Dermatology Flashcards
Which pathogen causes eczema herpeticum?
Herpes simplex virus type 1. Uncommonly eczema herpeticum can be caused by Coxsackie A16.
What would be the next step to treat psoriasis after eight weeks of using a potent corticosteroid and a vitamin D analogue once daily and no improvement?
Increase the frequency of the vitamin D analogue while stopping the corticosteroid
If treatment is needed for acne in pregnancy, what is the antibiotic of choice?
Erythromycin. Avoid retinoids or doxycycline or lymecycline
First line treatment for capillary haemangiomas requiring intervention? What are alternative options?
Propanolol
Alternatively, laser therapy or systemic steroids can be tried.
When would suspected BCC be an urgent referral as opposed o usual non-urgent referral?
If in the ‘T’ zone (i.e. around eyes & nose)
First-line treatment for scalp psoriasis?
Scalp psoriasis - first-line treatment is topical potent corticosteroids. e.g. betamethasone valerate
When and what would topical treatment vs oral be suitable for onychomycosis
Oral terbinafine is first line treatment
Topical amorolfine could be considered for mild to moderate distal and lateral subungual onychomycosis affecting fewer than three nails.
Describe the differences between lichen planus and psoriasis
- Distribution: Lichen planus often affects the flexor surfaces of the wrists, legs, trunk, and oral mucosa. Psoriasis typically involves extensor surfaces like elbows and knees, scalp and nails but can be more widespread.
- Lesions: The primary lesion in lichen planus is a flat-topped, polygonal, violaceous papule often with fine white lines (Wickham’s striae) visible on their surface. Psoriatic lesions are usually well-demarcated erythematous plaques with silvery scales.
- Nail changes: In lichen planus, nail changes include ridging and thinning of the nails which may lead to pterygium formation or even loss of the nail plate entirely. Psoriatic nail disease presents as pitting, onycholysis (separation of the nail from the nail bed), or an ‘oil drop’ discolouration.
- Koebner phenomenon: Both conditions show this phenomenon where new lesions occur at sites of skin trauma; however it is more commonly associated with psoriasis.
- Oral involvement: Oral involvement is common in lichen planus but rare in psoriasis unless it is part of a more severe systemic disease manifestation.
What is the treatment of impetigo if its MRSA?
What is the second line management if hydrogen peroxide doesn’t work?
topical mupirocin (or if fusidic acid resistance is suspected)
Second line if fusidic acid
Most common side effect of isotretinoin?
Dry skin
What medicine is safe for long-term use in psoriasis?
Calcipotriol
First line management of venous ulceration
Compression bandage if ABPI normal (0.8-1.3)
When should re-treatment of scabies be considered?
Retreatment should only be considered if new burrows or rashes appear, or if living mites are found upon examination.
Itching can persist for up to 6 weeks after successful treatment due to a delayed hypersensitivity reaction to the mites, even if all the mites have been killed.
What features would you look for to refer to dermatology for systemic retinoid (isotertinoin) treatment for acne?
Not responded to a 3-month trial of treatment with an oral antibiotic.
AND
Moderate-severe features such as scarring, nodulocystic acne, severe psychological distress
How does the treatment to an acute flare of flexor psoriasis differ to extensor?
Flexural Psoriasis: Requires gentler treatments due to the sensitive nature of intertriginous skin. Combination therapy with antifungals is common.
Extensor Psoriasis: More robust treatments, such as higher-potency steroids and vitamin D, are often needed to penetrate thick plaques.
