Mastocytosis Worsens Venom Allergy Outcomes

The first time I got stung by a wasp, my knee swelled up to nearly 4x its size. While my allergy is more frustrating than fatal, I know that I am not alone; there are numerous people out there who also have venom allergies, some severe. According to Medical XPress, Michigan Medicine researchers have now linked venom allergies to an increased risk of mastocytosis. More importantly, those with venom allergies and mastocytosis are also at a heightened risk of having severe and possibly fatal reactions than those without allergies. See the full research findings published in the Journal of Allergy and Clinical Immunology.

The Research

For many patients, mastocytosis first manifests following serious or life-threatening anaphylaxis caused by a bee or wasp sting. Thus, researchers wanted to understand how venom allergies and mastocytosis intersected.

During the research, allergists from Michigan Medicine explored data from 27 million U.S. patients. This data was sourced using an insurance database. By using such widespread data, researchers turned this study into one of the largest in the country in regards to Hymenoptera venom. According to UpToDate:

Systemic allergic reactions to the venom of insects in the order Hymenoptera (which includes bees, yellow jackets, wasps, and hornets) can be life-threatening.

Once digging through the research, the allergists determined that:

  • Approximately 0.1% of patients with venom allergies also had mastocytosis. While this might seem like a small number, this helps to put it into perspective: 0.1% of patients with mastocytosis is approximately 10x higher than people without venom allergies.
  • Patients in Europe have higher rates of mastocytosis and venom allergies than the United States. Researchers hypothesize that this could be due to venom sensitization.
  • Venom desensitization immunotherapy can help improve patient outcomes in those with severe allergies.
  • Tryptase is secreted by allergy cells. Analyzing patient tryptase levels allows researchers to predict who might have negative reactions to desensitization immunotherapy.


Gene mutations are responsible for most pediatric and adult mastocytosis diagnoses. When these genes mutate or malfunction, it allows for mast cell over-activation. Normally, mast cells – also called mastocytes or labrocytes – play a role in immune function. However, the overproduction of mast cells can have damaging health consequences. Thus, mastocytosis is a chronic condition characterized by excess mast cell accumulation throughout the body. As these cells build up, they can collect in the liver, spleen, skin, gastrointestinal tract, lymph nodes, or even bone marrow.

Altogether, there are multiple forms of mastocytosis. In the cutaneous form, the skin is affected. Patients experience:

  • Low blood pressure
  • Small, flat, brown lesions made clearer by scratching
    • Note: Blistering of these lesions is also a symptom of cutaneous mastocytosis.
  • Skin thickening or discoloration
  • Diarrhea
  • Severe anaphylaxis / anaphylactic shock
  • Pruritus (intense itching)
  • Gastrointestinal bleeding

Next, the indolent systemic form also affects or involves the skin in some way. Typically, these patients experience gastrointestinal symptoms, such as bleeding or diarrhea, as well as spleen and liver enlargement. Patients may also have mast cell leukemia, an aggressive blood cancer and rare, often fatal form of mastocytosis. Then there is systemic mastocytosis. Generally, this form affects adult patients. 1 in 3 patients have systemic mastocytosis. However, most patients do not develop skin lesions. Finally, the last form is aggressive systemic. In this form, patients typically experience loss of bone, bone marrow, and liver function.

Symptoms and Triggers

Additional related symptoms include:

  • Abdominal discomfort
  • Bone softening
  • Itching or flushing
  • Fatigue
  • Mood changes
  • Nausea and vomiting
  • Muscle and joint pain
  • Stomach ache
  • Heartburn
  • Spleen and liver enlargement

There are certain triggers which could trigger an attack of mastocytosis. These include:

  • Exercise or other rigorous physical activity
  • Physical or emotional stress
  • Alcohol or medication use
  • Sudden temperature changes
  • Skin friction or rubbing

Learn more about mastocytosis.

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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