Derm 2 Flashcards
Pyoderma gangrenosum
- What is seen on biopsy?
- How is it managed?
- infiltrated neutrophils
2. oral steroids
due to risk of rapid progression
Dermatitis herpetiformis
- What is seen on biopsy?
- Other than gluten free diet what can be given?
- IgA deposition
2. dapsone
Fungal nail infections
- What is the most common cause?
- What is often the appearance of the nail?
- What investigation is done?
- How is it managed?
- trichophyton rubrum (90%)
- thickened, rough, opaque
- nail clippings / scrapping for culture
- oral turbinafine
- > 6 weeks - 3 months if finger nail
- > 3-6 months if toe nail
if candida is the cause then topical anti fungal or if severe oral itraconazole can be given
Impetigo
How is it managed regarding:
- limited disease
- extensive disease
- school exclusion
- hydrogen peroxide cream or topical fusidic acid
- > topical mupirocin if resistant - oral flucloxacillin
(erythromycin if pen. allergic) - > 48hrs after initiating ABx or wait until after lesions have healed
Molluscum contagiosum
- a) What causes it?
b) Who is it most common in? - What lesions are seen?
- How is it managed?
- a) molluschi contagiosum virus
b) children aged 1-4
2. “pink pearly papules” with central umbilicus
- avoid sharing towels and clothes
- only treat symptoms (e.g. topical corticosteroid for itch)
Pityriasis rosea
- What causes it?
- What CFs are seen?
- How is it managed?
- herpes hominis virus 7
- herald patch followed by smaller erythematous scaly patches
- self-limiting - should disappear after
Scabies
- What clinical features are seen?
- How is it managed?
- intense itch
- linear burrows on sides of fingers, interdigital web spaces and flexure surfaces of wrist
- 1st line: permethrin
2nd line: malathion
apply and leave for 8-12 hours (24 hours if malathion) before washing off and repeat again in 7 days
treat everyone in household, wash all laundry (towels etc) on first day of treatment
Other than pre-malignant lesions (actinic keratoses + Bowen’s) and sunlight exposure what are the RFs for SCC?
- smoking
- immunosuppression
- long standing leg ulcer (majorlin’s ulcer: malignancy arising from previously injured skin)
Actinic Keratoses
- What is seen?
- How can they be managed?
- small crusty scaly lesions on sun damaged skin
- flourouracil cream for 2-3 weeks +/- hydrocortisone after to reduce inflammation
topical diclofenac can be used for very mild lesions
- curettage + cautery
- cryotherapy
What clinical features are seen in hereditary haemorrhagic telangiectasia?
- recurrent epistaxis
- telangiectases: possibly lips, oral cavity, fingers, nose
- visceral lesions: for example gastrointestinal telangiectasia, pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM
- family history: a first-degree relative with HHT
What can be given for hirsutism?
- COCP
- topical eflornithine for face (but contraindicated in pregnancy)
Lichen sclerosus
- What CFs are seen?
- How is it managed?
- What is the patient at an increased risk of?
- itchy, white plaques on genitalia
- most commonly affects older women
+/- painful intercourse or urination
- topical steroids + emollients
- vulval cancer
- What drugs can cause toxic epidermal necrolysis?
2. How is it managed?
1.
- phenytoin
- sulphonamides
- allopurinol
- penicillins
- carbamazepine
- NSAIDs
- IV immunoglobulins
Bullous pemphigoid v pemphigus vulgaris
- How can they be differentiated?
- What are their pathophysiologies and hence what is seen on biopsy?
- How are they treated?
- bullous pemphigoid mucosal involvement less likely whereas pemphigus vulgaris likely to present with mucosal involvement (50-70% mouth ulcers)
- bullous pemphigoid more likely to have itch and have intact blisters
- bullous pemphigoid: IgG and C3 deposited at the dermo-epidermal junction
-> hence immunofluorescence shows linear band
pemphigus vulgaris: IgG invasion of desmosomes (glue holding epidermis together)
-> hence immunfluoresence shows chicken-wire appearance throughout epidermis
- oral / topical steroids
