California Cosmetology Written ExamClient Consultation and AnalysisMedium
A cosmetologist performs a predisposition patch test 48 hours before a scheduled aniline-derivative color service. After 48 hours, the test site shows no redness, swelling, itching, or irritation. What does this result indicate?
- AThe client needs a second patch test on the scalp before proceeding
- BThe test was performed incorrectly and must be repeated
- CThe test is negative, and the color service may proceed as planned
- DThe client is allergic and the service must be canceled
Show answer & explanationAnswer & explanation
Correct answer: C. The test is negative, and the color service may proceed as planned
A negative patch test result—meaning no visible reaction such as redness, swelling, or itching after 24-48 hours—indicates the client is not allergic to the tested product, and the aniline-derivative color service may proceed as planned.
Why the other options are wrong
- A. A single properly performed patch test is sufficient; a second test is not routinely required.
- B. A clean test site after the proper waiting period is a valid, correctly performed negative result.
- D. An allergic reaction requires visible symptoms like redness or swelling, which are absent here.
Negative Patch Test Result
A negative patch test shows no skin reaction after 24-48 hours, indicating the client is not sensitized to the product and the color service may proceed.
- Required before every new aniline-derivative color application
- Test site checked after 24-48 hours
- No redness/itching/swelling = negative = safe to proceed
Memory trick: 'Clear skin, clear to go' — no reaction means proceed.