Acne, eczema, psoriasis, molluscum Flashcards
(38 cards)
Describe the pathophysiology of acne
Follicular epidermal hyperproliferation = KERATIN PLUG causes obstruction of the pilosebaceous = follicle colonisation by anaerobic Propionibacterium acnes = inflammation
What are the 2 types of comedone?
o Open top: blackhead
o Closed top: whitehead
What are the features of acne?
Comedones Papules Pustules Nodules Cysts Scars: ice-pick, hypertrophic (keloid)
What is drug-induced acne and give e.g. of a drug?
Monomorphic
- get pustules in steroid use
What is acne fulimans?
Severe + systemic upset
Hospital admission required
Responds to oral steroids
Classify acne
1- Mild: open + closed comedones +/- sparse inflammatory lesions
2- Moderate: widespread non-inflammatory lesions + many papules, pustules
3- Severe: extensive inflammatory lesions +/- nodules, pitting, scarring
What is the step-up Mx of acne?
Single topical therapy: Topical retinoid, benzoyl peroxide
Topical combo therapy: Topical Abx, benzoyl peroxide, topical retinoid
Oral abx (max 3m): Tetracyclines, erythromycin
COCP: Alternative to oral abx
Oral isotretinoin (Roaccutane): Is a retinoid Only under specialist supervision CI to topical + oral retinoid = PREGNANCY
Give 3 e.g. of oal abx used for acne and when should they be avoided?
Tetracyclines: lymecycline, oxytetracycline, doxycycline
Avoid in PREGNANT/BREASTFEEDING + <12y
Which oral abx for acne are safe in pregnancy?
Erythromycin
What is one complication of long-term abx use in acne?
Gram -ve folliculitis
What should you prescribe for gram -ve folliculitis?
High-dose oral trimethoprim
What is cause of eczema?
Atopic
What gene is involved in eczema?
Filaggrin gene mutation
Primary defect in skin barrier
Immunological changes secondary to enhanced antigen penetration through a deficient epidermal layer
Name some triggers for an eczema flare-up
Soap/ detergents Overheating Rough clothing Skin infection Pets Aeroallergens (pollen) Food House-dust mites Stress
What are the variations of eczema distribution with age?
Infants: Cheeks and trunk
Older children/adults: flexures
Describe flare-ups
Red, vesicles, weepy, crusty
Excoriations, lichenification
What are the clinical requirements for diagnosis?
Itchy skin +1 of: o Onset < 2 years o Hx of dry skin o Atopy hx / hx in 1st degree relative o Past flexural involvement o Visible flexural dermatitis / or on cheeks, forehead or outer side of limbs in < 4 years
Describe eczema distribution in asian and black african?
On extensor surfaces rather than flexor
What is eczema herpaticum?
Widespread lesions that coalesce into large, denuded, bleeding areas that extend over entire body
Can have serious sequelae: Eye and meningeal involvement = scarring
RF: early-onset, severe atopic eczema, marked IgE elevantion, peripheral eisoniphilia, filaggrin gene mutations
Name a mild topical steroid + dose + brand name
Hydrocortisone 0.5-2.5%
Canestan
Name 2 moderate topical steroid + dose + brand name
Betamethasone 0.025%
(Betnovate)
Clobetasone butyrate
(Eumovate)
Name 2 potent topical steroid + dose + brand name
Fluticasone propionate 0.05%
(Cutivate)
Betamethasone valerate 0.1%
(Betnovate)
Name a very potent topical steroid + dose + brand name
Clobetasol propionate 0.05%
Dermovate
What is Psoriasis?
Hyperproliferation of keratinocytes and inflammatory cell infiltration
