D1.299 - Lychee-Induced Anaphylaxis: Data from the French Allergy-Vigilance Network since 2002

Lychee is an exotic fruit native to southern China, but its cultivation and consumption are now widespread worldwide. Lychee allergens remain poorly characterized, and cases of anaphylaxis are rarely reported in the literature.

We analysed lychee-induced anaphylaxis (Ring grades 2-4)  reported to the French Allergy Vigilance Network from 2002 to 2025. Demographic data, clinical manifestations, sources of lychee exposure, and results of the allergological work-up were analyzed. 

Between 2002 and 2025, 14 cases of lychee-induced anaphylaxis were reported. The median age was 14.5 years, with a female-to-male ratio of 2.25. Overall, 70% of patients experienced grade II anaphylaxis and 30% grade III. Hospital management was required in 71% of cases. For three patients, the reaction occurred upon first known exposure to lychee. Cofactors were identified in two cases (physical exercise and cold exposure in one case, nonsteroidal anti-inflammatory drugs in the other). Among patients, 8.3% had a history of asthma, 25% atopic dermatitis, and 71% pollen-induced allergic rhinoconjunctivitis (50% to weeds, 27% to grasses, and 10% to birch pollen). In addition, 46% had another food allergy (28% to mango and 21% to celery). Lychee-induced anaphylaxis was triggered by consumption of raw fruit in 92.8% of cases, and by lychee-flavored yogurt in one case. In 70% of cases, ingestion involved one lychee or less.

Lychee is a rare but emerging allergen capable of inducing severe anaphylaxis. In most cases, lychee allergy appears to be associated with pollen-related cross-reactivity, possibly mediated by defensins and profilins. Molecular investigations may help to better characterize the allergenic sensitization profiles of these patients.