Mushroom Allergies: Are They Rare Or Common?

Mushroom allergies are relatively rare, but they can be life-threatening. The overall extent of mushroom allergies is unknown, but it is estimated to be very slight (1%) from ingestion. However, it could be as prevalent as pollen and mould allergies, affecting 10-30% of an allergic population. Mushroom allergies occur when the immune system mistakenly identifies mushroom allergens, such as proteins, spores, and other components, as harmful substances. This misidentification leads to an allergic reaction, which can vary in severity and range from mild discomfort to anaphylaxis.

Mushroom allergy prevalence

Mushroom allergies are relatively rare, but they can be life-threatening. They are not as common as other food allergies, but they can still be a serious health concern for those affected. The overall extent of mushroom allergy is unknown. It may be very slight (1%) from consuming mushrooms, but it could also be as prevalent as pollen and mould allergies (10-30% of an allergic population).

Mushrooms are a versatile and widely consumed ingredient, enjoyed in various cuisines worldwide. However, they can trigger adverse reactions, including allergic responses ranging from mild to severe. Mushroom allergies occur when the immune system mistakenly identifies mushroom allergens (the proteins found in mushrooms) as harmful substances. This misidentification leads to an allergic reaction, which can manifest in various ways.

While anyone can develop a mushroom allergy regardless of age or background, certain factors may increase the likelihood. These include a family history of allergies, existing food allergies, or a predisposition to allergic conditions such as asthma, eczema, or mould allergy. This is due to the potential cross-reactivity between mushroom proteins and moulds.

Among the allergic population, reactions can vary significantly, especially when considering inhalation exposure to spores, which can lead to severe allergic reactions in susceptible individuals. Mushrooms contain various proteins, spores, and other components that can trigger allergic reactions. The most common allergenic proteins found in mushrooms are usually associated with the fungi’s reproductive spores, which can become airborne and cause respiratory symptoms in sensitive individuals.

Oral allergy syndrome (OAS) can occur in individuals with a sensitivity to both raw mushrooms and certain environmental allergens, leading to specific IgE responses. Common symptoms include itching, hives, swelling of the lips, face, or throat, and gastrointestinal distress such as nausea, vomiting, or diarrhoea. These symptoms may appear shortly after consuming mushrooms or inhaling mushroom spores. For some individuals, inhaling airborne mushroom spores can lead to a respiratory allergy, causing symptoms such as sneezing, coughing, wheezing, and shortness of breath.

Mushroom allergy symptoms

The overall extent of mushroom allergies is not known, but it may be very slight (1%) from eating. However, mushroom allergies can cause serious health concerns for those affected. Mushroom allergies occur when the immune system mistakenly identifies mushroom allergens, the proteins found in mushrooms, as harmful substances. This misidentification leads to an allergic reaction, which can manifest in various ways.

Mild symptoms of a mushroom allergy may include a rash, itching, hives, sneezing, nasal congestion, and minor digestive issues such as stomach discomfort. These symptoms are comparable to allergies from other sources like maple trees, aspen trees, and mugwort. Antihistamines can help alleviate these mild symptoms.

More severe symptoms can indicate an anaphylactic reaction, a life-threatening allergic response that requires immediate medical attention. These may include difficulty breathing, wheezing, dizziness, rapid heartbeat, severe abdominal pain, swelling of the throat, tongue, mouth, or lips, and a sudden drop in blood pressure. For severe symptoms, doctors may prescribe corticosteroids to reduce inflammation. In emergency cases, such as anaphylaxis, epinephrine (also known as adrenaline) is administered.

Mushroom allergy diagnosis

The overall extent of mushroom allergy is not known. It may be very slight (1%) from eating, but could be as prevalent as pollen and mould allergies (10-30% of an allergic population).

Symptoms

The allergic reaction is caused either by eating mushrooms or inhaling their spores. Different species of mushrooms can cause various signs and symptoms. Consumption of mushrooms can trigger skin irritation, hives, and rashes. Some people also reported swelling of the lips, mouth, and throat due to mushrooms. Other symptoms include coughing, wheezing, vomiting, and diarrhea.

Skin Tests

The most common method of diagnosing allergies is the skin prick test, also known as the puncture or scratch test. A small amount of the suspected allergen, in this case, mushroom extract, is pricked or scratched into the skin. If the skin develops a raised, red, itchy bump, it indicates that the person is allergic to mushrooms.

