Why are allergies on the rise and how can you prevent them?

An allergy is the excessive reaction of our body’s immune system to a substance that is harmless for most human beings. Our immune system is our primary protective mechanism against harmful invaders – bacteria, viruses and parasites. This system, developed over millions of years of evolution helps provide adequate protection to our bodies. But sometimes, our immune system may identify a harmless substance as harmful and can react strongly, causing harm to our own bodies.

Understanding respiratory allergies

Respiratory allergies are a reaction of our immune system against substances such as pollen, cold air, dander of pet animals, dust mites, exercise, fungal spores etc. Respiratory allergies manifest in mainly three ways: allergic rhinitis, which causes a runny nose and nose blockages; bronchial asthma, which causes cough and breathlessness and allergic conjunctivitis which causes itching, redness and watering of eyes.

Rising prevalence

The incidence and prevalence of respiratory allergies have been on the rise over the past century. Changing lifestyles and diets, including the consumption of processed and junk food, bidi and cigarette smoking, exposure to biomass fuel smoke, exposure to environmental pollution such as vehicle smoke and exposure to pesticides are some of the major drivers of the increase in respiratory allergies. About 35 million people in India suffer from bronchial asthma, but only 30% get a correct diagnosis. Only a few people develop respiratory allergies due to genetic predisposition; however, obesity is a major risk factor, and in many cases, obesity-related allergies are also difficult to control.

Identification and diagnosis

People with symptoms of respiratory allergies should consult a respiratory physician or an allergy clinic. A comprehensive analysis of the patient’s symptoms, history of exposure to trigger factors and history of recurrent symptoms with exposure provides enough clues towards the diagnosis of a respiratory allergy. Many times however, the immune system of a person with a respiratory allergy reacts against a variety of different innocuous stimuli, and so, it becomes difficult to pinpoint one trigger factor causing the person’s symptoms. However, simple tests like the skin prick test, blood tests of specific immnunoglublins can help the physician and patient to identify a major trigger factor, for instance, dust mites. A mere positive allergy skin test report though, is not enough to blame a particular antigen or trigger factor — the rest reports need to be correlated with exposure history and the patient’s symptoms by a trained respiratory physician to confirm the diagnosis.

Once a particular antigen correlating with a patient’s symptoms and exposure is identified, hyposensitisation with immunotherapy can be done for a few antigens. In immunotherapy, the same substance that causes the allergy, is introduced to the patient’s body in very low doses, gradually, in the form of a tablet or subcutaneous injection.

Avoiding allergies

Most respiratory allergies can be prevented by following few general lifestyle changes such as:

• Avoiding exposure to dust and pollution

• Avoiding cigarette and bidi smoking

• Switchingto LPG gas stoves for cooking instead of biomass fuel

• Daily walking and breathing exercises

• Adding more fruits and vegetables to the diet

• Avoiding junk food, too much oil and spices in food

• In case of obesity –decreasing body weight with daily exercise and a diet protocol

• Avoiding fungal growths at home by preventing water seepage in walls

• Vaccination against common respiratory pathogens like influenza and pneumococcal vaccines

What is anaphylaxis?

Anaphylaxis is a very severe form of an allergic reaction to a variety of substances such as bee stings, medications including particular antibiotics, latex, contrast agents used in imaging studies etc. Some people can have anaphylaxis with food items such as peanuts, prawns or mushrooms. During an anaphylaxis episode a person develops severe breathlessness, decrease in blood pressure and swelling of the lips and throat as well as skin lesions. Anaphylaxis is a medical emergency, and the person needs immediate help and treatment. It is very important for the person who had an anaphylaxis reaction to maintain and keep a list of substances he or she is allergic to. Avoidance of exposure to such drugs or food items is the best preventive strategy against anaphylaxis. However, to deal with cases of emergency , doctors sometimes train the patient and relatives to administer ready-prepared injections of epinephrine.

Staying healthy

Allergic diseases are on the rise. But a healthy life routine, daily exercise, balanced diet, avoiding obesity, taking respiratory vaccines and maintaining a list of substances a person is allergic to and avoiding them are the best strategies to prevent allergic disorders.

(Dr. Prince James is with the Department of Interventional Pulmonology and Respiratory Medicine, Naruvi Hospitals, Vellore. prince.j@naruvihospitals.com)