Allergy and intolerance
IgE antilichamen Penicillium
Antibodies against the mold Penicillium; shows whether the immune system is sensitive to this mold, not whether it bothers you.
Everything about this testWhat it measures
Penicillium chrysogenum is a mold that mainly grows indoors, in damp places such as the bathroom, the basement or behind wallpaper, and on spoiled food. The mold is also found in compost, potting soil and hay. This test measures the amount of IgE antibodies against Penicillium chrysogenum in the blood, in kU/l. The body only makes these antibodies after it has previously been in contact with the allergen; this is called sensitization. Sensitivity to this mold says nothing about an allergy to the antibiotic penicillin: that is a different allergy, which is not measured with this test.
- Sensitization to the mold Penicillium: the body has made IgE antibodies against it
- Support in working out a suspected mold allergy, together with the history of the symptoms, especially with symptoms in a damp home
High
A value above the cut-off means that you have IgE antibodies against Penicillium: sensitization. That is not the same as an allergy. In people with nose or eye symptoms, coughing or shortness of breath in a home with damp and mold patches, or when working with compost, hay or potting soil, a positive result can fit an allergy to this mold. According to Thuisarts.nl, molds can cause nasal symptoms all year round. Antibodies against different molds often occur together, so the results for other molds can be positive as well. In people without such symptoms, a positive result only means that the antibodies are there; no treatment follows.
Low
A value below the cut-off means that no IgE antibodies against this allergen were found. An IgE-mediated allergy to this allergen is then much less likely, although it is not completely ruled out. Symptoms can also come from another allergen that was not tested, or have a non-allergic cause.
If your result is abnormal
The GP mainly looks at the history: when and where the symptoms occur, and whether there is asthma. With a positive result and matching symptoms, the advice is mainly about limiting contact with molds, for example by tackling damp and mold patches at home and ventilating well. If needed, medication for the nose, eyes or airways follows, and with symptoms that are not brought under control this way, a referral to an ENT specialist, lung specialist or allergist may follow.
Reliability
A positive IgE result shows sensitization, not allergy: it only says that there are antibodies, not that you get symptoms from them. The Dutch medical specialists' guideline (FMS) on upper airway allergy says this literally and recommends choosing a test for single allergens based on the history of the symptoms; for food allergy, the FMS guideline on food challenge testing calls the history of the symptoms the cornerstone of diagnosis and a food challenge in hospital the gold standard. The result therefore only means something if it fits when, where and after contact with what you get symptoms. A positive result without symptoms is not treated.
Limitations
- Sensitization without symptoms is common; the result can only be interpreted together with the history of the symptoms.
- Related allergens can recognize each other's antibodies (cross-reaction), for example pollen and nuts or fruit; a positive result then does not mean that this particular allergen causes the symptoms.
- The test measures all proteins from the allergen source together; testing for individual proteins (components) can say more in case of doubt.
- Laboratories use different measurement methods and cut-off values; results from different labs cannot be compared one to one.
How common is this
Molds are, alongside pollen, house dust mite and pets, a known cause of allergic nasal symptoms. Mold allergy is less common than allergy to pollen or house dust mite. Sensitization is more common than the allergy itself.
Who is this useful for
Useful with nose or eye symptoms, coughing or shortness of breath that are present all year round and are worse indoors, especially in a home with damp and mold patches, or when working with compost, hay or potting soil. Also with asthma where the symptoms get worse in such surroundings. In people without such symptoms, the test adds nothing: sensitization without symptoms is not a disease and is not treated.
Sources
- NVKC, allesovertesten.nl: Allergie (RAST)
- FMS Richtlijnendatabase: Allergie van de bovenste luchtwegen, module Aanvullende diagnostiek
- FMS Richtlijnendatabase: Voedselprovocatie, module Plaatsbepaling diagnostiek voedselallergie
- Thuisarts.nl: Ik heb allergie
- Thuisarts.nl: Ik heb lange tijd of vaak neusklachten door een allergie
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results