“In season”: Are mould allergies seasonal?

With pollen allergies such as hay fever grabbing most of the headlines, many people might think that all environmental allergies are seasonal – but what about mould allergy: Is this seasonal too? Well, yes and no – it’s not quite that simple, read on to find out more!

Symptoms of a mould allergy

There’s no getting away from mould: there are over 100,000 species ¹ which can grow almost anywhere if there is enough moisture.² It can be found both inside and outside the house, growing on a variety of surfaces.³ The symptoms of mould allergies are similar to other airborne allergies and include a stuffy/runny nose, sneezing, itchy eyes and in severe cases, breathing difficulties.⁴

Symptoms such as these occur because the immune systems of people with mould allergies ‘over react’ to spores they breathe in. ⁴

You can read more about the body’s allergy response here. You can also find out about the different types of allergies people can have, as well as the best way to overcome the daily lifestyle challenges these allergies present.

Indoor mould is a problem that could grow

Mould is a common problem in houses: in one study almost a quarter of people reported that they had mould in their property. ⁵ Unfortunately, this figure may grow – the increase in energy bills in the UK, could mean colder homes and less ventilation which lead to increasing condensation and therefore more mould.⁶ It is important to remember that indoor mould can be found in any building, not just homes; this includes offices too.⁷

Either way, regardless of whether they are home or office, buildings which are susceptible to dampness are also susceptible to mould. This dampness can result from problems within the building such as leaky pipes/roofs or external sources like rainwater and flooding.^3,8 Prolonged dampness of materials in the building provide the breeding ground for mould.⁸

So just how does mould get into homes and offices in the first place? Mould can access buildings through open doorways, windows, vents, and air conditioning systems.³ Mould in the outside air can enter buildings via a person’s clothing or their pets.³ Mould spores start growing any time they find a place with the right amount of moisture.³

Some of the most common indoor moulds include Cladosporium, Penicillium, and Aspergillus.^3,9 In addition to causing allergies themselves, some of these moulds can also produce toxins which can cause additional health problems in their own right.⁹ We recommend consulting an expert if you find mould in your home or in a place you spend a lot of time in – such as an office.

So coming back to the original question…

Are mould allergies seasonal? Well, in a sense they are not as mould is present all year round.¹⁰ Whereas, in another sense they are, as the levels of most mould types are higher in certain seasons (late summer and autumn) than in others.¹⁰ So, the answer could be yes and no.

How to manage mould allergies

Luckily, there’s lots you can do to stop mould allergies becoming a problem and we have some suggestions below.

1. Minimise exposure:

The first thing to do is to reduce or avoid exposure to mould wherever possible and practical. Keeping windows and doors closed, regularly inspecting for/and cleaning up, any visible mould, taking your shoes off at the door, as well as installing air filters in the home can all help. You can also remove places where mould can grow before it gets a chance, for example; storage items from damp bedrooms or bathrooms.

2. Reduce the possibility of damp and humidity:

Simple steps such as opening a window or turning on a fan when you shower can prevent the build up of damp, as can using a dehumidifier.

3. Regularly cleaning places where mould can grow:

These areas include fridges and bathrooms.

4. Being extra careful with older buildings:

Look out for, and repair, any faults on a regular basis. For example, finding and fixing any leaks as soon as possible is important.

5. Taking medications:

Antihistamines such as Allevia® can go a long way in reducing any mould allergy symptoms you might experience. Allevia contains fexofenadine for the symptomatic relief of allergic rhinitis. Always read the label. A health professional can help with identifying exactly which types of mould you are sensitive to and prepare a treatment plan. In any case, if you are experiencing serious allergy symptoms, you should always see a health professional.

MAT-XU-2301669 V1.0 (May 2023)

References

Terr AI. Sick Building Syndrome: is mould the cause? Med Mycol. 2009;47 Suppl 1:S217-22.
University of Minnesota Extension. Dealing with and preventing mold in your home. Available at: https://extension.umn.edu/moisture-and-mold-indoors/dealing-and-preventing-mold-your-home Accessed March 2023.
Centers for disease control and prevention. Basic Facts about Mold and Dampness. Available at: https://www.cdc.gov/mold/faqs.htm#:~:text=Mold%20is%20found%20both%20indoors,can%20and%20be%20carried%20indoors Accessed March 2023.
Mayo Clinic. Mold Allergy available at: https://www.mayoclinic.org/diseases-conditions/mold-allergy/symptoms-causes/syc-20351519#:~:text=If%20you%20have%20a%20mold,breathing%20and%20other%20airway%20symptoms. Accessed March 2023.
The Independent. More than a fifth of UK homes are suffering from damp. Available at: https://www.independent.co.uk/property/uk-homes-damp-fix-solution-b2270560.html Accessed March 2023.
The Times. Why higher energy bills could lead to a rise in damp and mould. Available at: https://www.thetimes.co.uk/article/why-higher-energy-bills-could-lead-to-a-rise-in-damp-and-mould-sc0lwmvlp Accessed March 2023.
Ca.gov. Molds in indoor workplaces. Available at: https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/OHB/HESIS/CDPH%20Document%20Library/molds.pdf Accessed: March 2023.
Centers for disease control and prevention. Indoor environmental quality. Available at: https://www.cdc.gov/niosh/topics/indoorenv/mold.html Accessed: March 2023.
Bennett JW, Klich M. Mycotoxins. Clin Microbiol Rev. 2003;16(3):497-516.
University Hospitals Coventry & Warwickshire. Moulds and spores avoidance. Available at: https://www.uhcw.nhs.uk/download/clientfiles/files/Patient%20Information%20Leaflets/Women%20and%20Children_s/Paediatrics/Allergy%20-%20Moulds%20and%20spores%20avoidance.pdf Accessed March 2023.
University of Worcester. What are fungal spores? Available at: https://www.worcester.ac.uk/about/academic-schools/school-of-science-and-the-environment/science-and-the-environment-research/national-pollen-and-aerobiology-research-unit/What-are-fungal-spores.aspx#:~:text=Cladosporium%20and%20Tilletiopsis%20can%20start,and%20continues%20until%20late%20September. Accessed March 2023.

This article is not a substitute for medical advice. Allevia should be used as directed according to the product label. If you suspect that you have allergies, consult with your doctor or pharmacist. Only they can make a proper diagnosis.