Patch Test Before PMU: Consent Form, Waiting Time and Liability for Complications

A client comes in set on permanent makeup for her brows, wanting to do it "right away, because she doesn't have much time." The problem is that pigment deposited under the skin stays there for months or years, and an allergic reaction to its components might not appear until several days later. A patch test before PMU isn't a box-ticking formality, it's a real tool for protecting the client, and you as the person performing the treatment.

How a PMU patch test differs from one before henna or lamination

A standard patch test for brow henna or lamination checks the skin's reaction to a product applied on the surface. With PMU the situation is different, because the pigment goes under the skin and stays there permanently, so if an allergic reaction occurs, it involves a substance you can't just wash off.

• Pigment reactions tend to be more delayed than with surface products, sometimes only appearing several days after the test application, which is why the waiting time between the test and the actual treatment shouldn't be shortened.
• The test is usually done by depositing a small amount of pigment under the skin in a discreet spot, for example behind the ear or on the inner forearm, using the same technique you plan to use for the actual treatment.
• Observation covers not just redness, but also swelling, itching and changes in how the pigment itself looks under the skin, which can suggest the body doesn't tolerate a particular pigment formula.

How much time needs to pass between the test and the treatment

The standard recommendation is to wait 24 to 48 hours from the test to the start of the actual treatment, though for PMU many practitioners and pigment manufacturers recommend a longer observation period, even several days, given the possibility of a delayed reaction. Shortening that window under pressure from a client "in a rush" defeats the purpose of doing the test at all.

What a PMU consent form should include

Consent for permanent makeup needs to be more detailed than a standard cosmetic treatment consent, given the invasive and permanent nature of the procedure.

1. An explanation of the permanence of the result: the client should consciously confirm she understands that pigment placed under the skin remains there for an extended period, fading gradually, and that full removal requires separate, often costly procedures that aren't always fully effective.
2. A description of the healing process: information that full healing usually takes four to six weeks, during which the colour and shape may look different from the final result, and which activities the client should avoid during that time (pool, sauna, sun exposure).
3. Information about a touch-up session: most PMU treatments require an additional touch-up visit after a few weeks, which is worth clearly describing in the form, so the client isn't caught off guard by the need to come back and the additional cost.

• Confirmation of the patch test with a date, entered in the form, so the documentation clearly shows the time gap between the test and the actual treatment.
• A health interview with contraindications, signed separately or as part of the same document, covering chronic illnesses, pregnancy, medications affecting blood clotting.
• Consent for photo documentation, if you plan to take before-and-after photos for your portfolio, with a clear note on whether the client agrees to publication on social media or only for internal documentation.
• Information about the right to withdraw before the treatment starts, even after signing initial consent, if the client has second thoughts or raises new concerns at the last moment.

Liability for complications despite a test having been done

Doing a patch test significantly reduces the risk but doesn't eliminate it entirely. The body can react differently to a larger amount of pigment applied during the actual treatment than to the small test sample. That's why the documentation you collect matters even when, despite a negative test result, an allergic reaction still occurs.

• Documentation of the test and consent protects you by showing due diligence, that is, that you acted in line with industry standards by performing the test and informing the client about the risk before the complication occurred.
• A reaction despite a negative test doesn't automatically mean you're at fault, but it does require documented follow-up: reporting the incident, possibly referring the client to a doctor, keeping the batch number of the pigment used for further verification.

Frequently Asked Questions

Does the PMU patch test need to be repeated for every touch-up visit?

If you're using the same pigment as at the first treatment, and not much time has passed between visits, you typically don't repeat the test. If you're switching to a different pigment manufacturer, or a lot of time has passed since the first treatment, it's safer to run the test again.

What if a client has already had PMU with a different stylist and says "there was no reaction"?

That doesn't exempt you from running your own test, because you're using a different pigment, a different brand, or a different batch than the previous practitioner. An allergic reaction depends on the specific chemical composition, not on the general category of the treatment.

Does the PMU consent form have to be signed in person, or is an electronic signature enough?

An electronic form is acceptable, as long as the system confirms the client's identity and the date of signing, and the document can be printed or shown if needed, for example in the event of a dispute. Given how significant this consent is, many salons still choose a traditional handwritten signature on the day of the treatment.

How long should I keep PMU patch test and consent documentation?

Given the possibility of delayed health complaints, for invasive treatments like PMU it's worth keeping documentation longer than for standard cosmetic treatments, ideally for several years from the date of the treatment, in line with the general statute of limitations for civil claims.