How climate worsens allergies – and what you can do

Posted on 1 April 2021

Dr Pieter de Waal, a paediatrician and allergologist at Mediclinic Bloemfontein, explains why we should care.

Global warming and climate change brings immediate and long-term health threats to everyone, especially allergy sufferers. According to the World Health Organization (WHO), climate change will be the cause of 250 000 additional deaths per year between 2030 and 2050. The rise in air pollutants, aeroallergens, and toxic gases pose an immediate and long-term threat – especially to respiratory allergy sufferers.

Asthma, hay fever and other respiratory problems are substantially exacerbated by global warming and climate change. An increase in surface temperatures promotes pollination of plants (grass, trees, flowers or weeds) and extends the pollinating season by prolonging spring. This causes respiratory allergy sufferers to be exposed to high aeroallergen loads for extended periods. In South Africa, grasses that cause pollen include rye, Bermuda, and wild oat. Trees (including plane, cypress and oak) and weeds (such as plantain and daisy) also affect allergy sufferers.

Some asthmatics are also susceptible to acute asthma exacerbations, especially due to increased levels of pollen during periods of heavy rain. This condition is known as “thunderstorm asthma”. Wind carries pollens for longer distances and increases aeroallergen levels. Long, dry seasons with sudden onsets of heavy thunderstorms and wind, especially in inland areas like the Free State, make asthmatics more susceptible to potentially life-threatening acute asthma attacks. Outdoor CO2 and other noxious gases can act as airway irritants, worsening respiratory airway allergies. An increase in indoor humidity and temperatures also influence the air inside our homes, favouring an increase in house dust mites, cockroaches, and mould allergens. Unfortunately, in South Africa, asthma and other respiratory allergies are still underdiagnosed and poorly managed, especially in rural parts of the country. Compared to first world countries, South African asthma sufferers are therefore at greater risk.

8 ways to protect yourself

  1. Advocate for the global reduction of energy consumption and waste production. Leaving an industrial low-carbon footprint is a priority. The climate change health threat is especially dangerous for generations to come.
  2. Make sure you use your allergy and asthma medication daily, as prescribed by your doctor. Allergy medication should be used as preventative, rather than curative treatment. Don’t stop your allergy medication when you’re better.
  3. Get an allergy test. Know your allergens – this will allow you to avoid them, if possible. Allergen avoidance strategies and commercial allergen reduction devices (such as air purifiers) are expensive and may not be helpful for your particular allergy. Consult with a specialist before you buy these.
  4. Wear glasses to protect your eyes. Allergen-protective mouth masks protect against inhalant allergens.
  5. Use electronic resources, specifically websites tailored to South African allergy sufferers. You can find valuable information on pollen and other allergies at
  6. South Africa is now fortunate to have pollen monitoring in all major cities. Pollen calendars are available at This means you can identify your specific “problem” times of the year and start your anti-allergy medication in advance.
  7. Ask your doctor to provide you with an “allergy action plan” that provides written information on how to recognise your allergy symptoms and when to take your medication.
  8. Know how to use your asthma inhaler devices and nasal sprays for hay fever. Incorrect technique prevents them from releasing the medication effectively.

Published in Healthy Life

In the interest of our patients, in accordance with SA law and our commitment to expertise, Mediclinic cannot subscribe to the practice of online diagnosis. Please consult a medical professional for specific medical advice. If you have any major concerns, please see your doctor for an assessment. If you have any cause for concern, your GP will be able to direct you to the appropriate specialists.