Patch Test Timing Before a Full-Head Colour
A client arrives at 4:00 pm on Friday for a full-head permanent colour. She mentions that she had a henna-based colour applied at another salon six weeks ago and that her scalp felt 'a bit itchy' afterwards. She also reports a reaction to a 'cheap' eyeliner years ago. She wants the colour done now because she has a wedding the next morning. Your salon policy requires a patch test 48 hours before any new colour product, but she is a regular client who has had the salon's colour before - just not this particular brand, which the salon switched to last month. She is impatient and says the wedding is important. The salon closes at 6:00 pm and the senior colourist has already left for the day.
1. Should you proceed with the colour today? Explain your reasoning, including what the patch test is actually for and what the henna history adds to the decision.
Read the worked answer
No - do not proceed today.
What the patch test does: It screens for an allergic (delayed hypersensitivity) reaction to a specific product formulation. It does not predict reactions to other products, and it is not a one-time lifetime clearance. Because the salon has changed brand, this client has not been tested against the new formulation, so the existing 'she's been coloured here before' history does not cover it.
Why the henna history matters: Henna itself is a plant dye, but 'henna-based' or 'black henna' products sold cheaply are frequently adulterated with paraphenylenediamine (PPD) to deepen the colour. Adulterated henna is a recognised cause of sensitisation to PPD, which is the same class of chemical found in many permanent oxidative colours. Her post-application itch is a warning sign, not a trivial detail, and the eyeliner reaction adds to a picture of possible contact sensitivity. Sensitisation can be silent until a later, larger exposure, so 'it only itched' does not mean the next exposure is safe.
The practical constraint: A valid patch test needs 48 hours, so it cannot be done at 4:00 pm Friday for a Saturday morning service. The senior colourist who could assess a reaction is gone.
What to offer instead: A patch test now, booked for a future colour; a non-oxidative, temporary option only if you can confirm it shares no suspect ingredients; or a referral to the client's GP or a dermatologist for advice. Document the conversation, the refusal, and the advice given. Explain the risk in plain terms - a severe reaction can involve facial swelling and, rarely, more generalised symptoms - and let her decide about the wedding with accurate information rather than pressure.
2. The client insists and offers to sign a waiver. How do you respond, and what would you document?
Read the worked answer
A waiver does not change the professional duty of care. You decline the service, politely and without judgement.
Reasoning:
- Consent forms and waivers are useful records of informed discussion, but they cannot make an unsafe service safe. Knowingly applying a product to a client with warning signs of sensitisation - an untested new brand plus a possible adulterated-henna history - is outside accepted practice regardless of what she signs.
- Insurance and salon policy typically exclude services performed against the salon's own patch-test rule, so the waiver would not protect you or the business.
- The pressure here is situational (a wedding), not a change in the clinical facts. The right response is to hold the line while solving her actual problem.
What to say: Acknowledge the deadline, explain that the risk is a reaction that could leave her worse off on the day, and offer alternatives - a patch test today so a future booking is clear, a styling service that does not involve oxidative colour, or a referral.
What to document:
- Date and time of the consultation.
- The products involved, including the new brand name and batch if known.
- The client's reported history: henna six weeks ago, scalp itch afterwards, eyeliner reaction.
- The salon patch-test policy and the reason it could not be met today.
- The advice given and the client's response, including that she offered a waiver and it was declined.
- The alternatives offered and whether she accepted any.
- Your name and signature.
Record facts, not opinions about the client's manner. If she becomes upset, keep the note neutral and factual.