Cause:Hormonal changes of puberty; bacterial (corynebacterium acne)?,, iodides and bromides
Pathophys:Hypertrophic sebaceous glands lead to increased sebum production and desquamation, especially with androgen stimulation, w comedone formation; sebum undergoes lypolysis by bacteria, which, in turn, causes inflammation. Cystic acne is associated with increased androgen levels from partial adrenal 2I-OH deficiency or polycystic ovaries, hence low-dose dexamethasone and/or birth control pills help (Nejm 1983;308:981)
Teenagers; XYY genotype may correlate w severe acne vulgaris and early age of onset (Ann IM 1970;73:270); associated with seborrheic dermatitis
Sx:Acne; iodide and bromide types lack comedones and may be in unusual places
Si:Papules on erythematous base, pustules, comedones, nodules, cysts, scars
HIDRADENITISin axilla or groin, rx with topical and systemic antibiotics, and antibacterial soaps, intralesional steroids; birth control pills occasionally helpful. Avoid I + Ds; rx severe cases with excision of apocrine gland-bearing skin
r/o ACNE ROSACEA(Nejm 2005;352:793), which is central facial; has telangiectases, papules, and pustules without comedones or scarring; rx with dietary vasodilator restriction, topical rx with metronidazole 0.75% cream bid (Med Let 1989;31:75), azelaic acid 15% gel bid, and po tetracycline (Med Let 2007;49:5) w strict photo protection, as below
Rx:
(Nejm 2005;352:1463; Jama 2004;292:726)
Mild:
- Avoid facial creams; wash face bid and hair qod
- Topical rx (Med Let 1996;38:53) with:
- Benzoyl peroxide, resorcinol, salicylic acid (Pernox, Xerac, Fostex, Banoxyl, Syntex, Abiotin)
- Retinoids; all $35/15 gm
- Antibiotics:
- Erythromycin 2% soln gel or cream bid, or 2, 3, or 5% soln w benzoyl peroxide gel (Benzamycin)
- Clindamycin 1% gel, solution or lotion (Nejm 1980;302:503); w benzoyl peroxide (BenzaClin, Duac)
- Metronidazole 0.75% gel (Metrogel) $38/30 gm, or 1% cream (Noritate) qd-bid; $50/30 gm
- Azelaic acid (Azelex) 20% cream bid; or as 15% gel (Finacea) (Med Let 2003;45:76) bid esp for rosacea; adv effects: stinging, burning; $43/30 gm
Moderate:
- Oral antibiotics:
- Tetracycline (Med Let 2007;49:5) 250-500 mg po bid ($6/mo) until better, then qd and taper, or doxycycline 100 mg po bid ($25/mo) or minocycline 100 mg po bid ($50/mo), of its long-acting once a day form (Solodyn) ($500/mo); because of sunburn, use sunscreen or stop in summer, especially w doxycycline (Nejm 1976;294:43); beware of pregnancy in women since stains infants teeth
- Clindamycin po as good or better but higher C. diff colitis risk
- Erythromycin also works
- Azithromycin 250 mg po biw-tiw or less, expensive
- Antiandrogens
- Narrow band blue light (clear light is ineffective) (Med Let 2003;45:50)
- Handheld heat devices (Med Let 2007;49:51)
Severe/cystic:
- Retinoids:
- Isotretinoin (Accutane) (Med Let 2002;44:82) 1-4 mg/kg po qd × 5 mo after derm consult; $100+/mo; 95% remissions; adverse effects (FDA Bull 13:21): 33% teratogen in 1st trimester (Nejm 1985;313:837), difficult to obtain for potentially pregnant women (Nejm 1989;320:1007); elevated uric acid; regional ileitis; corneal opacities; elevated lipids may cause atherosclerosis (Nejm 1985;313:981); pseudotumor cerebri; hyperostosis, at least at higher doses, which are used in ichthyosis (Nejm 1983;308:1012); arthritis and fatigue limit use in athletes (R. Kenney 12/85); possibly depression and suicide
- Acitretin (Soriatane) (Rx Let 1997;4:64) po qd; less long-acting metabolites than isotretinoin but alcohol counteracts this advantage by converting it to those toxic forms
- Low-dose dexamethasone, with or without birth control pills (Nejm 1983;308:981)
- Intralesional steroids
- Cryotherapy