Snapshot A 25-year-old woman presents to her dermatologist reporting a new itchy skin rash. She reports going to a pool party recently, where she shared a hot tub with 10 other people. On her thighs and abdomen are clusters of small pustules and papules overlying an erythematous base. She is prescribed daily acetic acid baths and topical benzoyl peroxide. (Hot tub folliculitis) Introduction Clinical definition superficial inflammation of the hair follicles characterized by perifollicular papules and pustules Associated conditions acne neutropenia atopic dermatitis diabetes Etiology Bacterial Pseudomonas aeruginosa Staphylococcus aureus Fungal Malassezia spp. Candida spp. Tinea spp. more common in children Viral herpes virus Parasites Demodex spp. Epidemiology Demographics more common in men 20-40 years of age Risk factors prolonged use of antibiotics topical corticosteroids pin worms (especially folliculitis on the buttocks) exposure to hot tubs, pools, or baths containing contaminated water “hot tub folliculitis” caused by Pseudomonas aeruginosa immunodeficiency Presentation Symptoms clusters of pustules that wax and wane often pruritic Physical exam single or clusters of small pustules or papules surrounding a hair follicle on an erythematous base occurs on hair-bearing skin staphylococcal often occurs on face, buttocks, legs, and axilla pseudomonal often occurs on trunk candida often occurs in skin folds Studies Microbiology testing for bacteria, fungus, and virus indications if disease is refractory to standard therapy or are unusually severe Differential Pseudofolliculitis barbae Acne vulgaris Keratosis pillaris key distinguishing factors autosomal dominant rough papules on the skin with hard plugs Treatment Conservative daily acetic acid bath indication for gram-negative bacteria as this usually resolves without treatment Medical topical mupirocin indication first-line topical benzoyl peroxide indication first-line systemic antibiotics, anti-fungals, or anti-virals indication if therapy is refractory to first-line therapy Complications Deeper infection such as furuncle or carbuncle Alopecia if hair follicle is damaged Prognosis Waxing and waning nature Can progress into furuncle or carbuncle furuncle infection of hair follicules and associated with abscess carbuncle a collection of furuncles that drain through follicular orifices