The specific time for contact dermatitis to improve depends on the nature of the contact allergen, the individual’s allergic constitution, the severity of the condition, and many other factors. If the contact dermatitis is mild, it will improve in 1-2 weeks after the allergens are removed and treated symptomatically. However, chronic contact dermatitis caused by severe symptoms or repeated exposure to allergens can have a longer duration. Contact dermatitis is an acute or chronic inflammatory reaction that occurs when the skin or mucous membranes come into contact with certain exogenous substances, mainly manifesting as erythema, swelling, blistering, blistering, or even necrosis at the contact site. The actual dermatology department should be consulted as soon as possible to choose safe and effective drugs for treatment under the guidance of a professional doctor to avoid aggravation and prolonged healing time. Contact dermatitis is often accompanied by varying degrees of itching, do not scratch and hot water scalding to prevent aggravation of the lesions.