Allergens

Substances which are typically harmless for the majority of people, but in some individuals can produce allergic reactions of a varying nature (asthma, hives, etc.). An allergic person can come into contact with allergens in many ways, and the body responds accordingly: if the allergen has been breathed in then there will probably be respiratory symptoms, if it has been touched it will respond with skin inflammation. Allergens are contained in mixtures of synthetic perfumes and in essential oils.