d e r m a t o l o g y Flashcards
what is acne vulgaris
inflammation of the pilosebacious follicle - increased production of sebum, trapping keratin and blockage of pilosebaceous units leading to swelling and inflammation
why is acne worsened by puberty
androgenic hormones increase production of sebum
swollen and inflammed skin units are called
comodones
how is acne vulgaris managed
no tx if mild
topical benzoyl peroxide = reduces inflammation + unblocks skin and toxic to bacteria
topical retinoids - slow sebum production (need effective contraceptive)
topical abx e.g clindamycin prescribed with benzoyl peroxide to reduce bacterial resistance
oral abx - lymecycline
OCP can help F stabilise hormone and slow production of sebum = Dianatte/ Co cyprindiol
retinoids require
follow up and monitoring + reliable contraception
retinoids are highly teratogenic
which OCP is most effective for acne
co-cyprindiol/ dianette
anti androgenic effects
but has higher thromboembolism so stop treatment as soon as acne is controlled - not prescribed long term
oral retinoids are used in
severe acne
last line option
isotretinoin but teratogenic
what is eczema
chronic atopic condition caused by defects in the normal continuity of the skin barrier, leading to inflammation in the skin.
how does eczema present
dry red itchy sore patches over flexor surfaces
face and neck
flare - remitting and relapsing
how is eczema managed
mantainence = emollients
avoid triggers - certain washing powders, cleaning powders, stress
flares = thicker emollients + treat viral or bacterial infections
what is the rule for emollient use
general rule is to use emollients that are as thick as tolerated and required to maintain the eczema.
give examples of thin emollients
E45
Aveeno cream
Diprobase cream
Oilatum cream
give examples of thick greasy emollients
50:50 ointment (50% liquid paraffin)
Hydromol ointment
Diprobase ointment
describe the steroid ladder in eczema
mild = hydrocortisone
moderate = eumovate
potent = betnovate
very potent = dermovate
treatment of bacterial infection in eczema
staph aureus
oral flucloxacillin
SE of steroid use in eczema
an lead to thinning of the skin, which in turn make the skin more prone to flares, bruising, tearing, stretch marks, telangiectasia. + systemic absorption of steroid
what is psoriasis
chronic immune condition that leads to skin changes are caused by the rapid generation of new skin cells, resulting in an abnormal buildup and thickening of the skin in those areas.
describe the management of psoriasis
- Topical steroids
- Topical vitamin D analogues (calcipotriol)
- Topical dithranol
- Topical calcineurin inhibitors (tacrolimus) are usually only used in adults
- Phototherapy with narrow band ultraviolet B light
what is urticaria
hives = associated with patchy erythematous rash
associated with angioedema and flushing
acute vs chronic
describe the pathophysiology of urticaria
release of histamine and other pro-inflammatory chemicals by mast cells in the skin. This may be part of an allergic reaction in acute urticaria or an autoimmune reaction in chronic idiopathic urticaria
what are the causes of urticaria
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
triggers of chronic urticaria
Sunlight Temperature change Exercise Strong emotions Hot or cold weather Pressure
management of urticaria
antihistamines - fexofenadine
oral steroids for short term severe flares
what are the ddx for skin cancers
- bcc
- scc
- malignant melanoma
what are the risk factors of bcc
uv exposure hx of severe sunburn in childhood skin type i = always burns, never tans increasing age immunosupression male sex
describe the presentation of bcc
nodular superficial cystic morphoeic/sclerosing keratin and pigmented
most common over head and neck
describe the management of bcc
surgical exicision - allows for histological examination
radiotherapy when surgery is not appropriate
what is scc
invasive malignant tumour of epidermal keratinocytes
rx of scc
uv exposure hx of frequent or severe sunburn skin type i = always burns, never tans increasing age male immunosuppression
management of scc
surgical excision - treatment of choice
radiography if non-resectable
chemotherapy - for metastatic disease
what is a malignant melanoma
invasive malignant tumpor or epidermal melanocytes
with potential to metastasise
what are the risk factors of melanoma
excessive uv exposure
skin type i - always burns never tans
hex in first degree relative or previous hx of melanoma
describe the abcde of melanoma presentation
asymmetrical shape border irregularity colour irregularity diameter greater than 7mm evolution of lesion = change in size or shape symptoms - bleeding and itching
more common in legs in f and trunk in men
describe the management of melanoma
surgical excision is definitive treatment
chemo for metastatic disease
