Skin allergy patch test is crucial before starting a hair colouring project with a client. Most people are allergic to ammonia, which is used in many of the hair colouring products. Some hair colouring products claim to be ammonia free or Paraphenylenediamine (PPD) free, but the reality is that they use substitutes of PPD that are even more dangerous and may cause an allergic contact dermatitis with itching and redness in the forehead. Some of the common substitutes include:

• Rodol, Orsin or Ursol
• Diamine Toluene Sulfates
• Benzenediamine

The affect may spread to the skin of the face as well as the whole body in severe cases. In some cases, this may affect some organs, besides causing contact urticaria, allergic contact dermatitis and anaphylactic shock.

SKIN ALLERGY PATCH TES

• To test whether a client is allergic to a hair colour, clean a small area behind their ear or inside of the elbow and then apply a small amount of colour and developer as per the directions. Allow it to dry.
• Ask the client to go home and monitor the area for allergy for two days.
• Follow-up with them after 48 hours to find the condition of the skin patch.

Although it's natural to have slight itching or sensitivity after a colour is applied to the skin, if the area burns or feels like itching so severely that it is unbearable, this means they are allergic to it.

Results

No irritation: If the patch test does not show any signs of allergic reactions to the hair colour, let the client know and go ahead with scheduling the colour appointment. Apply the colour as you do normally.

Mild to Moderate Irritation: If the client's patch test shows mild to moderate reactions, it is important to exercise caution. Let your client know that it is crucial for them to consult their doctor before proceeding with using any permanent hair colour.

Severe Burning, Irritation or Itching Sensation: If the skin patch test demonstrates severe signs of allergic reactions, the client must consult their physician. Let the client know that there are other alternatives in the form of non-permanent hair colour options, which do not have allergy causing ingredients.

Whenever a new client comes to you to get their hair coloured permanently, ask them clearly if they are sensitive to PPD's. If they are, non-permanent hair colouring options will be the best solution. However, if they are doubtful, it is best to do a patch test, irrespective of the hair colouring product you are using to be on the safe side.