[Skin diseases associated with environmental factors].

BACKGROUND: Multiple environmental exposures may derange the regulatory and repair mechanisms of the skin and lead to dermatological disease.

OBJECTIVES: Provide an overview of non-allergic skin diseases associated with environmental factors.

MATERIALS AND METHODS: Review of current scientific evidence for associations of non-allergic skin diseases with environmental exposures: irritation, chemicals, infection, UV-radiation, temperature.

RESULTS: Predisposition (constitution e. g. for atopic dermatitis, psoriasis and filaggrin gene mutations) and exposure (environment) are crucial for disease development or maintenance of health in an individual. Specific chemical and contagious agents lead to characteristic skin diseases (e. g. halogen acne) which under certain conditions may be recognized as occupational disease. The most frequent cause for irritant contact dermatitis is water (wet work). Natural optical radiation of different wavelength may cause light-induced inflammatory skin diseases. Phototoxic reactions due to psoralens, furocoumarins and drugs are frequent. The polymorphous light eruption is not an exogenous delayed type allergy, but seems to be a reaction against a UV-induced neoantigen of the skin. UVB exhibits direct mutagenic effects on DNA. Sun exposure and defective DNA-repair mechanisms are risk factors for skin tumors. Heat/cold exposure under specific conditions also triggers skin diseases (primary: congelations, frostbite, heat burn, scalding, chronic-inducible urticaria; secondary: deterioration of preexisting inflammatory diseases (e. g. systemic sclerosis)).

CONCLUSIONS: To keep the skin healthy, an early identification and elimination of harmful environmental factors and treatment of early disease stages is necessary. This requires strategies of environmental prevention and behavioral prevention, as well as global action (e. g. with regard to increasing incidence of skin cancer).