chloracne

Chloracne is a form of acneform dermatitis caused by exposure to chlorinated aromatic hydrocarbons, particularly halogenated dioxins such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds including polychlorinated biphenyls (PCBs) and certain chlorinated pesticides. It is not caused by ordinary acne and may reflect systemic toxicity from environmental or occupational exposure.

Onset typically occurs weeks to years after exposure. The eruption features comedones (blackheads and whiteheads), inflammatory papules, and deeper nodules. Lesions often involve the face, behind the ears, neck, shoulders, and upper trunk and can be accompanied by itchiness and perifollicular inflammation. Hyperpigmentation and milia may occur as sequelae.

Diagnosis is clinical, based on a compatible exposure history and the characteristic eruption. Skin biopsy is rarely necessary but can show follicular plugging with hyperkeratosis and a mixed inflammatory infiltrate if performed.

Treatment focuses on eliminating exposure and managing skin lesions. Immediate cessation of contact with the offending compound is essential. Dermatologic management follows acne protocols: topical retinoids, benzoyl peroxide, and topical antibiotics; systemic antibiotics or systemic retinoids (such as isotretinoin) may be considered for extensive or persistent disease. The safety profile of systemic therapy requires careful monitoring.

Prognosis varies with the extent of exposure and the speed of exposure removal. Some lesions improve after exposure ends, but chloracne can persist for months to years and may result in scarring. Prevention centers on occupational safety, environmental controls, and early recognition of exposure-related skin changes.