Success Stories

It can be a salon’s worst case scenario. You’ve coloured a client’s hair and they’ve come back to you showing a reaction on their scalp or face. In cases of a hair dye allergic reaction, if you’re alert and sufficiently knowledgeable, you can identify that the reaction is allergic. It’s not just a temporary irritation. One of the most important pieces of advice you can give your client is to go and see their GP. They need medical advice to treat the hair dye allergic reaction effectively.

Getting an appointment to see a GP may be easier said than done. But once there, the GP will want to know exactly what’s happened, when, and whether it’s happened before. After taking a close look at the situation, the GP may recommend the client sees a consultant dermatologist if it’s a hair dye allergic reaction. This allows the issue to be examined and explored more thoroughly.

John English is a consultant dermatologist in Nottingham. Like many of his colleagues, he’s seeing a considerable increase in the number of people with evidence of allergy to cosmetics products. “It’s not just hair dye that’s the culprit”, he says. “The biggest increase we’re seeing is sensitivity to a common preservative found in many leave-on and wash-off products called metathylisothiazolinone.”

A dermatologist will test their patient for allergy using a diagnostic patch test. This involves placing an adhesive strip or strips on the skin, usually on their upper back. The strip contains small, shallow containers or ‘chambers’. These can be filled with substances that test for allergy or sensitivity to different products or allergens, including for a hair dye allergic reaction.

We need to educate

An allergen is a substance that causes allergy or sensitivity in an individual. Some allergens are found in foods like nuts and seafish, others are found in man-made chemicals and products. Different people will react to allergens in different ways. Some people may react severely to an allergen that causes no response in others.

The dermatologist might choose to test for just one or two allergens or a number at the same time, depending on the patient’s history. But however many they’re testing for, they’ll keep a careful note of what’s been tested and on which patch of skin.

The strip is left on the skin for at least 24 hours, and the patient is told not to wash the area during that time. The dermatologist will then remove the strip and examine the skin. If there’s been a reaction, the skin is likely to be raised and red. Often the dermatologist will use a special reference chart to measure whether there’s been a reaction, especially in cases of a hair dye allergic reaction. They assess how severe it is.

PPD

“I recently saw a patient who’d had a severe reaction to colour, on both their hair and eyebrows,” says John English. “I tested for 55 substances at the same time and she tested positive for 3: bleach, ammonium sulphate and PPD, which is the most active substance in dark hair colour.”

Following that result, what was John English’s advice to the patient? Some of his colleagues advise a patient never to use hair colour again in this situation. However, he takes a more pragmatic view. “I think we have to acknowledge that colour’s not going away. My view is that unless the case is very severe, colour can still be used. The hairdresser must be very careful, and the colour should not touch the surface of the skin.”

It’s a Catch-22 situation. Because hair colour can be dangerous for some people, a skin test should always be used before applying colour. But the test itself contains small amounts of the very substance that can cause a problem. So what’s to be done?

“In an ideal world”, says John English, “we would ban all PPD-based hair colour, but that’s not going to happen. The message has to be: be very careful, don’t overuse colour and test every time to prevent a hair dye allergic reaction.”