Pilosebaceous Diseases

Abstract

Clinical: Common pilosebaceous inflammatory condition that typically presents in adolescents as comedones, papules and pustules on the face, chest, shoulders, and back. Comedones may be open (blackheads; papules with open pores filled with black-appearing keratin) or closed (whiteheads; yellow-white closed papules). Cysts, nodules or scarring seen in more severe cases. May continue into adulthood and may worsen with menses in females. Unclear pathogenesis believed to start with follicular plugging by keratin in the setting of abnormal keratinocyte proliferation in the infundibulum. Inflammatory environment created in part by overgrowth of bacteria (especially Propionibacterium acnes) and androgenic stimulation of sebaceous glands (e.g. adrenarche in males and hyperandrogenic states such as congenital adrenal hyperplasia or polycystic ovarian syndrome). Acne neonatorum (neonatal cephalic pustulosis), self-resolving condition presents in newborns and resolves by 3 months, is traditionally thought to be due to circulating maternal hormones with conflicting findings implicating Malassezia fungal colonization. Acne conglobata (nodulocystic acne) seen in follicular occlusion triad with dissecting cellulitis of the scalp. Folliculitis decalvans and hidradenitis suppurativa. Pilonidal sinus or cyst (sacral sinus or cyst with perifollicular fibrosis and granulomatous inflammation in males) sometimes included and referred as follicular tetrad or acne inversa.