Can Mould Be Causing Your Allergy Symptoms?

A stuffy nose, sneezing and itchy eyes are often blamed on pollen or dust. But mould can also trigger allergy symptoms, both inside and outside your home.

Mould grows naturally in damp places. It releases tiny spores into the air, and people who are allergic to mould can develop symptoms when they breathe them in.

What Does a Mould Allergy Feel Like?

Mould allergy can cause many of the same symptoms as other environmental allergies.

Common symptoms include:

• Sneezing
• Runny nose
• Stuffy nose
• Itchy nose or throat
• Red, itchy or watery eyes
• Coughing

For people with asthma, mould exposure can also trigger symptoms such as wheezing, chest tightness or shortness of breath.

Where Does Mould Come From?

Mould needs moisture to grow.

Inside the home, it is more likely to develop in damp areas such as:

• Basements
• Bathrooms
• Around leaking windows
• Under sinks
• Around leaking pipes
• Areas affected by water damage

Outdoor mould is also common. It can grow on soil, plants, compost and fallen leaves.

This means mould allergy symptoms are not necessarily limited to one season.

Why Do Symptoms Sometimes Get Worse After Rain?

Wet weather creates good conditions for mould growth.

Outdoor mould can become more noticeable around damp soil, grass and fallen leaves. If you notice that your allergy symptoms seem worse after rainy or humid weather, mould could be one possible trigger.

That does not automatically mean you have a mould allergy. Pollen and other environmental allergens can cause very similar symptoms.

What Can You Do About Mould Indoors?

The most important step is controlling moisture.

If you have a leak, repair it rather than simply cleaning the visible mould. Otherwise, the mould may return.

A few practical steps can help:

### Keep Damp Areas Dry

Use bathroom and kitchen exhaust fans when needed. Make sure damp areas have good ventilation.

### Watch Your Basement

Basements can become humid, especially during the summer. A dehumidifier may help control moisture in damp spaces.

Remember to empty and clean the unit regularly.

### Fix Leaks Quickly

Check around sinks, windows, roofs and plumbing. Water problems should be repaired as soon as possible.

### Deal With Visible Mould

Small areas of mould on hard surfaces can often be cleaned and dried completely.

Larger mould problems or significant water damage may need professional assessment and cleanup.

Is Every Reaction to Mould an Allergy?

No.

Mould and damp environments can sometimes irritate the nose, throat and lungs even in people who do not have a true mould allergy.

This is one reason symptoms alone cannot always tell you exactly what is causing the problem.

How Do You Know If You Are Allergic to Mould?

Look for patterns.

Do your symptoms get worse in a damp basement? After working in the yard? Around wet leaves? In certain buildings?

Keeping track of where and when your symptoms happen can be useful.

An allergist can review your symptoms and medical history and decide whether allergy testing would be helpful.

When Should You See an Allergist?

Consider speaking with an allergist if:

• Your symptoms keep returning
• You have symptoms for long periods
• You cannot figure out what is triggering them
• Allergy medication is not giving you enough relief
• Your symptoms interfere with sleep or everyday activities
• You have asthma that seems worse in certain environments

Finding the actual trigger is important because mould, pollen, dust mites and pet allergies can look very similar.

The Bottom Line

Mould is everywhere, and most people are around it without having an allergic reaction. But for someone with a mould allergy, airborne spores can cause sneezing, congestion, itchy eyes and other respiratory symptoms.

Reducing moisture at home can help limit mould growth. If symptoms continue or you are unsure what is causing them, Dandelion Allergy Centre can help identify your triggers and develop a treatment plan that makes sense for you.

This article is for general information and does not replace medical advice from your healthcare provider.