An allergy is an exaggerated
Allergic conjunctivitis Allergic reactions Allergy testing Allergy to mold, dander, dust Atopic dermatitis(eczema) Contact dermatitis Drug allergies Food allergies Hay fever(allergic rhinitis)
Causes, incidence, and risk factors
Allergies are relatively common. Both genetics and environmental factors play a role.
The immune system normally protects the body against harmful substances, such as bacteria and viruses. It also reacts to foreign substances called
But in a person with allergies, the immune response is oversensitive. When it recognizes an allergen, it releases chemicals such as histamines. which fight off the allergen. This causes
Common allergens include pollen, mold, pet dander, and dust. Food and drug allergies are common. Allergic reactions can also be caused by
Some people have allergy-like reactions to hot or cold temperatures, sunlight, or other environmental triggers. Sometimes, friction (rubbing or roughly stroking the skin) will cause symptoms.
A specific allergy is not usually passed down through families (inherited). However, if both your parents have allergies, you are likely to have allergies. The chance is greater if your mother has allergies.
Allergies may make certain medical conditions such as sinus problems,