Low Frequency of IgE-Mediated Food Hypersensitivity in Mastocytosis

Background Patients with mastocytosis have an increased risk for severe anaphylaxis, particularly to hymenoptera venoms. These patients may also develop more often systemic hypersensitivity reactions to certain foods. However, this issue has not been systematically investigated. Objective We aimed to determine prevalence and severity of food-related hypersensitivity (FH) reactions among patients with clonal mast cell disorders (CMD). Methods A retrospective study was conducted among 204 (≥ 18 years) consecutive patients who presented with confirmed CMD (170 with mastocytosis and 34 with monoclonal mast cell activation syndrome [MMAS]). All patients underwent thorough allergy work-up where self-reported FH-reactions were evaluated. Results The prevalence of self-reported FH was 20.6%. The frequency of immunologically mediated reactions was uncommon, as only 3.4% were confirmed by relevant history and IgE-sensitization. Among patients with FH, five had severe anaphylaxis corresponding to an overall prevalence of 2.5%. Most symptoms were restricted to skin (86%), followed by gastrointestinal tract (45%); similar to symptoms that occur in mastocytosis patients also without food-intake. Nuts, spicy foods, seafood and alcohol were the most common incriminated elicitors. There was no significant difference between the groups regarding age, gender, atopic status or IgE levels. Conclusion Anaphylaxis from foods in mastocytosis does exist and is severe, although foods are less frequent elicitor than insect venoms. Further, the frequency of overall FH-reactions is comparable to the general population and most reactions are mild, non-allergic and unconfirmed. Consequently, our results do not support the elimination of any diet in CMD patients without history of FH.