Types of allergies
An allergy starts when your immune system mistakes a normally harmless substance (allergen) for a dangerous invader. The immune system then produces antibodies that remain on the alert for that particular allergen. When you’re exposed to the allergen again, these antibodies can release a number of immune system chemicals, such as histamine, that cause allergy symptoms.3
Nasal Allergies:
Nasal allergies (rhinitis) are caused when your body reacts to allergens e.g. dust mites, tree pollen, or animal dander. It is mostly a temporary condition, and in most people, it clears up after a few days. However, sometimes the inside of the nose becomes inflamed and the rhinitis can become chronic, meaning it is almost always present or recurs often.9
Skin allergies:
Skin allergies can be caused by a variety of factors. These include immune system disorders, medications, infections or any allergen that can trigger an allergic reaction. Some common allergens include dust, insect bites, pollen and latex gloves.10,11
Eczema:
Eczema (atopic dermatitis) is the most common skin condition, especially in children. It affects between 10 % to 20 % of children and 1 % to 3 % of adults. People with eczema often have a family history of allergies.4,10
Hives:
Hives (urticaria) are an inflammation of the skin triggered when the immune system releases histamine. This causes small blood vessels to leak which leads to swelling in the skin10.
Welts appear which can range in size from small spots to large blotches several centimeters in diameter. Hives are white itchy bumps which look and feel like insect bites. Hives can be triggered by exposure to certain foods, medications or other substances.6,12
Swelling beneath the surface of the skin:
Swelling beneath the surface of the skin (angioedema) is a reaction similar to hives that affects deeper layers of your skin. It most commonly appears around your eyes, cheeks or lips. Angioedema and hives can occur separately or at the same time. Angioedema can be triggered by environmental factors e.g. heat, cold, and sunlight. Certain types of food e.g. shellfish, peanuts or milk.6
In most cases, angioedema is harmless and don’t leave any lasting marks, even without treatment. However, serious angioedema can be life-threatening if swelling causes your throat or tongue to block your airway.6