A physician will conduct a physical examination of the patient and examine the appearance of the skin. The physician will also compile a medical history and a list of symptoms. If an allergy is suspected, the physician will perform one or more allergy tests (e.g., allergy skin test).

Contact dermatitis is the most common symptom of henna stain allergy. There are several types of effective self-care treatment measures recommended for the treatment of contact dermatitis. These include:

• Applying calamine lotion and cool oatmeal baths to relieve itching
  
• Applying cold compresses to the blisters directly
  
• Applying hydrocortisone creams (nonprescription strength) to the skin
  
• Applying antihistamines directly to the skin to relieve itching
  
• Applying moisturizers to help restore the normal texture of the skin
  
• Washing with cool, soapy water immediately after exposure to neutralize and remove the offending substance

Prescription antihistamines may be used if over-the-counter antihistamines do not relieve the itching. Prescription corticosteroid medications may be topically prescribed to treat inflammation in a confined area.

Topical corticosteroid medications may lessen the inflammation but should be used carefully, as topical steroids can cause their own skin condition. If the rash covers a large portion of the skin or is severe, a physician may prescribe corticosteroid pills or injections. These are usually tapered gradually over a two-week period to prevent the recurrence of the rash. The healing period for a reaction to the additive p-phenylenediamine (PPD) may be extensive and take several weeks.