Patients with mastocytosis, which includes systemic mastocytosis (SM), faced an elevated risk of anaphylaxis, particularly from insect venom, while other allergies were less common or overreported, according to a study published recently in The Journal of Allergy and Clinical Immunology: In Practice.
The results confirmed that patients with mastocytosis in the U.S. are at a higher risk of venom-triggered anaphylaxis but have risks comparable to those of the general population for most medications.
What is SM?
Systemic mastocytosis (SM) is a rare hematological disease characterized by mast cells that are overactive and accumulate in different parts of the body such as the bone marrow, liver, spleen, gastrointestinal tract and lymph nodes.
Preemptive allergy avoidance is common, underscoring the need for patient education to prevent unnecessary restrictions. By understanding the patterns, health care providers could better manage allergies and improve the quality of care for individuals with mastocytosis.
Read more about SM signs and symptoms
“The advantage of our analysis is that it is a single center study in a mastocytosis referral center with rather uniform assessment and management, reducing the potential reporting variabilities as may occur in a multi-center study,” study authors said.
They added: “Our study also included many different subsets of patients including, pediatric and adult-onset patients. It also sheds light to the demographics of mastocytosis in a multiethnic U.S. population with the finding of increased prevalence in non-Hispanic white patients.”
This study involved 259 patients with confirmed SM or cutaneous mastocytosis and sought to clarify allergy prevalence and triggers. Drug and food allergies were frequently reported, but most were due to preemptive avoidance rather than confirmed reactions. Notably, 28% of participants experienced anaphylaxis , with Hymenoptera venoms, drugs and food being the most common triggers.
Demographic analysis revealed that mastocytosis was more prevalent among non-Hispanic white individuals (88%), significantly higher than the general U.S. population’s proportion of 57.8%.
SM predominated in adults (94.4%), while cutaneous mastocytosis was more common in children (83%). Among allergic conditions, 26% of participants had allergic rhinitis; 15.5% had asthma, and 8.5% had atopic dermatitis. Only asthma was significantly more common in patients with mastocytosis, particularly among adults, compared to the general U.S. population.
Self-reported drug allergies were the most common, with 74.9% of patients citing concerns. NSAIDs accounted for 28%, and penicillin accounted for 25% of the reports. Only 7.3% of participants experienced confirmed drug-induced anaphylaxis. Some 19.6% of patients reported food allergies, predominantly involving nuts, seafood, eggs and vegetables. Only 4% experienced food-induced anaphylaxis. The data highlighted the discrepancy between patient-reported allergies and verified allergic reactions.
Venom allergies, particularly to Hymenoptera stings, were confirmed in 10.4% of patients, with 84% of venom-triggered anaphylaxis occurring in adults. Radiologic contrast allergies were noted in 5%, with anaphylaxis confirmed in 1.9%, a rate higher than that in the general population. Vaccine allergies were rare, and COVID-19 vaccines were generally well tolerated.
