D1.25 - Cannabis-Fruit-Veggie Syndrome: From Respiratory Symptoms to Life-Threatening Anaphylaxis

The clinical relevance of Cannabis sativa allergy is rising globally due to increasing consumption. Clinical manifestations vary in severity from respiratory symptoms to severe systemic reactions following the ingestion of certain fruits or vegetables via cross-reactivity mechanisms. The diagnostic process is often complicated by concomitant sensitization to other aeroallergens and legal considerations.

A 24-year-old male presented for an allergy consultation reporting a two-year history of persistent rhinoconjunctivitis, worsening during summer, which responded to antihistamines. He subsequently admitted to frequent cannabis use associated with respiratory symptoms (cough, wheezing, dyspnea, sneezing, rhinorrhea). He also reported episodes of non-severe angioedema after consuming hummus and peach, and one episode of anaphylaxis (angioedema, pruritus, dyspnea, fatigue) after eating mandarins and apples, requiring emergency medical intervention. Evaluation included spirometry, ALEX2 multiplex test, respiratory allergen panels, and citrus-specific IgE. The patient is a chronic smoker (12 pack-years) and is treated with Levetiracetam for epilepsy.

Citrus-specific IgE was positive. The respiratory panel identified sensitization to tree, grass, and weed pollens. The ALEX2 test revealed primary sensitization to Can s 3 (Cannabis) at 5.41 kU/L, alongside a robust nsLTP sensitization profile: Pru p 3 (10.52 kU/L), Cor a 8 (7.99 kU/L), Ara h 9 (7.47 kU/L), Zea m 14 (7.72 kU/L), Jug r 3 (7.07 kU/L), Mal d 3 (7.01 kU/L), Api g 2 (3.70 kU/L), Pla a 3 (2.49 kU/L), Vit v 1 (2.10 kU/L), and Act d 10 (0.83 kU/L). PR-10 sensitizations were also noted (Fra a 1: 14.18 kU/L, Cor a 1: 6.66 kU/L, Mal d 1: 4.26 kU/L, and Fag s 1: 3.47 kU/L); however, apart from the specific triggers mentioned, the others were clinically tolerated both raw and cooked. Spirometry confirmed a reversible obstructive pattern (FEV1 increase of 240 mL). Serum tryptase was within normal limits. Following the initiation of therapy, strict cannabis cessation, and dietary eviction of high-load LTP foods, the patient’s evolution was favorable. An adrenaline autoinjector was prescribed.

This case identifies cannabis as a primary sensitizer for the nsLTP family, capable of triggering severe systemic reactions. Molecular diagnosis and detailed anamnesis were essential for establishing the diagnosis, risk stratification, and therapeutic management, particularly for a patient with comorbidities where systemic safety is a priority.