An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Volume 4.

Abstract : Chloracne, a chronic acneiform eruption with a highly specific cutaneous distribution, was first described by Von Bettman in 1897 as an occupational disease in German industrial workers. It was not until 1957 that it became recognized as a very specific consequence of exposure to chlorophenols (1,2). A recent review article summarizes the unique clinical manifestations of this skin condition (3). Early animal researchers employed the rabbit's ear as a model for assaying the effects of chloracnegenic compounds (4,5). Other experiments on hairless mice produced histopathologic changes similar to those that occur in humans exposed to tetrachlorodibenzo- p-dioxin (TCDD, or dioxin) including hyperkeratotic changes in the sebaceous follicle with plugging of the orifice, hyperkeratinization of the stratum corneum, and keratin cyst formation (6,7). The earliest descriptions of chloracne-like disease date back to the turn of the century (8). It is a relatively rare dermatitis with fewer than 4,000 cases documented world-wide (9); most cases have occurred in chemical plant workers or in victims of industrial accidents (10-13). Chronic conditions associated with severe chloracne include actinic elastosis, acne scars, and hypertrichosis (14,15). Epidermoid inclusion cysts seen in biopsy specimens are considered pathognomonic (16). The occurrence and severity of chloracne appear to be dose-related but may depend on other factors including the route of adnnnistration, age, genetic predisposition, and the presence of acne vulgaris and other dermatoses (14,17,18). More recent studies in rats have documented that the extent of dermal absorption is inversely related to age (19). This observation may be relevant to the finding in the industrial explosion at Seveso, Italy, that most cases (170 of 193 exposed) of chloracne occurred in children (10,11,13).