Dermatology Flashcards
causes of acanothis nigricans
- type 2 diabetes mellitus
- gastrointestinal cancer
- obesity
- polycystic ovarian syndrome
- acromegaly
- Cushing’s disease
- hypothyroidism
- Prader-Willi syndrome
- drugs
- combined oral contraceptive pill
- nicotinic acid
what is the common bacterium that causes acne
Propionibacterium acnes
what is the first-line management of acne
a single topical therapy containing a retinoid and benzoyl peroxide
what is the second-line treatment of acne vulgaris
- after trialling a topical treatment containing a retinoid and benzoyl peroxide
- try a combination therapy of a topical antibiotic, topical retinoid and benzoyl peroxide
what is the third line treatment for acne vulgaris
- if topical treatment containing antibiotic, retinoid and benzoyl peroxide doesn’t work then use:
- oral tetracycline such as doxycycline
- if pregnant: erythromycin
- COCP is an alternative
- both oral abx and COCP should be co-prescribed with a topical retinoid
- oral abx should be used for a maximum of months
if oral abx/COCP doesn’t work for acne what treatment should you start
- oral isotretinoin
- should only be prescribed under specialist supervision
- pregnancy is a contraindication so they must be on adequate contraception
what is a contraindication to topical or oral retinoid treatment
pregnancy
try oral erythromycin for months with topical benzoyl peroxide
what is actinic keratoses and what is the management
a common premalignant skin lesion that develops as a consequence of chronic sun exposure
treatment is a 2-3 weeks course of fluorouracil cream - this will cause inflammation that may require hydrocortisone to settle
what do you get at the edges of a lesion of alopecia
small, broken, ‘exclamation mark’ hairs
what is the prognosis of alopecia areata
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually
what is the treatment of alopecia areata
- since 50% will have their hair grow back in a year and 80% will have it grow back at some point, careful counselling is often all that is needed
- other treatment options include
- topical corticosteroids
- phototherapy
two examples of non-sedating antihistamines
- loratidine
- cetirizine
what is an example of a sedating antihistamine
- chlorpheniramine
apart from drowsiness, what other side effect do sedating antihistamines cause
antimuscarinic properties (e.g. urinary retention, dry mouth)
what is the treatment for athlete’s foot
topical imidazole
what is the most common type of cancer in the western world?
BCC
what are the features of BCC
- sun-exposed sites, especially the head and neck
- pearly, flesh-coloured papule with telangiectasia
- may later ulcerate leaving a central ‘crater’
what type of referral for BCC
routine since metastases are extremely rare
what is bowen’s disease and what is the management
- pre-cancerous skin condition that can lead to SCC
- typically in sun exposed areas on the elderly
- management is topical 5-fluorouracil
- twice daily for 4 weeks
- often results in significant inflammation/erythema. Topical hydrocortisone to control this
what is bullous pemphigoid
autoimmune condition resulting in sub-epidermal blistering
what is the management of bullous pemphigoid
- referral to a dermatologist for biopsy and confirmation of diagnosis
- oral corticosteroids are the mainstay of treatment
how do you assess the extent of a burn
- Wallace’s Rule of Nines: head + neck = 9%, each arm = 9%, each anterior part of leg = 9%, each posterior part of leg = 9%, anterior chest = 9%, posterior chest = 9%, anterior abdomen = 9%, posterior abdomen = 9%
what is dermatitis herpetiformis
autoimmune blistering skin disorder associated with coeliac disease. It is caused by deposition of IgA in the dermis.
what is a dermatofibroma
it is a common benign skin lesion
like a little bump
often follows skin injury
overlying skin dimples when pinched