Occupational dermatology is the facet of dermatology that deals with skin diseases the cause or aggravation of which is related to some exposure in the workplace. By its nature, occupational dermatology is also related to occupational and preventive medicine. The ideal role of a medical practitioner involved in occupational dermatology is to diagnose and treat patients and to determine the cause of the occupational skin disease and make recommendations for its prevention. Making the diagnosis .and offering treatment, determining cause, and recommending preventive measures can all be difficult undertakings. Many references on occupational skin disorders are available. Occupational dermatology covers a. wide variety of skin diseases. The causes of occupational skin disorders can be grouped into the following general categories: 1. physical insult (friction; pressure, trauma, vibration, heat, cold, variations in humidity, ultraviolet/visible/infrared radiation, ionizing radiation, and electric current) 2. biologic causes (plants, arthropods, bacteria, rickettsiae, viruses, fungi, and parasites) 3. chemical insults (water, inorganic acids, alkalis, salts of heavy metals, aliphatic acids, aldehydes, alcohols, esters, hydrocarbons, solvents, metallo-organic compounds, lipids, aromatic and polycyclic compounds, resin monomers, and proteins) Because epidemiologic data show that contact dermatitis accounts for 90% to 95% of all occupational skin diseases this entity is emphasized here. Other occupational skin diseases that are discussed include contact urticaria, skin infections, and skin cancers.