Allergies

Allergies are a common chronic condition that occurs when the immune system reacts to a foreign substance—such as pollen, bee venom, pet dander, or certain foods—that doesn’t cause a reaction in most people. This article will delve into the types, causes, symptoms, diagnosis, treatment, and prevention of allergies.


Types of Allergies

  1. Food Allergies:

    • Common allergens include peanuts, tree nuts, shellfish, fish, milk, eggs, soy, and wheat.

    • Symptoms can range from mild (hives, stomach cramps) to severe (anaphylaxis).


  2. Seasonal Allergies (Hay Fever or Allergic Rhinitis):

    • Triggered by outdoor allergens like pollen from trees, grasses, and weeds.

    • Symptoms include sneezing, runny or stuffy nose, and itchy eyes.

  3. Pet Allergies:

    • Caused by proteins found in the skin cells, urine, and saliva of pets.

    • Symptoms include sneezing, runny or stuffy nose, and itchy or watery eyes.

  4. Dust Mite Allergies:

    • Caused by microscopic bugs living in household dust.

    • Symptoms include sneezing, runny or stuffy nose, and itchy or watery eyes.

  5. Insect Sting Allergies:

    • Caused by stings from bees, wasps, hornets, or ants.

    • Symptoms can include swelling, redness, and in severe cases, anaphylaxis.

  6. Drug Allergies:

    • Common drug allergens include penicillin and other antibiotics.

    • Symptoms can range from a rash to anaphylaxis.

  7. Latex Allergies:

    • Caused by latex found in gloves, balloons, and other products.

    • Symptoms can include hives, itching, and in severe cases, anaphylaxis.

Causes of Allergies


Allergies occur when the immune system produces antibodies known as Immunoglobulin E (IgE) in response to a substance that it mistakenly identifies as harmful. Upon subsequent exposure to the allergen, these antibodies trigger the release of chemicals like histamine, leading to allergy symptoms.

Symptoms of Allergies

Allergy symptoms vary depending on the allergen and can affect the airways, sinuses and nasal passages, skin, and digestive system. Common symptoms include:

  • Respiratory Symptoms: Sneezing, nasal congestion, runny nose, itchy or watery eyes, and coughing.

  • Skin Reactions: Hives, eczema, and itching.

  • Digestive Symptoms: Nausea, vomiting, diarrhea, and stomach cramps.

  • Severe Reactions: Anaphylaxis, a lifethreatening reaction that can cause airway constriction, shock, and severe drop in blood pressure.


Diagnosis

Diagnosing allergies involves a combination of medical history, physical examination, and specific tests:

  1. Skin Prick Test:

    • Small amount of potential allergens are picked into the skin to observe for reactions.

  2. Blood Tests:

    • Measures the level of IgE antibodies to specific allergens in the blood.

  3. Elimination Diet:

    • Removing suspected allergens from the diet and then gradually reintroducing them to identify the cause of symptoms.

Treatment


While there is no cure for allergies, treatments can help alleviate symptoms:

  1. Avoidance: Antihistamines, decongestants, corticosteroids, and leukotriene modifiers can help control symptoms.

  2. Medications: Antihistamines, decongestants, corticosteroids, and leukotriene modifiers can help control symptoms.

  3. Immunotherapy: Allergy shots or sublingual tablets can help desensitize the immune system to specific allergens over time.

  4. Emergency Epinephrine: Used to treat severe allergic reactions (anaphylaxis).

Prevention

Preventing allergies involves minimizing exposure to allergens:

  1. For Food Allergies: Read labels carefully, avoid crosscontamination, and inform others about your allergies.

  2. For Seasonal Allergies: Keep windows closed, use air conditioning, and stay indoors during high pollen counts.

  3. For Pet Allergies: Bathe pets regularly, keep them out of bedrooms, and use HEPA filters.

  4. For Dust Mite Allergies: Use allergyproof bed covers, wash bedding in hot water, and reduce indoor humidity.

  5. For Insect Sting Allergies: Avoid wearing bright colors, use insect repellent, and be cautious around outdoor eating areas.

Editorial History

Written By:

Nikita Kewalramani

Reviewed By:

Dr. Sachin Kadoo

MBBS, MD.

Last updated: July 29, 2024

References:

  1. Burks, A. W., Tang, M., Sicherer, S., Muraro, A., Eigenmann, P. A., Ebisawa, M., ... & Allen, K. (2012). ICON: food allergy. Journal of Allergy and Clinical Immunology, 129(4), 906-920. https://doi.org/10.1016/j.jaci.2012.02.001

  2. Pawankar, R., Canonica, G. W., Holgate, S. T., & Lockey, R. F. (2011). Allergic diseases and asthma: a major global health concern. Current Opinion in Allergy and Clinical Immunology, 11(5), 307-308. https://doi.org/10.1097/ACI.0b013e32834a8c3d

  3. Zuberbier, T., Lotvall, J., Simoens, S., Subramanian, S. V., & Church, M. K. (2014). Economic burden of inadequate management of allergic diseases in the European Union: a GA2LEN review. Allergy, 69(10), 1275-1279. https://doi.org/10.1111/all.12470

  4. Global Initiative for Asthma. (2020). Global strategy for asthma management and prevention. Available at: www.ginasthma.org