3.4 Adverse and Allergic Reactions: Recognition, Patch Tests and Correct Action
Key Takeaways
Irritant contact dermatitis is direct chemical damage that can appear on anyone's first exposure, while allergic contact dermatitis follows sensitization and usually appears 24 to 72 hours after re-exposure.
Signs of an adverse reaction include redness, itching, burning, swelling, hives, blisters or weeping; swelling of the face, lips or tongue or trouble breathing is an emergency that calls for 911.
The correct action is to stop the service, remove the product with cool running water, perform no further chemical service, and refer the client to a physician.
Minnesota requires licensees to offer a patch test whenever the manufacturer recommends one and to tell the client about the risk of adverse reactions (Minn. R. 2105.0375, subp. 7, item F).
Paraphenylenediamine (PPD) in permanent hair color, methacrylate nail monomers and fragrances are among the most common allergens in salon services.
Why this section matters
Under Safety and Infection Control, the general theory exam lists the patch test (01.A.6) and adverse or allergic reactions: signs and symptoms, and correct action (01.E). The written practical lists patch tests in color, perm and relaxer procedures. Expect scenario questions: "During a color service the client's scalp begins to itch and swell. What should the cosmetologist do first?"
Two kinds of reactions
| Feature | Irritant contact dermatitis | Allergic contact dermatitis |
|---|---|---|
| Cause | Direct damage to the skin by a harsh or strong chemical (high pH, solvents, frequent wet work) | Immune response to an allergen after the body has been sensitized |
| Who reacts | Anyone, if the exposure is strong or repeated enough | Only sensitized people, even at low amounts |
| First exposure | Can react on the first exposure | Usually no reaction until a later exposure |
| Timing | Minutes to hours | Typically 24 to 72 hours after exposure (delayed) |
| Typical look | Redness, dryness, cracking, burning, mostly where the product touched | Itching, redness, swelling, blisters; can spread beyond the contact area |
| Salon examples | Lightener or relaxer left too long, repeated hand washing, acetone | PPD in oxidative hair color, methacrylate nail monomers, glyceryl monothioglycolate perm solution, fragrance, nickel |
Sensitization is why a client who has colored her hair for years can suddenly react. Each exposure can increase sensitivity, which is why the FDA says to do the skin test before every coal-tar hair dye use and why nail technicians avoid skin contact with monomer and gel.
Immediate (hive-type) reactions
Some reactions appear within minutes: hives (wheals), itching and swelling. Latex gloves can cause this type of reaction in people allergic to latex proteins. The most serious form, anaphylaxis, can include swelling of the lips, tongue or throat, wheezing or difficulty breathing, dizziness or fainting. Anaphylaxis is a medical emergency.
Signs and symptoms to watch for
| Area | What you may see or hear |
|---|---|
| Skin or scalp | Redness, burning or stinging beyond normal tingling, itching, swelling, raised welts, blisters, weeping, peeling |
| Eyes and face | Puffy eyelids, watery or red eyes, facial swelling |
| Breathing | Coughing, wheezing, tightness in the chest or throat |
| General | Dizziness, nausea, faintness, sudden anxiety |
A client who says the product is "burning more than usual" is giving you an adverse-reaction warning. Do not wait for the processing time to end.
Correct action
- Stop the service immediately.
- Remove the product by rinsing thoroughly with cool running water; for the eyes, flush continuously for at least 15 minutes while holding the lids open. Do not try to neutralize a chemical with another chemical.
- Do not apply any further chemical (no toner, no neutralizer to "fix" it, no second product).
- Call 911 for swelling of the face, lips or tongue, difficulty breathing, fainting or a severe burn.
- Comfort and refer. Apply a cool compress if appropriate, and advise the client to see a physician. Do not diagnose or recommend medication.
- Document the product, batch number, formula, timing and what you observed on the client record so the client can tell the physician exactly what was used.
- Report. A client or licensee can report a cosmetic reaction to the FDA; under MoCRA the product's responsible person must report serious adverse events to the FDA within 15 business days.
- Do not repeat the product on that client. Future services need a different product and a negative patch test.
The predisposition (patch) test
A patch test, also called a predisposition test or skin test, checks for sensitivity to a product before a service. The FD&C Act requires coal-tar hair dye labels to give directions for a preliminary skin test, and Minnesota requires licensees to offer a patch test whenever the manufacturer recommends, advises or requires one, and to inform the client of the risk of adverse reactions (Minn. R. 2105.0375, subp. 7, item F(1)).
Procedure (hair color):
- Choose a test site behind the ear or in the inner fold of the elbow.
- Cleanse an area about the size of a quarter with mild soap and water and pat dry.
- Mix a small amount of the exact formula (color and developer) that will be used.
- Apply with a clean cotton swab and leave it uncovered and undisturbed for 24 to 48 hours, or as the manufacturer directs.
- Read the result. Negative: no change, so the service may proceed. Positive: redness, swelling, burning, itching, blisters or eruptions, so do not apply that product.
- Record the date, product, result and client's signature or acknowledgement on the record card.
Important
A negative patch test lowers the risk but does not guarantee the client cannot react during the service. Keep watching the skin and ask the client how it feels throughout processing.
Preventing reactions for yourself
- Wear gloves when mixing and applying chemicals and when handling disinfectant, and choose nitrile if you react to latex.
- Keep nail monomer, gel and adhesives off the skin, and never touch uncured product.
- Moisturize hands, dry them thoroughly and avoid unnecessary wet work.
- Read safety data sheets (Section 3.3), which list health effects and first aid.
- Report any recurring rash, cough or asthma symptoms to a physician; occupational sensitization tends to worsen with continued exposure.
Halfway through a permanent color service, a client says her scalp is itching and burning and you see redness spreading along the hairline. What should you do first?
Stop the service and rinse the color off with cool running water
Apply a toner to calm the scalp
Finish the processing time so the color develops evenly, then shampoo twice
Apply a protective base cream over the color
A longtime color client develops an itchy, swollen rash two days after her latest service, although she never reacted before. What best explains this?
A normal reaction that happens with every oxidative color
Irritant contact dermatitis from a single strong exposure to an overly alkaline formula
Allergic contact dermatitis after she became sensitized to an ingredient such as PPD
An infection carried by the color brush
Where is a predisposition (patch) test usually placed, and how long is it left before the service?
On the forehead, for 12 hours
On the back of the hand, left for one hour under a plastic cap
On the scalp at the crown, for 15 minutes
Behind the ear or inside the elbow, for 24 to 48 hours
Under Minnesota rules, what must a licensee do when a product's directions recommend a patch test?
Perform the service only after the client provides a physician's written approval
Offer the patch test and inform the client about the risk of adverse reactions
Use the product only on clients over age 18
Nothing, because patch tests are the client's responsibility
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