Allergens are substances that come from outside the body. Most allergens are substances that simply occur in nature. These substances are basically harmless. After entering the body (through nose, mouth or skin contact), they can cause allergic symptoms in sensitive people.
Allergens can appear in cosmetics, laundry detergents, and personal care products. Some people are allergic to perfumes and / or dyes that contain these products.
Many substances can cause a skin allergy. This happens more often with some substances than with others.
Common allergens are:
Metals (such as nickel and chromium)
Paraphenylenediamine (used in black hair dye and tattoos, among others)