Mastocytosis and insect venom allergy

Area of Science:

• Allergy and Immunology
• Clinical Medicine

Background:

• Mastocytosis is a condition associated with an increased risk of severe anaphylaxis.
• Elevated baseline serum tryptase is a significant risk factor for severe hymenoptera sting reactions.

Purpose of the Study:

• To analyze the link between systemic allergic hymenoptera sting reactions and mastocytosis.
• To discuss the diagnosis and treatment of patients with both conditions.

Main Methods:

• Review of recent large studies on mastocytosis patients and hymenoptera sting reactions.
• Analysis of the association between elevated baseline tryptase and severe anaphylaxis.

Main Results:

• Patients with mastocytosis experience a higher incidence of severe anaphylaxis after hymenoptera stings.
• Elevated baseline tryptase strongly correlates with severe anaphylaxis in hymenoptera venom allergy.
• Fatal sting reactions have been reported in mastocytosis patients, particularly after discontinuing venom immunotherapy.
• Venom immunotherapy provides protection against further sting reactions in most mastocytosis patients.
• Allergic side-effects during immunotherapy are more common in mastocytosis patients, especially with Vespula venom allergy.

Conclusions:

• Baseline serum tryptase should be measured in all patients with anaphylaxis after hymenoptera stings.
• A tryptase level above 11.4 microg/l suggests mastocytosis and a high risk of severe anaphylaxis.
• Venom immunotherapy is a safe and effective long-term treatment for mastocytosis patients with venom allergy.