Call 999 immediately for breathing or swallowing difficulty, sudden mouth or throat swelling, collapse or severe dizziness. Do not delay emergency help to wash the dye out. For a mild reaction, stop using the dye and wash it out thoroughly with mild shampoo. Seek medical advice if symptoms worsen.
- Do first
- Stop the product and remove the dye
- Emergency
- Breathing difficulty or sudden mouth/throat swelling: 999
- Before colouring again
- Discuss the reaction and whether allergy assessment is needed
Should I wait for the processing time to finish?
No. If you think the dye is causing a reaction, stop using it and wash your hair and scalp thoroughly with mild shampoo. Tell the person applying it straight away rather than waiting to see whether the discomfort becomes severe.
Keep the packaging or product details so you can explain what was used. The priority is dealing with the reaction, not correcting the colour or adding another chemical product to complete the appointment.
Which symptoms need emergency help?
Call 999 if you develop trouble breathing or swallowing, sudden swelling of the lips, tongue, mouth or throat, collapse, or marked confusion or dizziness after a reaction. A serious allergic reaction is uncommon, but needs immediate medical care.
Do not wait for an online enquiry to be answered or drive yourself to A&E. Explain the symptoms and recent dye exposure to the emergency service, then follow the instructions you are given.
What if the reaction is limited to my skin?
A hair-dye reaction may cause local burning, itch, soreness, a rash or blisters, and symptoms can develop later rather than immediately. A pharmacist can advise on a mild skin reaction; see a GP if the symptoms worsen or are not settling.
Describe where it is happening, including the ears, eyelids or neck, and when the symptoms began. Avoid deciding that a delayed reaction cannot be related simply because your scalp felt comfortable during the colour appointment.
Does it mean I am allergic to every hair dye?
Not necessarily, but the cause should be assessed before choosing another product. PPD is one recognised hair-dye allergen, while other ingredients and irritation can also be involved. The name or shade alone is not enough to identify the culprit.
Tell a doctor about previous reactions to dye or black henna tattoos. Ask whether referral for medical patch testing is appropriate, and keep a record of the actual result rather than labelling every later symptom as the same allergy.
Is a negative home test a guarantee?
No. Follow product instructions, but do not treat a previous negative test or an uneventful earlier colour as a guarantee that another exposure is safe. A diagnosed allergy needs specific professional advice about avoidance and future options.
Do not deliberately retry a product that caused a reaction to prove what happened. A strand test of the finished hair colour and a medical investigation of a skin allergy answer different questions; ask for clarification if those are being confused.
A conversation starts with you.
You can ask us about the clinic without committing to treatment. A GP or dermatologist assessment comes first for unexplained patches, pain or inflammation; any later clinic conversation can take that advice into account.
Ask your questionSources & references
- NHS: hair dye reactions
- DermNet: paraphenylenediamine and hair dye allergy
This guide provides general information. It does not diagnose a hair or scalp condition or confirm suitability for treatment.