An unusual case of anaphylaxis following a meal with ackee fruit led to the unexpected diagnosis of indolent systemic mastocytosis (SM) in a 73-year-old woman, according to a recently published abstract in Annals of Allergy, Asthma & Immunology.
Ackee fruit is infamous for causing “Jamaican vomiting sickness” when unripe due to its high content of hypoglycin A, a toxin that disrupts mitochondrial metabolism and results in low blood sugar, vomiting and altered mental status.
These symptoms are not immune-mediated and differ significantly from allergic responses, such as urticaria and asthma. While most cases of ackee toxicity follow a toxic-metabolic pathway, a handful of allergic reactions have been reported, including anaphylaxis, suggesting that the fruit could act as an allergen in rare sensitized individuals.
In this case, the patient presented to the emergency department in circulatory collapse after consuming a dish where ackee had been boiled and sautéed with codfish, onions, peppers and garlic. Within 30 minutes of ingestion, she developed profuse diarrhea, shortness of breath, and subsequently vomited and aspirated, leading to unconsciousness.
On arrival, she exhibited hypotension and generalized urticaria, requiring vasopressor support and intubation.
After stabilization, she recovered within three days. When the same ingredients except ackee were reintroduced into her diet, no adverse reactions occurred.
Given the unusual severity of the episode and the exclusion of other causes, a work-up for mast cell activation disorders was initiated. Baseline serum tryptase was elevated (16.9 ng/mL), suggesting persistent mast cell activation. Additional testing revealed sensitivity to various aeroallergens, and a bone marrow biopsy confirmed a clonal population of mast cells with a c-KIT mutation, consistent with indolent SM.
Read more about SM testing and diagnosis
SM can initially present with a single anaphylactic episode, often triggered by foods, medications or insect stings. The case highlights the importance of distinguishing between food toxin reactions and allergic reactions. Anaphylaxis attributed to ackee fruit, though rare, should prompt clinicians to investigate underlying mast cell disorders, especially when traditional causes fail to fully explain the severity or recurrence of symptoms.
“This patient was diagnosed with indolent systemic mastocytosis after an initial presentation with anaphylaxis post-ingestion of an Ackee-containing dish; post-prandial illness in similar cases should not be disregarded as Jamaican vomiting illness without proper evaluation of symptoms,” the authors wrote.
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