Allergies are a common condition affecting more than one out of every 5 people. Allergies are an abnormal response of the immune system triggered by a typically harmless substance. This substance, such as pollen, mold or animal dander, is known as an allergen. When a person is exposed to an allergen, their bodies produce antibodies and release a variety of chemicals including histamine. Histamine is the main cause for most allergy symptoms. Most allergies are inherited. People with asthma are more likely to suffer from allergies. Since most allergens are found in the air, the reaction occurs in the eyes, nose and lungs. If the allergen is ingested, the reaction can occur in the mouth or stomach.
Most allergic reactions result in mild symptoms that include sneezing, runny nose, watery eyes, itching or rashes. Moderate or severe reactions, called anaphylaxis, are rare but can be life-threatening and cause abdominal pain, cramps, vomiting and dizziness. Bee stings, penicillin and peanuts can cause more serious reactions.
Allergies can be seasonal and only cause reactions during certain times of the year. This condition is known as allergic rhinitis or hay fever, and is usually caused by pollen and other allergens that are in the air from March until November. These allergies can be affected by the weather.
Allergy treatments are usually prescribed in the form of over-the-counter or prescription medication. Antihistamines prevent the reaction caused by the release of histamine and reduce symptoms. Decongestants unblock nasal passages and improve breathing. Nasal sprays keep the nasal passages clean and moist and limit the reaction to allergens. But the most effective treatment in relieving allergy symptoms is simply to avoid the allergen. Wearing sunglasses while outside and washing your hands frequently can help to keep you free of contamination.