 years old

Question 2

Pathophysiology of impetigo

Answer 2

Primarily S.aureus or S.pyogenes

Inoculated into skin and lesions occur 7-14 days later

Question 3

Clinical features of impetigo

Answer 3

Non-bullous
- multiple vesicles or pustules appear on exposed regions of skin
- easily rupture leaving honey coloured crust
Bullous
- most common in neonates
- thin, friable bullae appear and rupture leaving erythematous base with scaly collarette

Question 4

Mx of impetigo

Answer 4

Topical antibiotic
- fusidic acid
Gentle cleaning of lesions
Topical antihistamine is pruritic lesions

Question 5

Pathophysiology of atopic eczema

Answer 5

Chronic inflammatory condition of the skin
Sensitising event
Immune system mounts Th2-mediated response to irritants/allergens
Overexpression of Il-4, Il-5 and Il-13
Causes an acutely pruritic lesion
Can become chronic and lichenified over time

Question 6

Epidemiology of atopic eczema

Answer 6

20% of children have to some degree

Most present before 5 years of age

Question 7

Clinical features of atopic eczema

Answer 7

Distribution
- infants - cheeks
- mobile infant - cheeks and extensor surfaces
- older children - flexures, wrists and ankles
Pruritic, poorly defined erythematous lesion a/w dry skin
Pustules or crusting indicates secondary bacterial infection

Question 8

Mx of atopic eczema

Answer 8

Identify triggers
Consistent application of emollient to whole body
- replace usual soap too 
Mild
- mild potency corticosteriods
Moderate
- moderate potency corticosteriods
- topical calcineurin inhibitors - tacrolimus
Severe
- high potency topical corticosteriods
- topical calcineurin inhibitors
- phototherapy
- systemic therapy - derm referral