Dermatitis accounts for about 30 percent of all illnesses in the workp
lace. A thorough exposure history is the most important element in acc
urate diagnosis of skin lesions. in certain cases, skin lesions may be
valuable diagnostic clues to the presence of systemic toxicity. Irrit
ant and allergic contact dermatitis, photosensitivity contact dermatit
is, and contact urticaria are examples of skin lesions that may be cau
sed by exposure to an environmental agent.