Coloring your hair is a fun and easy way to change or freshen your looks or to cover the gray hairs. As fun and harmless as it sounds, sometimes it can be everything but that. Of course, we are talking about hair dye allergies. The question that arises after something like this happens is, why does allergic reaction to hair dye happen and how long does it last?
Permanent and semi-permanent commercially produced hair dyes have a chemical called paraphenylenediamine, or PPD for short in them. When mixed with peroxide, an oxidization happens, in which case PPD can cause a mild or severe allergic reaction. These allergic reactions are characterized by redness, inflammation, itchiness, and, in more severe cases, the swelling of the skin around the hair line, neck, beard, and even eyelids.
How Long Until It’s Gone?
So, how long does it take until the nasty symptoms of an allergic reaction are gone? As with all the allergies, the healing time may vary. If a hair dye caused contact dermatitis, the symptoms will last for about ten days from the usage of the hair dye. The symptoms will appear in five to 72 hours from the application, and they can manifest in the form of redness, itchiness, and inflammation of the scalp.
Additionally, hair dye can cause urticaria which can manifest in the form of sneezing, vomiting, red patches, swelling of the eyelids, and difficulty with swallowing. Urticaria can last for about 6 weeks. Don’t forget that the chemicals in hair dye can also cause anaphylactic shock. This happens rarely, however the symptoms may include shortness of breath, facial swelling, and blood pressure drop. This is a deadly condition and if you or someone else has the symptoms, call 911 immediately!
How Long Until It Manifests?
Generally speaking, allergic reactions to the chemicals in hair dye can appear anywhere from a few minutes to ten days from the first application, i.e. contact with the chemical. Usually though, any symptoms should manifest themselves up to 72 hours after the application, therefore, it is essential to perform a simple patch test before you use any hair coloring product.
To do a patch test, apply a small amount of the hair dye with the developer behind your ear or to the skin of your inner elbow. Let the dye sit for 48 to 72 hours and check for any symptoms. If there are none, you should be safe and you can use the hair dye freely.
Before all remedies comes the first and the most successful treatment option and that is prevention. Since there is no way to know if you are allergic to PPD, always perform a patch test before using a hair dye. To prevent allergic reactions even further, go for the hair dyes that do not contain PPD.
Note that PPD comes in many name forms, so make sure to bring your magnifying glass to the drugstore and look for the following ingredients: phenylenediamine, benzenediamine, aminoaniline dihydrochloride, and also PPDA, 4-Phenylenediamine, para-Diaminobenzene (or p-Diaminobenzene), para-Aminoaniline (also known as p-Aminoaniline), 4-Benzenediamine, 1,4-Phenylenediamine, or Ursol, Orsin, and Rodol. Also, avoid ingredients such as para-aminosalicylic acid and Benzocaine and procaine, which are also used as local anesthetics.
If possible, avoid the hair dyes that come in two separate containers or bottles, as they are considered to be the oxidation hair dyes that can cause the allergies. Additionally, since PPD and chemicals similar to it are mostly concentrated in darker hair dyes such as brown and black, consider going blonde or getting highlights instead of coloring your whole hair and applying the dye to your scalp.
Nowadays you can find natural hair dyes that do not contain these chemicals, or, alternatively, use a semi-permanent dye, but make sure to carefully review the ingredients list as well.
Most importantly, if you are allergic to PPD, make sure to inform your doctor and dentist, since they could be using an anesthetic that contains one of these chemicals and you can have an allergic reaction all over again. Being well informed and prepared is key when it comes to fighting off the allergies, so do not be afraid to speak up and to ask about the ingredients of any anesthetics or other chemicals your doctor or dentist plans to use to treat you.