Patch testing should be performed in which region?

Patch testing should be performed in which region?

• A. On the lips
• B. Behind the ears
• C. On the eyelid
• D. On the cheek

Answer: (B)

Patch testing works best when you choose a site that is discreet, easy to access, and unlikely to be affected by daily products or movement, so the readout reflects a true allergic reaction rather than irritation or rubbing. The area behind the ear fits these needs well: it’s relatively clean, flat, and protected from direct sun and most facial cosmetics, making it easier to apply patches and monitor redness, swelling, or the test reaction over 48 to 72 hours. It also keeps patches out of the treatment field and away from the lips, eyelids, or cheeks, which are more sensitive and prone to irritation or confounding reactions. This is why the behind-the-ear region is the preferred spot for patch testing in PMU practice.

Patch testing works best when you choose a site that is discreet, easy to access, and unlikely to be affected by daily products or movement, so the readout reflects a true allergic reaction rather than irritation or rubbing. The area behind the ear fits these needs well: it’s relatively clean, flat, and protected from direct sun and most facial cosmetics, making it easier to apply patches and monitor redness, swelling, or the test reaction over 48 to 72 hours. It also keeps patches out of the treatment field and away from the lips, eyelids, or cheeks, which are more sensitive and prone to irritation or confounding reactions. This is why the behind-the-ear region is the preferred spot for patch testing in PMU practice.