Sensitivity doesn’t necessarily trigger a body-wide immune system response. Perfume sensitivity, much more common, is a reaction to something that irritates your body.
These symptoms can last for weeks before they go away. This immune system response usually develops over a course of days and manifests as itchiness or a rash. Then, it releases an inflammatory reaction to help fight off the substance as if it’s a bacterial or viral invader. This means that your body identifies the ingredient in the perfume as a foreign substance. When you have allergies, your body has a specific immune system response to an ingredient or a chemical in the perfume that causes the reaction.
