Snapshot A 12-year-old boy with no significant past medical history presents with acne to his pediatrician’s office. He has recently started practice for the wrestling team. He admits to not maintaining great hygiene, eating lots of junk food, and being stressed about an upcoming meet. On physical exam, he has dozens of erythematous papules, pustules, and cysts. On closer exam, he also has atrophic scars on the lateral forehead, consistent with permanent scarring from previous acne lesions. He is started on topical retinoids and topical benzoyl peroxide. His pediatrician suggests that he also consider a systemic retinoid if this topical therapy does not work. SummAry Clinical definition common chronic skin condition characterized by inflammatory and non-inflammatory lesions Pathogenesis blockage or outlet obstruction of pilosebaceous unit forms comedones from ↑ sebum production abnormal desquamation of keratinocytes and its accumulation colonization of bacteria Propionibacterium acnes inflammatory lesions result from leakage of sebum from comedones into dermis secretion of proinflammatory cells by Propionibacterium acnes ↑ androgen production also plays a role in acne formation Associated conditions polycystic ovary syndrome Cushing syndrome congenital adrenal hyperplasia Epidemiology Incidence very common Demographics up to 85% of teenagers but can affect adults as well more severe around puberty Location face, back, neck, chest, and upper arms Risk factors menstrual cycle emotional stress occlusion of skin with greasy products excessive sweating pregnancy milk consumption Etiology Multifactorial androgen production medications steroids Presentation Symptoms nodular or cystic acne may be painful Physical exam inflammatory lesions erythematous papules, pustules, cysts, or nodules non-inflammatory lesions are comedones, which are dilated hair follicles filled with keratin, sebum, and bacteria open comedones are known as blackheads closed comedones are known as whiteheads scarring pitting and puckered indentation in skin Studies Making the diagnosis most cases are clinically diagnosed Differential Hidradenitis suppurativa Rosacea Folliculitis Treatment Management approach multiple factors go into the decision to treat acne, including severity of acne, type of acne, presence or potential for permanent scarring, concern for side effects, and adherence to therapy Medical benzoyl peroxide topical or wash indication for mild comedonal/inflammatory acne first-line antibiotics topical indications for mild non-comedonal acne can be tried before escalating to retinoids used in conjunction with benzoyl peroxide or topical retinoid drugs clindamycin erythromycin systemic indications for mild to moderate non-comedonal or comedonal acne should not be used long-term or as monotherapy can be tried before escalating to retinoids can be tried if acne is refractory to other topical treatments drugs tetracycline minocycline doxycycline causes photosensitivity retinoids topical indications for mild to moderate acne, especially with comedones and inflammatory acne often first-line when combined with an antimicrobial agent (topical or systemic) drugs adapalene tazarotene tretinoin systemic indications for moderate to severe acne, especially cystic acne for patients with existing or potential for permanent scarring contraindication pregnancy teratogenic to fetuses and can cause cleft palate and cardiac abnormalities drugs isotretinoin requires 2 pregnancy tests and use of 2 different forms of contraception for at least 1 month prior to starting hormonal therapy indications for severe acne or acne refractory to other therapy for acne that seems to correspond with menstrual cycle drugs oral contraceptives spironolactone Complications Permanent acne scarring and cosmetic disfigurement Prognosis In many cases, acne will resolve in adulthood however, hormonal acne may persist