How heatwaves and pollen grains are fuelling health issues

Even as the India Meteorological Department (IMD) warned about the heat wave across the Southern Peninsula of the country, people living in the states of Telangana and Andhra Pradesh are suffering from allergic reactions to pollen grains, causing allergic rhinitis commonly known as hay fever.

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The hay fever

Hay fever is an allergic reaction to environmental allergens such as pollens, dust mites, moulds, and animal dander. It is a common allergic condition that affects up to 1 in 5 people at some point.

“When individuals with hay fever come into contact with allergens like pollen, their immune system produces antibodies that trigger the release of chemicals like histamine, leading to symptoms such as a runny nose, itchy eyes, congestion, sneezing, and sinus pressure,” said Hyderabad based physician Dr Shweta Shivdhar.

Symptoms of hay fever can include a runny nose, nasal stuffiness, watery and itchy eyes, sneezing, coughing, itchy nose or throat, postnasal drip, allergic shiners (swollen skin under the eyes), fatigue, and poor sleep quality.

Dr Shweta added that not only pollen but heat also is causing sickness in people.

“Cases of fever lasting two to three days and colds are becoming more common. These cases are often characterised by high temperatures, typically reaching 102 F, and may also show a decrease in platelet levels,” said Dr Shweta.

Heatwave and pollen

Pollen production is directly influenced by temperature. Warmer temperatures during a heatwave can accelerate the growth and development of plants, including the reproductive processes responsible for pollen production.

Higher temperatures can stimulate plants to produce more flowers, increasing pollen production.

High temperatures can change the structure of biomolecules, such as DNA, RNA, proteins, and lipids, which could affect basic metabolic processes like translation, photosynthesis, respiration, and redox regulation.

Plants may produce and release more pollen in response to the warm and dry conditions, especially if there has been a drought preceding the heatwave.

Pollen is a common trigger for allergic reactions, particularly for those with hay fever (allergic rhinitis) or other pollen allergies.

Inhaling pollen can irritate the nasal passages, throat, and eyes, leading to sneezing, runny or stuffy nose, itchy and watery eyes, and throat irritation.

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Eye problems

The heatwave conditions can result not only in sneezing or other respiratory illnesses but also in allergic reactions in the eyes, causing redness and itching.

“The allergic reactions in the eyes usually occur during spring and early summer. There are many reasons for this. One reason is the increase in dust at night following the drying up of soil and windy conditions. Dust can fly and get into the eye, causing allergic reactions,” senior ophthalmologist at MGM Hospital in Chennai Dr Ravindra Mohan told South First.

He points out that the release of pollen by many plants can also cause this.

“For instance, in Bengaluru, the presence of Parthenium pollen in significantly high amounts is a common cause of allergic rhinitis,” said Dr Mohan.

People with pre-existing conditions such as wheezing and sneezing due to dust also tend to experience worsening symptoms during the season.

Another significant factor is sweating. “If water consumption is inadequate, tear production can decrease. The ambient temperature outside affects tear secretion; hotter temperatures coupled with inadequate hydration can lead to a relative dryness or dehydration in the body, reducing tear secretion and making it easier for allergies to set in,” said Dr Mohan.

Tears normally wash away particles like dust or smoke, preventing allergic reactions.

“However, allergies can flare up in the absence of adequate tears. Increased allergy can lead to dryness because the glands on the eyes responsible for tear production may produce fewer tears when inflamed due to allergy. This forms a vicious cycle of allergy and dryness,” said Dr Mohan.

The seasonal issue

Dr Mohan said the doctors tend to see a lot of patients with dryness and allergies during these seasons.

On asking whether there has been an increase in allergies, he said: “Possibly, Yes. Especially in cities, it’s quite common; almost every other patient has allergic findings.”

He said pharmacists pointed out an increased sale of anti-allergic drugs and lubricants during this season due to more people experiencing allergies.

“However, I want to emphasise the importance of avoiding self-medication. Sometimes, when we visit a drugstore and describe our symptoms, they may provide medication, but not all places may be very responsible. In some cases, they may even give steroid drugs without proper medical supervision,” said Dr Mohan.

Using steroids without medical supervision, especially for an extended period, can lead to complications such as glaucoma and even cataract formation, he said.

“Steroids are powerful, and while they provide immense relief, they are not like regular anti-allergic or lubricating drops. Some people may think it’s okay to use them occasionally, but if the eye is sensitive to steroids, it can increase pressure and cause irreparable vision loss,” said Dr M0han.

“So, it’s essential to consult your local ophthalmologist to ensure proper treatment and follow these general measures. General measures are beneficial for everyone,” he added.

The precautions

Dr Shweta said that managing allergic rhinitis during a heat wave requires a combination of preventive measures and symptom management techniques.

“Pollen levels are usually higher in the morning and early evening. Try to stay indoors during these times to minimise exposure to allergens. Keep windows and doors closed to prevent pollen from entering your home. Use air conditioning with a clean filter to keep indoor air clean,” said Dr Shweta.

She asks people to drink plenty of water to stay hydrated, as dehydration can worsen allergy symptoms and if possible, limit outdoor activities, especially on windy days when pollen is more likely to be dispersed.

Dr Mohan suggested that if one tends to experience allergies during this season, it is better to use large protective glasses.

“These glasses should be larger than small dark goggles, providing better coverage to reduce the amount of dust, smoke, and small pollen entering the eyes,” said Dr Mohan.

He added that people should ensure adequate hydration by drinking plenty of fluids, aiming for 2 to 3 litres of water daily.

“It’s helpful to keep a water source nearby, whether at the office or elsewhere, to remind yourself to stay hydrated with regular water breaks,” he said.

“Wash your face with soap and water when you return home from work, school, or college. Additionally, combing or dry-mopping your hair can help reduce the amount of allergens such as dust, smoke, or pollen that may have accumulated during the day. By doing this, you can prevent allergens from entering your eyes throughout the night,” said Dr Mohan.

“It’s a good habit, especially for those prone to allergies, to wash their eyes with cold drinking water. In many places in India, tap water may not be suitable for this purpose due to concerns about its quality. Cold water can help alleviate allergy symptoms such as itching and it could wash away any allergens that may be causing issues,” he added.

“After washing your hands with soap and water, you can splash cold water onto your eyes for further relief,” Dr Mohan opined.

(Edited by Muhammed Fazil)