Acne Flashcards
What are the 4 main processes causing acne?
Increase in sebum excretion rate (SER) Abnormal follicular keratinisation and desquamation (hypercornification) Colonisation with Propionibacterium acnes Inflammation
What is ‘Comedogenesis’?
accumulation of stuff in pilosebaceous duct
What is acne?
Any disease that begins with a microcomedo
What is acne vulgarisms?
a common disease of pilosebaceous unit characterised by comedones, papules and pustules
What is the process in which acne develops?
Increase in SER –> Seborrhoea –> ?androgens ?free fatty acids from sebum –> hyperkeratosis of follicle –> abnormal desquamation –> retention keratosis –> microcomedo
How does P.aureus affect acne?
thrives in sebum colonises in follicle
How does P.aureus cause inflammation?
products of P.aureus interact with host cells, causing inflammation
What are open comedones?description
blackheadsa) dilated orifice b) layered keratinous squamaec) P.acnes
What are closed comedones?description
whiteheadsundiluted orifice disordered keratinous squamous P.acnes
What are the inflammatory lesions involved in acne?
maculespapulespustulesnodulescysts
What are the differentials when considering a diagnosis of acne?
acne rosaceaperi-oral dermatitis folliculitis DLEdrug eruption
When should you consider an underlying endocrine disorder?
Sudden onset severhirsutism menstrual disturbances
Which factors aggravate acne?
occlusive cosmetics/hair productsheat/humidity excessive/vigorous washing manipulation of lesions exogenous medications
List some acne subtypes
acne vulgariscystic acne or acne conglobataacne fulminant acne excoriate neonatal acneinfantile acne endocrine acne occupational acne pomade/cosmetic acne drug induced acne tropical acne
outline the main ways of treating acne
patient educationantibacterials antibioticsretinoidshormonal topical or systemic medication
What is first line in mild /moderate disease?
antibacterials or retinoidslimited use in sensitive skin
What are examples of -topical antibacterials used?
benzoyl peroxide azelaic acid
What are the pros of using benzoyl peroxide?
no resistance some anti-inflammatory activity increased efficacy with antibiotic
What are the cons of using benzoyl peroxide?
irritation bleaching
What are the pros/cons of azelaic acid?
no resistance less effective than benzoyl peroxide irritation limits usefulness
What are the pros/cons of erythromycin/clindamycin?
well tolerated problems with resistance when used as mono therapy
When should systemic antibacterials be used to treat acne?
moderate to severe acneif failure of topical treatment if scarring consider if chest or back is also involvedcombine with topical agents
What are the topical retinoids that can be used?
IsoretinoinTretinoinAdapalone
What are the main problems associated with topical retinoids?
erythema and irritation photosensitivity teratogenicity
What are the main problems associated with topical antibiotics?
resistance limit use to 6 months
What are the first line of systemic antibiotics used?
cyclines - doxycycline - lymecycline - tetracycline
What are the second/third lines of systemic antibiotics used?
second line = macrolides third line = trimethoprim
How can you limit resistance problems when treating acne?
Sue BPOuse others only if necessary combination therapy avoid mixing antibiotic types simultaneously limit duration of treatment maintenance therapy with BPO/retinoid Retreat with same antibiotic
What is the mechanism of action of retinoids?
expulsion of mature comedones inhibition of comedone formation anti-inflammatory enhancement of penetration of other agents
What are the limitation of retinoids?
teratogenicity erythema and irritation of topical agents photosensitivity
How effective is oral isotretinoin?
Fabulously effective - reduced comedogenesis- reduces sebum production - decreases p.acnes and therefore inflammation
When is is isotretinoim indicated for use?
- severe acne- active acne with scarring - resistant disease- where rapid relapses on cessation of oral therapy - acne leading to psychological.psychiatric disease
How is isotretinoin given as treatment?
treatment usually for 4-6 months total cumulative dose is relevant 22-30% relapse rate
When is isotretinoin contraindicated?
contra-indicated in pregnancy/breast feeding effective contraception required (2 methods) through 3 months monthly pregnancy tests
What are the side effects of isotretionoin?
Mucocutaneous - dry skin, dermatitis, itching, dry mucosa, epitaxis, skin fragility, hair lossToxicity - increased lipids, deranged liver function, arthralgia/myalgia, disruption of night vision, initial fear of acne
What is an example of a hormonal treatment that can be used?
Dianette - variabel tolerance - obvious contraindications - increased risk of venous thromboembolism
How are scars treated?
excision laser resurfacing intralesional steroid for keloids dermabrasion microdermabrasion
What are the non-inflammatory lesions in acne?
open and closed comedones
