An unusual case of anaphylaxisAnaphylaxis A severe allergic reaction that can turn fatal without treatment. Patients with SM are at a higher risk of developing 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 activationMast cell activation Describes when mast cells release histamine and other mediators into the blood stream in response to an allergen or other trigger. This leads to symptoms like fatigue, rash and, in severe cases, anaphylaxis. disorders was initiated. Baseline serum tryptaseTryptase A protein enzyme that is primarily produced by mast cells and stored in small pockets within the cells, known as granules. High levels of tryptase are a key indicator of SM. was elevated (16.9 ng/mL), suggesting persistent mast cell activation. Additional testing revealed sensitivity to various aeroallergens, and a bone marrow biopsyBone marrow biopsy A procedure to collect a sample of bone marrow using a needle. Often used to examine the characteristics of mast cells and diagnose SM. confirmed a clonal population of mast cells with a c-KIT mutation, consistent with indolent SMIndolent SM A subtype of nonadvanced SM caused by the abnormal accumulation of mast cells in the bone marrow and other organs. Indolent SM accounts for around 90% of SM cases..
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 cellMast cell A type of white blood cell produced in the bone marrow. They help defend against infections and play a key role in allergic reactions. In SM, mast cells become overactive and build up throughout the body. disorders, especially when traditional causes fail to fully explain the severity or recurrence of symptoms.
“This patient was diagnosed with indolent systemic mastocytosisMastocytosis Rare disease caused by the buildup of mast cells. Cutaneous mastocytosis primarily affects the skin and is more common in children, while systemic mastocytosis affects internal organs and is more common in adults. 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.
Sign up here to get the latest news, perspectives, and information about SM sent directly to your inbox. Registration is free and only takes a minute.
