Is asthma contagious?

What causes it and how can it be treated or managed?

Sunday, December 31, 2017

Dear Doctor,

What causes it and how can it be treated or managed? Jean

Dear Jean,

Bronchial asthma is a condition of inflammation of the airways (tubes that carry air) of the lungs, characterised by cough, wheezing and shortness of breath. It may be acute and intermittent or chronic. The basic underlying problem is closure of the airways of the lungs due to inflammation in response to some substance causing allergy.

Allergy is strongly linked to bronchial asthma. It can be to any substance present in the atmosphere. House dust, mite droppings and dust, fungal spores and pollens, are the most common substances identified as causing allergy and attacks of asthma. Asthma can also be caused by chemicals present in processed foods or in body/hair care products, food items, particularly protein containing as eggs, peanuts, and etcetera. Drugs, particularly non-steroidal anti-inflammatory (NSAIDS) ones like aspirin and ibuprofen, can trigger attacks of asthma. Mental stress and excess physical activity can induce or aggravate attacks of asthma in those prone to it.

Diagnosis is done by a complete blood count, which shows high level of eosinophils (white blood cells which indicate allergy). Eosinophils can also be demonstrated in the expectoration. Lung function tests show obstruction of the air ways, which is reversible after using a bronchodilator (medicine producing widening of the air ways). Allergy tests can be done to identify the allergy producing substances. But they can be done only when one is symptom free for at least 48 hours and does not need any medication.

Prevention lies in avoiding the allergy producing substance if possible. Using a mask to cover the nose on exposure to dust helps in preventing an attack. Regarding food substances, one can exclude a suspected substance for two to three days from their diet and then re-introduce again. If symptoms stop on removing that substance from diet and relapse again after using it, then that substance is definitely the offender causing attacks of asthma. Toilet products can similarly be tested.

Treatment consists of corticoids to reduce inflammation of the air ways and bronchodilators. In fact, first line treatment consists of using these drugs through inhalation via inhalers. These drugs are also available in injection and tablet forms and are used appropriately as per the severity of the condition. Severe attacks of asthma need urgent hospitalisation and can be fatal if untreated. As such asthma is not contagious.