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Allergy testing

Mould allergy testing

Testing for allergy to indoor and outdoor moulds - a frequently missed trigger of asthma and autumn rhinitis.

Key facts

At a glance

  • The pattern: symptoms in damp weather, autumn, or damp buildings - and mould allergy is a recognised driver of difficult asthma.

  • Testing: skin prick or specific IgE blood tests against common moulds such as Alternaria, Cladosporium and Aspergillus.

  • Results: skin tests read in 20 minutes; blood results typically within one to two weeks privately.

  • Special case: Aspergillus testing matters in asthma, where sensitisation can indicate the treatable condition ABPA.

  • Follow-up: an allergist or respiratory specialist links results to your home environment and asthma control plan.

The full picture

What this test involves, and how to get it

Mould allergy is easy to miss because its calendar is vaguer than pollen: outdoor moulds such as Alternaria and Cladosporium peak in late summer and autumn, while indoor moulds in damp housing cause symptoms year-round. Sensitisation is confirmed with skin prick or specific IgE blood testing against a panel of common species. The stakes are higher than ordinary rhinitis - Alternaria sensitisation is associated with more severe asthma, and Aspergillus deserves particular attention in asthmatics, where it can signal allergic bronchopulmonary aspergillosis (ABPA), a distinct, treatable condition requiring further blood tests and imaging.

Testing is worthwhile when symptoms track dampness or autumn, when asthma is hard to control, or when a damp home raises the question of cause and effect. Results guide practical steps - ventilation, dehumidification, remediating visible mould, and appropriately escalated asthma treatment - and provide objective evidence sometimes needed in housing disputes. NHS testing runs through allergy or respiratory clinics after GP referral; private allergy clinics can complete skin or blood testing within days, with respiratory review available quickly where Aspergillus-related disease needs excluding.

A quiet reminder

This guide is for information, not medical advice.

Your own clinician knows your history and can tell you which parts apply to you. Next review of this page: 2027-09-27.

Frequently asked

Common questions about Mould allergy testing.

Quick, plain-English answers to what people ask us most.

  • What does mould allergy testing check?

    It looks for an allergic (IgE-mediated) response to common mould and fungal spores, usually via a skin prick test or a blood test measuring specific antibodies to different mould species.

  • Why would a doctor order mould allergy testing?

    It's typically requested if you have ongoing symptoms like sneezing, congestion, coughing, itchy eyes, or worsening asthma that seem linked to damp environments, certain seasons, or specific buildings, and other causes have been considered.

  • Do I need to prepare for the test?

    For skin prick testing, your doctor may ask you to stop antihistamines for several days beforehand, as they can suppress the test's reaction and lead to a false negative result. Blood tests don't usually require stopping antihistamines.

  • What happens during the test?

    Skin prick testing involves small amounts of allergen extracts placed on your skin, lightly pricked, with results read after about 15 to 20 minutes. Blood testing is a standard blood draw sent for specific antibody analysis.

  • Does it hurt or carry risks?

    Skin prick testing causes minor, temporary itching or a small bump where tested, similar to a mild insect bite, and is generally very safe. Blood testing involves only the usual brief pinch of a needle.

  • How long do results take?

    Skin prick test results are available the same day. Blood test results typically take a few days to a week.

  • What do abnormal results mean, and what happens next?

    A positive result confirms sensitisation to a specific mould type, which, combined with your symptom pattern, helps guide practical steps like improving ventilation, reducing damp, or considering treatments such as antihistamines. Sometimes a positive test doesn't perfectly match your actual symptoms, so your doctor will interpret it alongside your history rather than treating it as a standalone diagnosis. If mould exposure at home or work seems likely, addressing the source is often just as important as any test result.

  • Is this test available on the NHS, and how much does private testing cost?

    Mould allergy testing is available on the NHS, typically via a GP or allergy specialist referral, though waiting times for allergy clinics can vary. Private testing is typically available within days. Cost varies by provider.

  • Is mould allergy testing accurate and reliable?

    Both skin prick and blood allergy tests are well-validated methods, though a positive result shows sensitisation rather than guaranteeing clinical symptoms will occur on every exposure, so results are always interpreted alongside your history.

  • How do I book this test privately, and how quickly can I be seen?

    You can book privately online, often with appointments within a week, and have an allergy specialist or doctor discuss your results and practical management steps with you.