Allergy to Alternaria mould

What is Alternaria mould allergy?

Alternaria alternata is a mould that grows on grass, cereals and leaves and in soil. The spores are large and are spread by the wind, especially on warm, dry days in late summer. The most important allergen is called Alt a 1. Allergy to Alternaria is linked to asthma and can cause severe asthma symptoms in some people.

Symptoms

• A runny or blocked nose
• Sneezing and itchy eyes
• Coughing, wheezing and asthma

When are levels highest?

Outdoors, spore levels are highest from July to September, especially at harvest time when cereals are threshed. Alternaria can also grow indoors on damp surfaces, for example around windows.

Cross-reactivity

Alternaria has proteins that resemble those in other moulds, such as Cladosporium. People who react to one of them sometimes also react to the other.

How to get tested

Alternaria alternata (allergen code m6) is included in our Mould allergy and Mould allergy Plus tests. The test shows whether you have IgE antibodies to Alternaria.

Frequently asked questions

Why does my asthma get worse during thunderstorms?

During thunderstorms, pollen and mould spores can be broken into smaller particles that reach further down into the airways. Both grass pollen and Alternaria have been linked to such asthma attacks. If your asthma gets much worse, contact your doctor.

Is Alternaria dangerous?

For most people the spores are harmless. In people who are allergic they can cause symptoms, and if you have asthma it is important to have good treatment during the season.