What is an allergy?

An allergy is best defined as a reaction due to sensitivity to normally harmless substances. This occurs when the immune system mistakenly identifies a substance, known as an allergen, as a threat and mounts an inappropriate response. Common allergens can include pollen, pet dander, certain foods, and insect stings. This response can lead to symptoms ranging from mild irritation, such as sneezing and itching, to more severe reactions, like anaphylaxis.

Understanding this concept is crucial, especially in fields like cosmetology and manicurist services, where exposure to various products might trigger allergic reactions in clients. Recognizing the difference between allergens and other medical conditions, such as infections or contagious diseases, is important for providing safe and effective services.