An allergy from using hair dye can be treated by washing the skin with cool water and mild soap as soon as a rash appears, according to WebMD. Patients may also apply hydrocortisone cream on the affected area or take an oral antihistamine to relieve itching.
Allergic reactions from hair dye that produce blisters on the skin can be treated by applying a cold moist compress on the affected area for 30 minutes, three times each day, according to WebMD. Patients should resist the urge to touch the rash or affected area of the skin to reduce the risk of bacteria causing infection. If symptoms persist or the rash does not disappear, it may be necessary to have a physician evaluate the affected skin. In some cases, physicians prescribe antihistamine ointment or steroid pills to treat an allergic reaction to hair dye.
An allergy to hair dye often produces red and itchy skin rash known as contact dermatitis, according to WebMD. The skin may appear to be tender because the protective layer of the skin is damaged. The skin affected may also burn. Rashes typically occur when an individual's skin is exposed to an allergic agent which springs the immune system into action, releasing histamine chemicals to fight the allergy. As a result, a red, bumpy, itchy rash develops on the skin exposed to the allergy.