Published online: June 9, 2020
Mastocytosis refers to a group of heterogenous disorders characterized by excessive activation and accumulation of mast cells in the skin and/or internal organs. Patients with mastocytosis have an increased risk for severe anaphylaxis, particularly to Hymenoptera venom. It is, therefore, hypothesized that food allergies may be more common or severe. This concern may lead to increased dietary elimination that could unnecessarily impair quality of life. However, this issue has never been systematically investigated.
A recent study by Jarkvist et al. published in The Journal of Allergy and Clinical Immunology: In Practice for the first time systematically investigated the actual prevalence and severity of food-related hypersensitivity reactions in these patients. The authors conducted a retrospective study among a large cohort of 204 consecutive adult patients, 170 patients with the diagnosis of mastocytosis and 34 with monoclonal mast cell activation syndrome. Self-reported food allergy as recorded as well as determination of true allergy by allergist evaluation and testing.
The authors found that 20.6% of the patients had symptoms related to food, which is a prevalence comparable to the general adult population. Interestingly, the frequency of true food allergy was rare, as only 3.4% of cases were confirmed by relevant history and IgE-sensitization. Additionally, the most common IgE-mediated adult food allergy in these patients was the Oral Allergy Syndrome. In general, most symptoms were mild and restricted to the skin (86%), with pruritus and flushing being the most common ones. The next most common symptoms affected the gastrointestinal system (45%). However, only five patients had severe anaphylaxis corresponding to an overall prevalence of 2.5%.
Regarding the most common incriminated food elicitors, the largest category were the plant-based foods including apple, kiwi, strawberry, plums, nuts and spices/spicy foods. The remaining categories of reported food-elicitors were alcohol, seafood, cheese and meat. The authors also searched for potential risk factors for predicting food hypersensitivity; nevertheless, there were no significant differences between the groups regarding age, gender, atopic status or IgE levels.
The current study has several conclusions, which are directly relevant to clinical practice. Firstly, although rare, severe anaphylaxis from foods in patients with mastocytosis does exist, but it is a much less frequent elicitor than insect venoms. Further, most reactions are mild, and the frequency of IgE-mediated reactions is low (3.4%). The Oral Allergy Syndrome appears to be the most common IgE-mediated adult food allergy in mastocytosis patients. Consequently, these findings suggest clinicians should be cautious in recommending any elimination diet in mastocytosis patients without obtaining a clear diagnosis of food hypersensitivity.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.