In principle, almost everyone can develop an allergy to any substance. In case of an allergy the body’s immune system reacts allergic to a substance that gives no problems for many people. An allergic reaction can start locally and then it (immediately or after some time) spread all over the body. The number of allergies caused by cosmetic ingredients is very small.
We can distinguish four types of allergies. Two of them are predominant, and these are described below. When it comes to reactions to cosmetics, the last one is the most common.
The first type occurs immediately after exposure to a substance, already within a few minutes. The reaction does not occur at the first contact with the allergy causing substance, but only after repeated exposure. This type of reaction is very rare in substances with which you come into contact, such as cosmetics. Hay fever and dust mite allergies are common examples of this type of allergy. In the worst case, the situation is life-threatening (anaphylactic allergic reaction). This is usually the case with substances that enter your body, for example, a food, or a wasp sting.
The last type of reaction appears somewhat later after exposure to the substance. It is possible this form of allergy appears 24-72 hours after contact. Usually the allergic reaction caused by substances with which you come into contact (contact allergy), and the reaction is not life threatening. The most common delayed hypersensitivity reaction is eczema, associated with red, irritated, itchy skin. Allergic reactions after the use of cosmetics fall mostly in this category. In addition, nickel allergy is a common example.