benzofurans and Dermatitis--Occupational

Chloracne is an acneiform skin eruption that is still the most sensitive indicator of systemic poisoning caused by chemicals belonging to the group of chlorinated polycyclic aromatic hydrocarbons. Generally these chemicals are known as dioxins, dibenzofuranes, and PCBs. The cause of chloracne is probably interference of these chemicals with vitamin A metabolism in the skin, resulting in disturbances of the epithelial tissues of the pilosebaceous duct. A study of workers in a factory where chloracne is endemic is described. The product manufactured, pentachlorophenol, a wood preservative, was found to be contaminated with dioxins (congeners of TCDD) and dibenzofuranes. Blood levels of these chemicals in affected workers are given, along with supporting evidence of disturbances in vitamin A (retinoid) metabolism as demonstrated in skin biopsies.

Topics: Acne Vulgaris; Benzofurans; Dermatitis, Occupational; Dioxins; Humans; Hydrocarbons, Chlorinated; Occupational Exposure; Polychlorinated Biphenyls

Topics: Abnormalities, Drug-Induced; Animal Diseases; Animals; Benzofurans; Biphenyl Compounds; Cattle; Cattle Diseases; Chemical and Drug Induced Liver Injury; Chickens; Dermatitis, Occupational; Dioxins; Edema; Environmental Exposure; Herbicides; Humans; Hydrocarbons, Halogenated; Poultry Diseases

Topics: Adult; Allergens; Benzofurans; Dermatitis, Allergic Contact; Dermatitis, Occupational; Eczema; Humans; Irritants; Male; Plants; Sesquiterpenes

Chloracne is caused by exposure to certain halogenated polycyclic hydrocarbons such as polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs). In chronic exposure it is not known what level of intoxication, represented by the level in blood lipids, is sufficient to cause chloracne. Blood levels of the congeners of PCDD/Fs were determined in four groups of humans. One group had clinically visible chloracne due to exposure in a hexachlorobenzene workshop of a large chemical factory. A second group was exposed in the same workshop, but had no skin changes. There were two control groups: one non-exposed group of maintenance workers from the same chemical factory, and one group of healthy individuals living elsewhere. Blood levels were converted to toxicity equivalents of tetrachlorodibenzo-p-dioxin (TCDD). In the chloracne group blood levels in toxicity equivalents (TEQs) ranged from 1168 to 22,308 pg/g blood lipid. In the exposed without chloracne this ranged from 424 to 662 pg/g. It is concluded that the level to develop chloracne is between 650 and 1200 pg/g TEQ. The contribution of TCDD was rather small, and the main causative congeners were the hexachlorinated dibenzodioxins and dibenzofurans (HxCDD/Fs); lipid-based blood levels in absolute amounts that may cause chloracne are in the range of 2-3.5 ng/g HxCDD, and 2-5 ng/g HxCDF.

Topics: Acne Vulgaris; Benzofurans; Case-Control Studies; Dermatitis, Occupational; Dioxins; Humans; Lipids

Topics: Acetophenones; Adult; Benzofurans; Chemical Industry; Dermatitis, Allergic Contact; Dermatitis, Occupational; Eczema; Facial Dermatoses; Forearm; Hand Dermatoses; Humans; Male

A 30-year-old pharmacist suffered from acute allergic contact dermatitis due to 4-chloro-7-nitrobenzofurazan (NBD-Cl). Contact allergy towards this reagent and 2 of its reaction products was proven by patch tests. As NBD-Cl has not been reported as an allergen before, the characteristics of this chemical and its use as an analytical reagent are briefly surveyed. Similarities to dinitrochlorobenzene (DNCB) are pointed out.

Topics: Acute Disease; Adult; Benzofurans; Dermatitis, Contact; Dermatitis, Occupational; Female; Humans; Praziquantel

Topics: Acne Vulgaris; Azo Compounds; Benzofurans; Dermatitis, Occupational; Humans; Naphthalenes; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins

Two forest workers affected with allergic contact dermatitis, which occurred only during work in forest areas, showed positive patch test reactions to lichens containing usnic acid and to isolated usnic acid. Lichens are plants composed of fungi living in symbiosis with algae. Usnic acid, one of the lichenic acids which accumulates in lichenized fungi, is a monobasic acid with dibenzofuran structure and antibiotic properties. Dibenzofuran is chemically related to furocoumarans. Lichens are plentiful in temperate zone forests and allergy to usnic acid represents some part of the "cedar-poisoning" problem in British Columbia. Geographical distribution of lichens containing usnic acid suggests that allergy to usnic acid will be found to be more common than presently recognized.

Topics: Adult; Benzofurans; Dermatitis, Contact; Dermatitis, Occupational; Forestry; Humans; Lichens; Male