Symptoms of mould allergy
Scientists think there could be more than a million species of fungi. So far they’ve only identified a small fraction of them; mushrooms and toadstools, yeasts, mildews and moulds. Of those, around 100 moulds have been linked to mould allergy symptoms. With so many unknown unknowns, the true number could be higher.
You may come across mould every day, everywhere you go, both indoors and out. Most of the time you won’t even know it’s in the air. Until it gives you an itchy throat, runny nose, watery eyes and other mould allergy symptoms. Let’s find out how to recognise the telltale signs – and how to manage allergic reactions to mould.
Common mould allergy symptoms
Breathing in mould allergens often triggers the allergic reaction. As with other respiratory allergies, many symptoms affect your nose and airways. You may feel it straight away or there could be a delay. For instance, nasal congestion and breathing problems can build up over time.
- Hay fever symptoms: a runny or stuffy nose, post-nasal drip and sneezing. Also known as seasonal allergic rhinitis
- Eye irritation: On the surface and inside your eyelids giving you red, watery, itchy eyes
- Lower respiratory symptoms: a cough, shortness of breath, tight chest and wheezing
- Skin reactions: Dry patches, eczema (atopic dermatitis)
Mould spores: Other allergic conditions and symptoms
High levels of mould exposure, often through work, can lead to hypersensitivity pneumonitis (HP). Farmer’s lung is a type of HP caused by mouldy hay. Symptoms include a cough, chest tightness, aches and chills, tiredness and losing weight. Humidifiers, heaters and central air-conditioning can also cause HP by spreading mould spores. There’s even a report of HP traced to a steamy sauna.
Some rare conditions involve both allergic and an inflammatory response to exposure to mould. Allergic bronchopulmonary aspergillosis can cause severe breathing problems. Allergic fungal sinusitis is inflammation of the sinuses.
Mould allergy symptoms from food
Eating certain foods can cause mild local symptoms if you have mould allergies. This is a cross-reaction known as oral allergy syndrome or pollen food syndrome. Foods linked to mould include:
- Mushroom
- Yeast
- Spinach
You might get itchy or swollen throat, lips, mouth or face but it’s usually mild. This allergic reaction happens because proteins in the food and the mould spores are very similar.
What causes my mould allergy symptoms?
It’s the mould spores. These self-contained seeds are even tinier than pollen grains. The mould releases them to float through the air looking for a damp spot to grow in. It’s just that sometimes you breathe them in instead. That can trigger mould allergy symptoms if your immune system decides the spores are a threat.
How long do symptoms of mould allergy last?
That can depend on whether your symptoms are caused by indoor or outdoor moulds. Most outdoor species tend to cause mould allergy symptoms in summer to early fall before going into hibernation when it gets cold.
But the world is warming and that seems to be lengthening the period that outdoor mould spores are in the air. Studies also suggest the quantity of spores released increases when CO2 levels are higher. These basic facts about climate change could extend the outdoor mould allergy season and make mould allergies more likely.
It’s a bit different for people allergic to indoor moulds. Fungi depend on humidity to grow so they love your kitchen, bathroom and basement. And they can give you symptoms year round.
Risk factors for mould allergy symptoms
- Outdoor conditions: You may already know to avoid damp woodland and piles of autumn leaves. Also the countryside during harvest. But it’s also a good idea to wear a dust mask in the garden during mould allergy season. Ideally, you’d get someone else to mow the lawn, as well as turn and spread your garden compost. Certain moulds love it.
- Raising the indoor mould count without realising: Coats and shoes can trap spores when mould counts are high. So quarantine them by the door. Rub pets down with an old towel. Other carriers of mould spores include damp logs brought in for the fire.
- A long DIY to-do list: Leaky roofs and rain gutters can create the ideal conditions for mould growth. Regularly clear out your gutters to drain standing water and fix any roof or plumbing issues. Clear flood damage too. Excessive moisture encourages rot.
- Hidden mould growth: Clean mould from neglected areas such as behind kitchen cupboards and around window frames and fridge seals where they trap mould spores. Fridge condensation coils too if you can get to them. Keep houseplant numbers to a minimum and change the soil regularly to stop mould growing freely.
- Poor ventilation: Cooking, washing and cleaning all make hot damp air. This can add to the humidity mould spores love. Close internal doors to stop it spreading round your home and use extractor fans to vent excess moisture. Open windows when the mould count is likely to be low.
- Geography: Your local climate can also have an effect on mould allergy symptoms. Get yourself a hygrometer to measure indoor humidity levels and aim for between 30% and 45%. Remember this can change over the course of a day so check again later. Lowering naturally high humidity with a dehumidifier can slow mould growth. And that may lessen year round symptoms of mould allergy.
- Career choice: Farming is not the only occupation that can expose you to higher levels of mould than usual. So can working in dairies, greenhouses, flour mills and bakeries, and wineries. Also repairing furniture.
- Your family: If someone closely related to you has an allergy, that puts you at greater risk of developing allergies too.
Diagnosing mould allergy symptoms
Only your GP can say for sure if you’re allergic to mould. Try keeping a record of what you think could be mould allergy symptoms. Here are some details to include:
- When do you experience symptoms, exactly?
- How long do your symptoms last?
- Do your mould allergy symptoms happen when you’re at home or outside?
- Are they worse at a particular time of the year?
- Are your symptoms worse at night?
- Do you know where you were when symptoms developed?
After taking your medical history your GP may recommend a skin prick or blood test to help make a diagnosis. Tests can’t tell you when or where you were exposed to mould, which is why an allergy diary could be useful.
Medicines for mould allergy symptoms
Antihistamines, corticosteroids and decongestants are usually the go-to treatments for mould allergy symptoms. All are available over the counter and come in either topical (nasal spray, eye drops) or oral (tablets, liquid) form.
Antihistamine blocks the chemical (histamine) that causes many of your mould allergy symptoms. Corticosteroids reduce inflammation by copying hormones made by your body. And decongestants reduce swelling in your nose to help you to breathe better.
These options may only give temporary relief. If you find they aren’t effective enough your GP may prescribe stronger allergy medicine. Talk to them first before giving a child symptom relieving medications.
Long-term treatment for mould allergy symptoms
Immunotherapy is a treatment that can provide long-term relief from some mould allergies. Tiny doses of your trigger, repeated regularly around three years, can change the way your immune system reacts. The goal is your mould allergy symptoms stop bothering you as much or at all.
