Dermatology Flashcards
What is systemic mastocytosis?
Systemic mastocytosis results from a neoplastic proliferation of mast cells
What are the features of systemic mastocytosis?
urticaria pigmentosa - produces a wheal on rubbing (Darier’s sign)
flushing
abdominal pain
monocytosis on the blood film
How do you diagnosis systemic mastocytosis?
raised serum tryptase levels
urinary histamine
What is the difference between hirsutism and hypertrichosis?
Hirsutism is often used to describe androgen-dependent hair growth in women, with hypertrichosis being used for androgen-independent hair growth
What are the causes of hirsutism?
PCOS
Cushing’s syndrome
congenital adrenal hyperplasia
androgen therapy
obesity: thought to be due to insulin resistance
adrenal tumour
androgen secreting ovarian tumour
drugs: phenytoin, corticosteroids
What is the test for assessing hirsutism?
Ferriman-Gallwey scoring system: 9 body areas are assigned a score of 0 - 4, a score > 15 is considered to indicate moderate or severe hirsutism
How do you manage hirsutism?
advise weight loss if overweight
cosmetic techniques such as waxing/bleaching - not available on the NHS
consider using combined oral contraceptive pills such as co-cyprindiol (Dianette) or ethinylestradiol and drospirenone (Yasmin). Co-cyprindiol should not be used long-term due to the increased risk of venous thromboembolism
facial hirsutism: topical eflornithine - contraindicated in pregnancy and breast-feeding
What are the causes of hypertrichosis?
drugs: minoxidil, ciclosporin, diazoxide
congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
porphyria cutanea tarda
anorexia nervosa
What are the features of lichen planus?
itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of arms
rash often polygonal in shape, with a ‘white-lines’ pattern on the surface (Wickham’s striae)
Koebner phenomenon may be seen (new skin lesions appearing at the site of trauma)
oral involvement in around 50% of patients: typically a white-lace pattern on the buccal mucosa
nails: thinning of nail plate, longitudinal ridging
What is the diagnosis?
Lichen planus
What is the diagnosis?
Lichen planus
What is the diagnosis?
Lichen planus
What is the diagnosis?
Lichen planus with oral involvement
What is the diagnosis?
Lichen planus
What is the management of chronic plaque psoriasis?
NICE recommend a step-wise approach for chronic plaque psoriasis
regular emollients may help to reduce scale loss and reduce pruritus
first-line: NICE recommend:
a potent corticosteroid applied once daily plus vitamin D analogue applied once daily
should be applied separately, one in the morning and the other in the evening)
for up to 4 weeks as initial treatment
second-line: if no improvement after 8 weeks then offer:
a vitamin D analogue twice daily
third-line: if no improvement after 8-12 weeks then offer either:
a potent corticosteroid applied twice daily for up to 4 weeks, or
a coal tar preparation applied once or twice daily
short-acting dithranol can also be used
What is the secondary care management of psoriasis?
-Phototherapy
narrowband ultraviolet B light is now the treatment of choice. If possible this should be given 3 times a week
photochemotherapy is also used - psoralen + ultraviolet A light (PUVA)
adverse effects: skin ageing, squamous cell cancer (not melanoma)
-Systemic therapy
oral methotrexate is used first-line. It is particularly useful if there is associated joint disease
ciclosporin
systemic retinoids
biological agents: infliximab, etanercept and adalimumab
ustekinumab (IL-12 and IL-23 blocker) is showing promise in early trials
What is the management of scalp psoriasis?
NICE recommend the use of potent topical corticosteroids used once daily for 4 weeks
if no improvement after 4 weeks then either use a different formulation of the potent corticosteroid (for example, a shampoo or mousse) and/or a topical agents to remove adherent scale (for example, agents containing salicylic acid, emollients and oils) before application of the potent corticosteroid
What is the management of flexural psoriasis?
NICE recommend offering a mild or moderate potency corticosteroid applied once or twice daily for a maximum of 2 weeks
What is seborrhoeic dermatitis?
Seborrhoeic dermatitis in adults is a chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur (formerly known as Pityrosporum ovale). It is common, affecting around 2% of the general population.
What are the features of seborrhoeic dermatitis?
eczematous lesions on the sebum-rich areas: scalp (may cause dandruff), periorbital, auricular and nasolabial folds
otitis externa and blepharitis may develop
Which conditions are associated with seborrhoeic dermatitis?
HIV
Parkinson’s disease
What is the management of scalp seborrhoeic dermatitis?
the first-line treatment is ketoconazole 2% shampoo
over the counter preparations containing zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) may be used if ketoconazole is not appropriate or acceptable to the person
selenium sulphide and topical corticosteroid may also be useful
What is the management of face seborrhoeic dermatitis?
topical antifungals: e.g. ketoconazole
topical steroids: best used for short periods
difficult to treat - recurrences are common
What is actinic keratosis?
Actinic, or solar, keratoses (AK) is a common premalignant skin lesion that develops as a consequence of chronic sun exposure
What are the features of actinic keratosis?
small, crusty or scaly, lesions
may be pink, red, brown or the same colour as the skin
typically on sun-exposed areas e.g. temples of head
multiple lesions may be present
What is the diagnosis?
Actinic keratosis
How do you manage actinic keratosis?
prevention of further risk: e.g. sun avoidance, sun cream
fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed - sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
topical imiquimod: trials have shown good efficacy
cryotherapy
curettage and cautery
What is Darier sign?
When a lesion is scratched or rubbed, histamine is released producing a swollen, pruritic wheal similar to urticaria
What is a niacin (Vitamin B3) deficiency called?
Pellagra
What are the features of Pellagra?
3D’s
-Dementia
-Dermatitis
-Diarrhoea
(Death if untreated)
What are the causes of Pellagra?
Alcohol excess
Isoniazid therapy
What are the skin disorders of pregnancy?
- Atopic eruption of pregnancy
- Polymorphic eruption of pregnancy
- Pemphigoid getationis
What are the features of atopic eruption of pregnancy?
is the commonest skin disorder found in pregnancy
it typically presents as an eczematous, itchy red rash.
no specific treatment is needed
What are the features of polymorphic eruption of pregnancy?
pruritic condition associated with last trimester
lesions often first appear in abdominal striae
management depends on severity: emollients, mild potency topical steroids and oral steroids may be used
What is the diagnosis?
Polymorphic eruption of pregnancy
What is the diagnosis?
Polymorphic eruption of pregnancy
What is the diagnosis?
Polymorphic eruption of pregnancy
What are the features of pemphigoid gestationis?
pruritic blistering lesions
often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
oral corticosteroids are usually required
What is the diagnosis?
Pemphigoid gestationis
What is the diagnosis?
Pemphigoid gestationis
