Derm Flashcards
Explain the pathophys of acne
- Seborrhea (inc sebum production)
- Narrowed follicle blocks sebum - comedo formation
- Sebum stagnates and P. Acnes colonises follicle
- Leading to inflammation of pilosebaceous unit
How does acne present
- Open and closed comedones (dilated sebaceous follicle)
- Papules and pustules
What is the treatment for acne?
- topical benzoyl peroxide or retinoid
- Add topical antibiotic
- Oral antibiotic - tetracyclines (Contraindicated in preg)
- COCP for women
- Oral isotretinoin
What must be given alongside oral antibiotics for acne to prevent antibiotic resistance?
topical retinoid/benzoyl peroxide
what might occur as a complication of long term Abx use for acne
gram neg folliculitis
how is gram negative folliculitis treated
high dose oral trimethoprim
which Abx for acne in pregnancy
erythromycin
briefly explain the pathophys of eczema
- loss of function mutations in filaggrin
- defects in skin barrier
- allows irritants, allergens and microbes to enter
- immune response triggered, leading to inflammation
how does eczema present
dry erythematous itchy skin, poorly defined rash
particularly on flexor surfaces
how is eczema managed
- avoid irritants
- emollients
- topical steroids - weakest for shortest period required to calm flare down
- wet wrapping
- sedative antihistamines if itchy
- immunosuppressants - tacrolimus, ciclosporin azathioprine
what are the side effects of topical steroids
- thin skin, striae, bruising, more prone to flares
- acne
- telangiectasia
list in order of potency topical steroids
weak: hydrocortisone
moderate: eumovate (clobetasone butyrate)
potent: betnovate (betamethasone)
very potent: dermovate (clobetasol propionate)
which organism most commonly causes infection in eczema and how is it treated
s. aureus, oral fluclox or topical fucidic acid
which organism causes eczema herpeticum
herpes simplex virus (HSV1)
what are the symptoms of eczema herpeticum
painful widespread vesicular rash (may contain pus) fever lethargy irritability reduced oral intake lymphadenopathy
describe the rash associated with eczema herpeticum
vesicular rash, vesicles may contain pus
vesicles leave behind monomorphic punched out lesions with a red base (ulcerated)
how is diagnosis of eczema herpeticum confirmed
viral swabs - treat based on clinical picture, dont wait for results to come back
how is eczema herpeticum treated
mild/moderate - oral aciclovir
severe - admit for IV aciclovir
children should be admitted
what is a complication of eczema herpeticum
bacterial superinfection
scarring from blisters
herpetic keratitis - can lead to blindness
What is BCC also known as
rodent ulcers
Do BCC metastasise
extremely rare
where do BCC usually present
sun exposed areas, head and neck
how do BCC usually present
pearly, flesh-coloured papule with telangiectasia, which may ulcerate and leave a central “crater”
How is BCC managed
surgical removal curettage and cautery cryotherapy topical cream - imiquimod and fluorouracil radiotherapy
what are the RFs for BCC
exposure to UV light lighter skin radiotherapy immunodeficiency long term exposure to arsenic
what is the pathophys of cellulitis
inflammation of skin and subcutaneous tissues due to streptococcus pyogenes or s. aureus
how does cellulitis present
commonly presents on shins
erythema, swelling, warmth, pain
may be systemic signs of inflammation - fever
what Abx for cellulitis
fluclox
if allergic, clarithromycin or erythromycin in pregnancy
what treatment of severe cellulitis
co-amox, clindamycin, cefuroxime, ceftriaxone
what are the two types of contact dermatitis
allergic
irritant
how is contact dermatitis investigated
patch testing
how does contact dermatitis present
red rash
wheals/blisters/urticaria
itchy burning skin
what type of hypersensitivity reaction is contact dermatitis?
type IV
give an example of allergic contact dermatitis and its treatment
following hair dye, scalp line inflamed with acute weeping eczema, treat with potent topical steroids
what can cause irritant contact dermatitis
due to detergents
