Probably the most powerful single thing that makes people look younger these days is hair dye. Not all men can pull it off but, when its done well, it makes a huge difference. But as this treatment has become more common the incidence of allergies has increased.
Hair dye can either be:
Temporary – eg that purple hair dye that washes out after one shampoo.
Gradual eg Grecian that slowly darkens grey hair over weeks.
Semipermanent that lasts 6-10 washes. Henna was used by the Egyptians as a semipermanent hair dye 4000 years ago.
Permanent including peroxide bleaching and organic chemistry dyes. These almost always contain PPD (paraphenylenediamine).
PPD is almost always the cause of a hair dye allergy. Other dyes which begin with “para” can also cause an allergy as well as resorcinol and ammonium persulphate which are in some dyes. But PPD is the most common. The incidence of a reaction is said to be one in every 50,000 applications and this is the reason your package insert tells you to test the dye on a small patch of skin before use.
What can happen?
A mild itchy rash.
Blisters and weeping sores.
Swelling of the face and eyes.
Difficulty breathing (anaphylaxis).
What to do about it?
Call 111 immediately if there is any difficulty breathing or a feeling of swelling of the mouth or throat. This is an anaphylactic reaction, the same reaction as people who die from a beesting or peanut allergy.
Wash the dye off. Get rid of it. If possible make up a solution of 150g of salt and 50ml of hydrogen peroxide in a litre of water to pour on the hair and neutralise the PPD. If not use water.
Milder reactions can be treated with a steroid lotion for the rash and antihistamines for the itch. Wear a hat to prevent sunlight aggravating the reaction.
Avoid PPD from now on and try any alternative hair dye on a small patch first. If you had an anaphylactic reaction to the dye make sure you are close to a hospital or medical clinic before trying any new hair dye.
Allergic reactions to hair dye are not that rare. It pays to be aware.
Keywords: allergy hair dye