Skin problems and cosmetics Allergies

A patch test is a method for investigating what substance causes skin irritation.
The type of patch test performed most often at dermatology clinics is a method called the ""closed patch test.""
First, the substance suspected of causing the irritation is applied to a flat part of the back, with a bandage placed over it, for two days.
During that time, wiping the body is fine, but bathing is not allowed.
Then the bandage is removed, and the reaction is observed 2 days, 3 days, and 1 week later.
While we tend to expect an immediate reaction if there is an allergen, it sometimes takes several days for the antigen-antibody reaction that triggers the allergy to establish itself inside the body.
That's why the reaction is checked three times over a longer period.

The inner arm, where skin is soft, is a good place to get an accurate response to an allergen.
With clean hands, apply the cosmetic item (about the size of a 100 yen coin) on 3 places, as indicated in the illustration.
*When using things like face wash, soap, or shampoo, first lather it up with water, then apply it to the skin, leave on 1-2 minutes, and rinse.
Bathing is fine during this time. Just be sure not to rub hard with a cleanser, etc., on the inner arm where the cosmetic is applied. Wait and see for about 4 days, and if there is no problem, you can use it on the face.