Snapshot A 25-year-old woman with bipolar disorder managed by lithium presents to her dermatologist for a new onset painful rash in her inguinal area. She reports multiple lesions that seem like acne but are much larger than any acne she’s ever had. On physical exam, she has multiple deep-seated, tender, and erythematous nodules and abscesses that were openly draining purulent fluid. She is immediately given a warm compress and oral antibiotics. She is counseled about this life-long disease and is advised to stop taking lithium and find an alternative medication. Introduction Clinical definition chronic disease of occluded aprocrine glands and hair follicles characterized by painful cutaneous draining lesions, abscesses, and pilonidal sinuses this disorder does not respond well to antibiotics Epidemiology incidence 1-4% worldwide demographics 3:1 female to male ratio onset in 11-50 years of age rarely persists after menopause risk factors positive family history smoking obesity mechanical friction (wearing tight clothes) medications lithium medroxyprogesterone acetate sirolimus Etiology plugged apocrine gland or hair follicle Pathogenesis exact mechanism is unknown but theories include hormonal overstimulation of ductal keratinocyte production this leads to accumulation of keratinocytes, leading to occlusion (comedos) ongoing occlusion and accumulation of material leads to increased innate immunity reaction, exacerbating accumulation of cellular debris and cyst formation drug-induced disease lithium may increase neutrophil migration and epithelial cell proliferation to subsequently occlude follicles medroxyprogesterone acetate acts as an androgen, inducing hormonal stimulation of epithelial material production Prognosis chronic disease with recurrence prognostic variable negative obesity smoking Presentation Symptoms painful lesions that drain recurrent lesions Physical exam tender nodules, pustules, or abscesses with purulent or serous drainage may coalesce into multiple draining sinuses forming a honeycombed pattern may have scars from prior lesions location most commonly occurs in axillary, inguinal, and anogenital regions Studies Labs bacterial culture to look for superinfection Diagnostic criteria 1 or more painful deep-seated nodules, abscesses, or draining sinuses poor response to antibiotics chronic and recurrent disease Differential Folliculitis Vasculitis Acne vulgaris Treatment Conservative weight loss and smoking cessation indication may help with reduction of recurrence warm compresses indication to minimize symptoms Medical topical antibiotics indication for mild disease drugs topical clindamycin 1% oral antibiotics indications for mild disease not responsive to topical therapy for maintenance therapy between outbreaks drugs minocycline doxycycline amoxicillin-clavulanate clindamycin immunosuppressants indications for moderate or severe disease not responsive to antibiotics drugs adalimumab infliximab ustekinumab cyclosporine Complications Scarring and fibrosis incidence treatment Poor quality of life and psychologic burden Secondary superinfection