Blood Tests

Blood tests are another common method of diagnosing allergies. These tests measure the amount of specific antibodies, known as Immunoglobulin E (IgE), in the blood. If the IgE levels are high, it indicates an allergic reaction. However, results from blood tests are typically available after a few days, unlike the immediate results from skin prick tests.

Food Allergy Test

During this test, a minute amount of mushroom protein is injected into the skin. If any inflammation or redness is observed, the patient is tested positive for a mushroom allergy. Doctors should be prepared to treat any adverse reaction that could occur during the test.

Mushroom allergy treatment

The overall extent of mushroom allergies is unknown. It may be very slight (1%) from eating, but it could also be as prevalent as pollen and mould allergies, affecting 10-30% of an allergic population.

If you suspect that you have a mushroom allergy, consult an allergy doctor or allergist for diagnosis and treatment.

Diagnosis

The two most common methods of diagnosing allergies are through a skin prick test and a blood test. The skin prick test, also known as the puncture or scratch test, is the most common method of diagnosing allergies. In this test, a small amount of the suspected allergen, in this case, mushroom extract, is pricked or scratched into the skin. The blood test measures the amount of specific antibodies, known as Immunoglobulin E (IgE), in the blood. If the IgE levels are high, it indicates an allergic reaction.

Treatment Options

There is currently no cure for mushroom allergies, but there are several treatment options available. The choice of treatment depends on the severity of the allergy and the patient's overall health condition.

• Medications – Over-the-counter (OTC) antihistamines can help alleviate mild symptoms such as a runny nose, itching, sneezing, hives, and itching. Antihistamines do not treat anaphylaxis, a severe and life-threatening allergic reaction.
• Allergy shots – Also known as immunotherapy, this treatment option involves gradually exposing the immune system to small amounts of the allergen to build tolerance.
• Epinephrine – In cases of severe anaphylaxis, immediate treatment with epinephrine is required. Epinephrine is a medication that can rapidly reverse the symptoms of anaphylaxis.
• Home remedies – These include avoiding mushrooms, staying hydrated by drinking plenty of fluids, and using over-the-counter hydrocortisone cream for skin reactions.

Mushroom allergy prevention

The exact prevalence of mushroom allergies is unknown. However, it is estimated to be very slight (1%) when caused by eating mushrooms, but it could be as common as pollen and mould allergies (10-30%) when inhaled.

Avoid Mushroom Consumption and Exposure

If you are allergic to mushrooms, it is crucial to avoid consuming them. Mushrooms can cause allergic reactions when ingested, inhaled, or even through skin contact. Avoid handling mushrooms directly and ensure that they are not present in any food you consume.

Be Cautious with Packaged and Fermented Foods

Some packaged foods, such as sour cream, dried fruits, alcohol (beer and wine), sour milk, cheese, and pickled meat or fish, may contain traces of mushrooms or mould that can trigger an allergic reaction. Therefore, it is important to read labels carefully and consume these products in moderation or avoid them altogether if necessary.

Prevent Mould and Fungi Growth

Mushrooms belong to the fungi family, and people with mushroom allergies may also be sensitive to other types of fungi and mould. To prevent mould and fungi growth, ensure that your home is well-ventilated and free from damp areas. This will help reduce the risk of exposure to mould spores that may trigger allergic reactions.

Carry Anti-Allergic Medications

It is always a good idea to carry anti-allergic medications with you, especially if you have a history of severe allergic reactions. Over-the-counter antihistamines can help alleviate mild symptoms such as itching, rashes, and sneezing. For more severe symptoms, such as anaphylaxis, it is crucial to seek immediate medical attention.

Understand Cross-Reactivity with Other Antigens

Mushroom allergies may be linked to allergies to other airborne fungi and antigens. For example, approximately 70% of reported adverse reactions to Quorn, a mycoprotein-based meat alternative, occur due to cross-allergenicity with another antigen. Understanding potential cross-reactivities can help you identify and avoid other allergens that may trigger similar allergic reactions.

Remember, if you suspect you have a mushroom allergy, it is important to consult a physician for a proper diagnosis and assessment of your symptoms. They may recommend allergy tests, such as skin prick tests or blood tests, to confirm the presence of a mushroom allergy.

Frequently asked questions