Hair dyes are used to change the natural hair color temporarily. People have various reasons in using hair dyes: covering the gray or simply getting the perfect hair color. Through the years, the number of people using hair dyes has increased. Likewise, the number of people reported hair dye allergy has also increased significantly. What causes allergic reaction to hair dye?
Allergy to hair dye is caused by 4-paraphenylenediamine (PPD), a chemical used in 2/3 of all permanent hair dyes. The chemical has been in the market since 1909. PPD has many other names: Ursol, Rodol, Orsin, para-Aminoaniline, para-Diaminobenzene, 1,4-benzenediamine, 1,4-phenylenediamine, and p-phenylenediamine. Because PPD is dangerous to human health, some countries banned or limited the use of PPD in hair dyes. In the U.S., PPD is allowed only in hair dyes and not permitted in other cosmetic products designed for direct skin application.
Symptoms of Hair Dye Allergy
According to Healthhype.com, there are three types of symptoms caused by hair dyes: allergic contact dermatitis, contact urticaria, and anaphylactic shock.
Allergic contact dermatitis (ACD) is a form of skin inflammation with symptoms such as redness, swelling, itching or blistering. ACD occurs in people who are genetically predisposed to develop sensitivity with PPD. Symptoms of ACD do not show immediately at the initial contact to PPD because at least 10 days is required for a person to develop sensitivity. Within these days, the immune system is preparing for subsequent exposures by producing antibodies against PPD. On the second and subsequent use of PPD dye, ACD symptoms show up after 6-72 hours from the time of exposure. Immune cells such as lymphocytes and macrophages attack PPD molecules and then ACD symptoms begin to appear at the ears, eyelids, scalp, face, neck, and other body areas.
Another symptom of hair dye allergy is contact urticaria which is marked by itching and small pale or red swellings in the skin that can last for few days. Unlike contact dermatitis, contact urticaria occurs in minutes to about an hour after exposure to PPD. As a reaction to PPD, the immune system produces immunoglobulin E (IgE) antibodies and histamine. Histamine causes the dilation of skin blood vessels; this results to the leakage of blood plasma into the skin resulting to redness and swelling. Besides from skin symptoms, sneezing, wheezing, swallowing difficulty, and vomiting can appear.
Anaphylactic shock is the most dangerous symptom of hair dye allergy because it is fatal. Though very rare, anaphylactic shock due to PPD allergy has claimed few lives. The signs of anaphylactic shock include itching, swelling (edema), breathing difficulty, confusion, serious drop in blood pressure, weak pulse, loss of consciousness, and death. A person who has anaphylactic shock needs immediate medical help to prevent death.
Take note that hair dye allergy symptoms are similar to the symptoms of peanut, strawberry, latex, mold, and sulfite allergies.
Hair Dye Allergy Treatments
If allergic reactions occur after applying hair dye, the hair should be rinsed immediately with water and washed with mild shampoo and 2% hydrogen peroxide. The hydrogen peroxide will break the adherence of PPD to hair strands.
Antihistamine is the medication used for mild allergic reactions like skin rashes and itching. For the fatal anaphylactic shock, epinephrine shot is given to the patient. Epinephrine relaxes the airways and constricts the blood vessels. Since epinephrine is injected directly to the bloodstream, it will work right away.
If the symptoms are getting serious, seek medical help immediately.
Prevention of Hair Dye Allergy
It is highly advised to perform patch test before using any hair dye. Patch test is easy to do, just make a hair dye solution and then use a cotton swab to apply a drop of the solution behind the ear or on the inner side of the elbow for 48-72 hours. The test is negative if no rashes or irritations occur; therefore it is safe to use the hair dye.
Henna dye is a good alternative to synthetic dyes with PPD. The dye is derived from the dried crushed leaves of henna, Lawsonia internis. Henna dye contains tannins, red pigments also found in grapes. Take note that there are henna dyes in the market that contain PPD. Thus, perform a patch test before using henna dye.
Other Important Things to Know
Besides PPD, other chemicals in hair dye can also cause allergy such as 6-hydroxyindole, p-methylaminophenol, and Isatin.
People with PPD allergy can also develop sensitivity to chemicals related to PPD such as azo groups (found in ballpoint pen inks, hair dyes, and food & medication coloring), sulfa drugs, local anesthetics e.g. benzocaine & procaine), p-aminosalicylic acid, and p-aminobenzoic acid (PABA, found in sun-protective creams).[ad#afterpost]