An allergic reaction to hair dye is treated as contact dermatitis and involves taking oral antihistamines to reduce rashes or reaction symptoms as well as corticosteroid medication that reduces inflammation, according to WebMD. Antihistamines are taken in pill form, whereas corticosteroid medications can be applied to the reaction area as a skin cream or ointment, orally in pill form or as an injection.
Self-care for allergic reactions to hair dye includes washing the reaction area with cool water and soap to remove the substance, explains WebMD. Patients who have blisters develop as part of the allergic reaction can apply cold compresses to the head or affected area for 20 minutes at least three times a day. Individuals with extreme itching can soak the affected area in a cool oatmeal bath or apply calamine lotion, especially if a rash develops on the skin, to reduce itching and discomfort.
It may be necessary to consult with an allergy specialist if symptoms do not subside within a few days, warns WebMD. Patients should avoid scratching the affected area, as abrasive brushing to the scalp can worsen inflammation. Oral medications prescribed by a physician should be continued until the prescription is finished to avoid rashes from reappearing. Medications are often administered for three to five days or may continue up to a month.