Symptoms and Triggers of Mast Cell Activation

Mast Cell Activation and Triggers

Mast cells can be activated to release mediators by multiple triggers. Possible triggers of mediator release are shown below in Figure 1. Please note that any patient with a mast cell disease can potentially react to any trigger, and triggers can change over the course of the disease. In addition, patients may experience reactions to virtually any medications, including medications that they have tolerated previously. Common medication reactions in mast cell disease patients include, but are not limited to: opioids, antibiotics, NSAIDs, alcohol-containing medicines and intravenous vancomycin. Use with caution. More information related to drug hypersensitivity in mast cell diseases is available in a position paper by European specialists.¹

Figure 1. Some Potential Mast Cell Triggers^2-5

• Heat, cold or sudden temperature changes
• Stress: emotional, physical, including pain, or environmental (i.e., weather changes, pollution, pollen, pet dander, etc.)
• Exercise
• Fatigue
• Food or beverages, including alcohol
• Drugs (opioids, NSAIDs, antibiotics and some local anesthetics) and contrast dyes
• Natural odors, chemical odors, perfumes and scents
• Venoms (bee, wasp, mixed vespids, spiders, fire ants, jelly fish, snakes, biting insects, such as flies, mosquitos and fleas, etc.)
• Infections (viral, bacterial or fungal)
• Mechanical irritation, friction, vibration
• Sun/sunlight

Mast Cell Mediator Symptoms

The myriad symptoms patients with mast cell diseases experience during mast cell activation can wreak havoc on patients on a daily basis, and multiple organ systems, including pulmonary, cardiovascular, dermatologic, gastrointestinal, musculoskeletal, and neurologic can be involved. Table 1 lists some potential effects linked to specific mediators.^5-13 Symptoms (Table 2) may include, but are not limited to: flushing of the face, neck, and chest; headache; tachycardia and chest pain; abdominal pain, bloating, gastroesophageal reflux disease (GERD), diarrhea, vomiting; uterine cramps or bleeding; rashes, including maculopapular cutaneous mastocytosis (MPCM)/urticaria pigmentosa (UP), telangiectatic lesions; bone/muscle pain, osteosclerosis, osteopenia, osteoporosis; itching, +/- rash; blood pressure instability; brain fog, cognitive dysfunction; anxiety/depression; lightheadedness, syncope; and anaphylaxis. These symptoms may appear as acute (as in anaphylaxis, see Table 3) or as chronic conditions. It should be noted that the manifestation of anaphylaxis or similar symptoms among infants and preschoolers may be more difficult to identify.

Table 1. Possible Effects of Some Mast Cell Mediators^{13, 14}

This list is by no means complete and serves as an example. Mast cells secrete many mediators responsible for numerous symptoms within different organ systems.

Table 2. Mast Cell Mediator Symptoms^{12, 13}

Table 3. When Does this Become Anaphylaxis?

(Taken from the American Academy of Allergy, Asthma and Immunology (AAAAI) Anaphylaxis Emergency Action Plan¹⁵ and the Anaphylaxis Guidelines Pocketcard¹⁶)

Anaphylaxis is an acute life-threatening systemic reaction that results from the sudden, rapid, systemic release of mediators.

Only a few symptoms may be present. Severity of symptoms can change quickly. *Some symptoms can be life-threatening. ACT FAST! Use your anaphylaxis action plan! An AAAAI Anaphylaxis Card in English and Spanish is also available.