Allergy

Allergies are commonly classified into different types based on the organ or system affected and the allergens involved. The main categories include:

• Respiratory allergies, which often affect the nose, lungs, and eyes
• Food allergies, which are often associated with gastrointestinal, skin, and systemic symptoms
• Skin allergies
• Drug and chemical allergies
• Insect venom allergies, which are caused by bee or wasp stings
• Severe systemic reactions, specifically, anaphylaxis, which refers to severe, potentially fatal allergic reactions

Allergic reactions can affect multiple organs or systems, with symptoms ranging from mild discomfort to life-threatening complications including the following: 

• Nose: Symptoms include sneezing, itchy/runny/stuffy nose, breathing difficulties, and/or mouth breathing.
• Eyes: Symptoms include itchiness, swelling, and/or redness in the eyes and watery eyes.
• Mouth/throat: Common symptoms include tingling, swelling, or itching in the mouth, throat, or lips.
• Skin: Commonsymptoms include eczema (a skin condition causing dryness and itchiness), hives (itchy welts on the skin), and/or contact dermatitis (inflammation and rash resulting from a repeated exposure to an allergen).
• Lungs: Common symptoms include coughing, wheezing, chest tightness, shortness of breath, or asthma.
• Gastrointestinal issues: Common symptoms include diarrhoea, abdominal pain, nausea, vomiting, and weight loss.
• Anaphylaxis (multiple systems): Anaphylaxis requires immediate medical attention. It is generally classified as follows:
  • Mild anaphylaxis: Early symptoms include hives, accompanied or followed by tingling or itching around the mouth and swelling of the mouth or eyes.
  • Severe anaphylaxis: Severe anaphylaxis can progress to swelling of the mouth and throat, causing breathing difficulties, and lead to the blood pressure dropping dangerously low, abdominal pain, nausea, and vomiting. 

Allergies develop when the immune system reacts to normally harmless substances. Some of the common triggers include:

• Airborne allergens: Pollen, house dust mites, cockroaches, pets, and mould can trigger respiratory or eye-related allergies.
• Food allergens: Eating specific foods can cause symptoms that range from mild discomfort to serious, sometimes life-threatening reactions. The patient’s age often influences allergies to specific food types.
  • Infants and toddlers are more likely to develop a reaction to milk and eggs.
  • Children and adults are mostly allergic to foods such as peanuts, tree nuts, shellfish, milk, eggs, and certain fruits (e.g., specific berries) and vegetables (e.g., brinjal).
• Skin contact allergens: Substances such as nickel, latex, certain cosmetics, and detergents may cause skin allergies.
• Medications: Certain medications such as antibiotics (e.g., penicillin), aspirin, and pain killers, may cause allergies.
• Insect venom: The venom of certain insects such as bees, wasps, hornets, and ants can also cause severe allergic reactions, including anaphylaxis.

Diagnosing allergies usually involves going through your family history and history of past illness, conducting a physical examination, and performing specific tests to confirm the presence of an allergy. The right allergy test depends on your specific symptoms, medical history, and individual needs. 

• Skin prick test: A tiny amount of allergen extract is pricked into the upper layer of the skin, usually on the forearm. If a person is allergic to the substance, a small raised bump (called a wheal) surrounded by a red area will appear within 15‒20 minutes. It is a safe and painless test and is the gold standard for allergy testing all over the world.
• Intradermal Test: It is similar to the skin prick test but involves injecting a small amount of allergen under the skin. It is more sensitive but carries a higher risk of causing an allergic reaction.
• Blood test: A blood test can help detect allergen-specific antibodies, particularly in patients for whom a skin prick test is not possible. This test is often recommended for individuals who cannot stop medications, have sensitive skin, or are at risk of severe allergic reactions during testing. 

Treatments for allergies focus on managing symptoms and reducing exposure to allergens and depend on the type and severity of your allergy. Your doctor will guide you in choosing the most suitable approach for your condition. The main methods for allergy management are: 

• Avoidance: For some allergies, especially food-related ones, strict avoidance of the allergen is the most effective approach. This can prevent symptoms and remove the need for medications or further treatment.
• Medications: When avoiding allergens is not enough, medications can provide relief from symptoms. Fast-acting medicines such as epinephrine injections are administered for severe allergic reactions, such as anaphylaxis.
• Allergy shots (immunotherapy): Allergy shots gradually help increase your tolerance to allergens over time and are often recommended for severe allergies or persistent symptoms that last for more than three months a year. While these allergy shots do not cure allergies, they significantly reduce your immune system’s sensitivity to allergens, thus reducing the intensity of the symptoms.
   

Patients are advised to visit their doctors when they show one or more of the aforementioned symptoms, especially after the consumption of a specific food or the use of a specific product. Periodic testing and regular follow-up are generally recommended to accurately monitor and manage your allergies, ensuring better health and quality of life.

If you or your child experience symptoms of an allergy, it is important to consult a doctor for testing. If an allergy is confirmed, you may be referred to a specialist, such as an allergist, for long-term management. Allergies can also change over time; infants may outgrow allergies to milk and eggs as they age, while other allergies may become more severe.

If you suspect or are diagnosed with an allergy, it is important to consult with the right healthcare professional. The types of specialist to be approached often depend on the type of symptoms exhibited by you and the part of the body affected and include the following: 

• Allergist/Immunologist: This is the primary specialist for diagnosing and treating all types of allergies, including food, drug, insect, and environmental allergies. They also help in managing asthma and immune-related conditions.
• Dermatologist: If you exhibit skin-related symptoms, a dermatologist should be consulted alongside or instead of an allergist.
• Pulmonologists (chest specialists): Patients for whom respiratory issues, such as asthma, and other respiratory issues that worsen due to allergies, must seek the help of a pulmonologist.
• ENT Specialist (Ear, Nose, Throat doctor/Otolaryngologist): If you have chronic nasal allergies, sinus problems, or allergic rhinitis, an ENT specialist may provide targeted treatment.
• Ophthalmologist: An ophthalmologist should be consulted for eye-associated allergic symptoms, such as redness and swelling in the eye.
• Paediatrician: The paediatrician should be the first point of contact for children with allergies, who, in turn, may refer the child to an allergist for further care.