Henna is most commonly used for hair dyes and temporary tattoos. Some people experience allergic reactions when henna comes in contact with their skin. For these people, prolonged or repeated exposure can pose serious risks. Knowing what to look for and how to treat henna allergies can diminish life-threatening reactions.
Symptoms of a henna allergy are similar to those of other allergies. They can include sneezing, swelling and hives, and difficulty breathing due to a restricted airway.
Henna itself seldom causes an allergic reaction. However, additives are used in making the henna paste to boost colour or speed up the colouring process. P-pheynlenediamine (PPD) makes the naturally reddish brown henna more black. Although it's safe for hair colouring, it can irritate the skin, leading to an allergic reaction.
If a henna allergy is suspected, you may try the following applications: calamine lotion, cold compress, hydrocortisone creams or antihistamines. An oatmeal bath will also alleviate itching.
People who experience a reaction to the PPD additive in henna tattoos are susceptible to having more serious reactions with increased exposure. Therefore, if you have encountered an allergic reaction, you are advised to avoid further henna tattoos or having henna come in contact with the skin.
The Food and Drug Administration (FDA) doesn’t endorse henna for direct skin contact. Therefore, caution should be used when receiving a henna tattoo.