Wisconsin Esthetics State Board Practice Test

What is defined as a substance that causes an allergy?

1. Allergen

2. Antigen

3. Pathogen

4. Toxin

The correct answer is: Allergen

An allergen is specifically defined as a substance that can trigger an allergic reaction in susceptible individuals. This could include a variety of substances such as pollen, pet dander, certain foods, or chemicals found in cosmetics and personal care products. When an allergen enters the body, the immune system may react by producing an antibody known as Immunoglobulin E (IgE), leading to symptoms that can range from mild to severe, such as itching, hives, swelling, or even anaphylaxis. The other terms listed refer to different types of substances that do not have the same specific definition as an allergen. An antigen is a broader term that pertains to any substance that can provoke an immune response, including allergens but also including foreign substances like bacteria or viruses. A pathogen specifically refers to microorganisms that cause disease, such as bacteria, viruses, or fungi. A toxin is a poisonous substance produced by living cells or organisms, which can cause harm or illness but is not specifically associated with allergic reactions. Therefore, an allergen distinctly identifies substances that provoke allergic responses, making it the correct choice in this context.