Hair dye reactions

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The reactions that occur to any kind of hair dye are not uncommon. They range from irritation that occur locally in areas in direct contact with the hair dye to an actual allergy which provokes local symptoms but can also trigger a systemic reaction that affects other parts of the body.

In both cases, the symptoms can vary from mild to severe. A local irritation tends to affect the scalp, neck, ears, forehead and eyelids. The generalized symptoms may include widespread itching, urticaria and anaphylaxis in rare cases.

Chemicals used in hair dye

Hair dye products contain a variety of chemicals and almost any of these can trigger sensitivity reactions among highly sensitive individuals. Nevertheless, there are a group of recognized triggers that you should be familiar with.

Paraphenylenediamine (PPD)

Hair dye reaction
A patch test is done by applying a small amount of dye solution either behind the ear or on the inner elbow and allow to dry and leave uncovered for 48 hours. If rashes or irritation develops in the area tested, the individual should not use the hair dye.

This is present in permanent hair dyes particularly those with darker shades. These usually require two components – PPD-based dye in one bottle along with various chemicals in a second bottle.

PPD is actually colorless but becomes colored once oxidized by oxygen released from the second bottle. During the oxidation process, the chemical acts as a sensitizer. Once the process is complete, the dye is generally safe and will not continue to cause issues once the initial symptoms have settled down.

Measures to prevent hair dye reactions

  • The individual should stop using hair dyes altogether. This is the only safe option but if the individual developed cross-sensitivity to some of the other chemicals, he/she might still have to avoid these or carefully monitor for symptoms that might occur from use.
  • Choose a safe alternative but since there is no safe product available, there might be a product that is safe for the individual. There are two routes that can be used – formal patch testing by an allergist and self-patch test.

Formal patch testing

This is performed by an allergist. The main chemicals that cause issues in hair dyes are recognized and available in patch test form. The doctor will test a range of these chemicals and will determine which ones the individual is sensitive to.

It is recommended to look for products that are free from the offending chemicals. Remember that there are drawbacks with this option such as referrals, waiting lists and limited number of chemicals tested.

Self-patch test

The individual can patch test a variety of products. This has the advantage that you test the whole product but if you react to some of them, the individual will know what component is causing the issue. A patch test is done by applying a small amount of dye solution either behind the ear or on the inner elbow and allow to dry and leave uncovered for 48 hours. If rashes or irritation develops in the area tested, the individual should not use the hair dye.

If the individual decides to use a hair dye, it is vital to perform a patch test just to be sure. A reaction can range from mild to severe, thus it is best to stay safe.

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