For lash glue patch testing, which site is commonly used?

• A. Behind the ear
• B. On the chin
• C. On the inside of the wrist
• D. On the sole of the foot

Answer: (A)

Patch testing lash glue means applying a tiny amount of adhesive to a small skin area to check for an allergic reaction before using it near the eyes. The most common site is behind the ear. This location is close enough to the eye-area skin to be representative, yet easy to observe and keep protected from accidental contact with the eyes. The skin behind the ear is thin and sensitive, so a reaction there will indicate how eyelid skin might respond, and it’s simple to monitor for redness, itching, or swelling over 24 to 48 hours.

The chin isn’t ideal because it’s further from where lash glue is applied and can be affected by movement or facial hair, making reactions harder to interpret. The inside of the wrist is another potential site in some patch tests, but it’s farther from the eye area and not as practical for lash glue testing. The sole of the foot has thicker skin and is far from the eyelid area, offering little relevance for eyelash adhesive sensitivities.