Everything You Need to Know About Allergies: Symptoms, Causes, Diagnosis and Treatment.

Allergies occur when your immune system reacts to a foreign substance.

Allergy can affect nose, airway, sinuses, skin, and gastrointestinal tract. When you have allergies, your immune system makes antibodies that identify a particular allergen as harmful, even though it isn’t. When you come into contact with the allergen, your immune system’s reaction can inflame your skin, sinuses, airways or digestive system. The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency.

Allergic rhinitis, can cause:

• Sneezing
• Itching of the nose, eyes or roof of the mouth
• Runny, stuffy nose

Causes

An allergy starts when your immune system mistakes a normally harmless substance 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.

Common allergy triggers include:

• Airborne allergens, such as pollen, animal dander, dust mites and mold
• Certain foods, particularly peanuts, tree nuts, wheat, soy, fish, shellfish, eggs and milk
• Insect stings, such as from a bee or wasp
• Medications, particularly penicillin or penicillin-based antibiotics
• Latex or other substances you touch, which can cause allergic skin reactions

• Watery, red or swollen eyes (conjunctivitis)

Diagnosis

To evaluate whether you have an allergy, we generally

• Ask detailed questions about signs and symptoms
• Perform a physical exam
• Skin test. Your skin will be pricked with small amounts of the proteins found in common allergens. If you’re allergic, you’ll likely develop a raised bump (hive) at the test location on your skin.

Treatment

Allergy treatments include:

• Allergen avoidance.Once your allergen is identified with skin prick test measures to avoid the allergens will be explained. This is generally the most important step in preventing allergic reactions and reducing symptoms.
• Depending on your allergy, medications, in the form of pills or liquid, nasal sprays, or eyedrops.can help reduce your immune system reaction and ease symptoms
• For severe allergies or allergies not completely relieved by other treatment, we recommend allergen immunotherapy. This treatment involves a series of injections of purified allergen extracts, usually given over a period of a few years. Another form of immunotherapy is a tablet that’s placed under the tongue (sublingual) until it dissolves.
• Emergency epinephrine.If you have a severe allergy, you might need to carry an emergency epinephrine shot at all times. Given for severe allergic reactions, an epinephrine can reduce symptoms until you get emergency treatment.