Our immune system keeps us healthy by fighting against anything harmful that enters our bodies – like bacteria and viruses. An allergen is something generally harmless that your immune system responds to like it’s a threat. You’ll usually get exposed to something a few times before that happens. But once you do, you’ll normally have that allergy for life.
Allergic reactions on your skin can often take a while to show – usually 24-48 hours after you came into contact with the allergen. You might hear this called ‘delayed hypersensitivity’, ‘type IV allergy’ or ‘contact allergy’. Most of the information here is about this kind of allergy, because most of our products can touch your skin in some way.