Contact dermatitis is an acute or chronic inflammatory reaction that occurs at the site of skin mucosal contact due to exposure to certain exogenous substances. The etiology can be divided into primary irritants and contact sensitizers, and common leather products and hair dyes may cause contact dermatitis. Contact dermatitis can be divided into acute, subacute and chronic according to the course of the disease, in addition there are some etiology and clinical manifestations and other aspects with some special clinical types. 1, acute contact dermatitis: the onset of the disease is more acute. The lesions are mostly confined to the contact area, and a few can spread or involve peripheral areas. The shape of the lesions is related to the contact material, with clear boundaries. Patients often feel pruritic or burning pain, a few patients have systemic symptoms. 2, subacute and chronic contact dermatitis: If the irritation of the contact material is weak or low concentration, the lesions can be subacute at first, manifested as mild erythema, papules, unclear boundaries. Long-term repeated exposure can lead to chronic local lesions, manifested as mild hyperplasia and mossy lesions. 3, special types of contact dermatitis: acute, subacute or chronic dermatitis caused by contact with cosmetics or hair dyes, the condition varies in severity. Special types also include diaper dermatitis, lacquer dermatitis, airborne contact dermatitis. Treatment of this disease involves finding the cause, removing the exposure and treating it symptomatically, and trying to avoid re-exposure to the allergen to avoid recurrence.