Disha L, a Mumbai-based homemaker and mother of two, has been obsessed about cleaning all carpets, curtains and beddings, and generally keeping her house dust-free over the past two years — ever since her son was diagnosed with house dust mite allergy.
“The sight of dust gathering in any part of the living room scares me,” says Disha, who calls herself a paranoid mother because of the continuous efforts she makes to ensure that her 12-year-old son does not get an allergic reaction again. “I keep watching for triggering signs such as runny nose and wheezing in my son.”
This allergy occurs as a reaction to microscopic dust-mite allergens that commonly live in household dust. “It is also known as house dust allergy,” says a recent publication on house dust mites documented by the National Institute of Health, US. “It is sensitization and an allergic reaction to the droppings of the dust mites. The droppings are an indoor aeroallergen, which upon inhalation trigger the allergic reaction.”
According to Dr Pavan Yadav, lead consultant, interventional pulmonology and lung transplantation, Aster RV Hospital, Bengaluru, dust mite allergies can start from the nose, throat and go all the way to the lungs. “Nasal allergies have upper respiratory symptoms,” says Dr Yadav. “Some also develop lower respiratory symptoms with bronchial asthma such as cough, wheezing, breathlessness and chest pain.
“The most common source of dust mite allergy would be fabrics such as pillow covers, bedsheets, carpets, sofa covers. To get rid of the mites, we suggest that all such fabrics to be washed and sun-dried at least once a week — especially the pillow covers and bedsheets that are used for long hours.”
Dr Yatin Dholakia, a pulmonologist from Mumbai, says house dust mite allergy is one of the most common allergies. Mostly, it affects the upper respiratory tract (nose and the nasopharynx, which is throat’s top portion). “It can occur in anyone and at any time, especially in those who have atopic diathesis (having predisposition to allergy) and those who have high levels of IgE (immunoglobulins, a type of antibodies),” says Dr Dholakia. The onset of the allergy can be seen in childhood itself and it can be hereditary too.
“Wherever there is dust, these mites thrive on beddings, human dead skin, pet dead skin,” he says. “When people are exposed to allergens, it leads to allergic reaction. If it’s severe, it can lead to asthmatic attacks.”
Dust mite allergy
While skin prick tests are available to pinpoint a particular allergen causing the allergy, they are not done in all cases. “Most people, over 70 per cent of them who have these symptoms, do not undergo allergy tests,” says Dr Dholakia. “As currently available medicines are effective, allergy testing is not always done.”
In the absence of a cure for dust mite allergy, there can only be reduction of symptoms and frequency of allergic reactions, says Dr Dholakia. “Depending on the dust mite allergy symptoms seen, doctors prescribe medicines like antihistamines, nasal decongestants and steroids if they are severe,” he says. “For those suffering from asthma, inhalers are prescribed. Within one or two days, the symptoms reduce in most cases.”
Apart from medicines, non-pharmaceutical interventions also play a major role in preventing the triggering of allergies. “Non-pharmacological interventions — like vacuum cleaning, avoiding lot of carpets and cushions in the house, frequent changing pillow covers and beddings, using air purifiers and dehumidifiers — can help avoid the accumulation of dust,” says Dr Dholakia.
“I had no clue I had this allergy till three years ago when I had to undergo a test,” says Bengaluru-based Chethana Rakshit, 38, who is allergic to house dust mites. “My mornings were not easy, with continuous sneezing, and I developed wheezing too. Once it was diagnosed as dust mite allergy, all carpets were removed from the house and we changed the curtains. We mop the home twice and all corners are cleaned thoroughly. While this helped, I continue to use a nasal spray.” She also gets an itchy skin and rashes.
Dust mite allergy treatment
“Civic infrastructure work in a city further aggravates symptoms of dust mite allergy cases,” says Dr Dholakia. “With many roads being dug up in Mumbai, levels of suspended particulate matter (SPM, microscopic particles suspended in the air) are increasing, aggravating the symptoms of people who have allergy, as the dust settles in the home finally.”
Though the allergy is seen across age groups, it usually starts during childhood due to exposure to dust.
Dr Yadav says an allergy test is conducted in cases where people have a difficult-to-treat asthma and do not respond to basic empirical therapies such as antihistamines and inhalers. “The most common culprit in these tests are house dust mites,” he says. “We also do sublingual immunotherapy (SLIT), where small doses of an allergen are put under the tongue. This helps in improving the tolerance to dust mites and reduces symptoms. SLIT has shown very good response in those with asthma.”