Allergy to pumpkin and cross-reactivity to other Cucurbitaceae fruits

Abstract

Fruits belonging to the Cucurbitaceae family 1 have been reported to be one of the most important allergycausing fruits in the United States. To the best of our knowledge, although pumpkin is a member of the above family and allergy to roasted pumpkinseed has been described, we have not found any indexed report concerning allergy to this fruit. The aim of our study was to describe the clinical and immunologic findings in this first reported case of allergy to pumpkin. CASE REPORT The patient was a 28-year-old woman with a history of rhinoconjunctivitis and asthma who was allergic to pollens and cat dander. She was referred to our clinic after development of several episodes of itching of the mouth, angioedema of the lips and face, generalized itching, and mild dyspnea within 15 minutes after eating pumpkin soup or thin vermicelli (sweet made from the fibrous part of the pumpkin). The patient required treatment with inhaled bronchodilator, antihistamines, and methylprednisolone in the emergency unit. She had not consumed any other food, beverages, or drugs coinciding with these episodes. In vivo tests Skin prick tests to an aeroallergen commercial battery (pollens, mites, fungi, and cat and dog dander) according to European Academy of Allergology and Clinical Immunology (EAACI) guidelines were positive to cat dander and most of the tested pollens (grasses, trees, and weeds). The skin prick-by-prick test responses with fresh fruits were positive to pumpkin (10 × 9 pseudopoda) and also to other Cucurbitaceae fruits: cucumber (5 × 4 mm), zucchini (4 × 3 mm), muskmelon (7 × 6 mm), and watermelon (7 × 3 mm). The open oral challenge test response to fresh pumpkin, according to the previously described method, 2 was positive, and it was also positive for cucumber, muskmelon, and watermelon. In vitro assays The pulp of several Cucurbitaceae fruits was processed according to the method previously described. 2 The initial protein content of the extracts was enriched by a method based on ion-exchange chromatography.3 The protein concentration of all fruit allergenic extracts was adjusted to 1 mg/mL.