Pumpkin seed
Summary
Pumpkin (Cucurbita pepo) is a common fruit of an herbaceous creeper plant belonging to the family Cucurbitaceae. It is considered native to the USA (Eastern and Southwestern) and Northern Mexico. Cucurbita species are one of the most popular foods consumed worldwide and are used in several cuisines. The prevalence of pumpkin seed (C. pepo)-related food allergy is rare and is limited to a few case reports. However, oral ingestion of pumpkin seeds (either whole or in food preparations) can manifest symptoms ranging from oral allergy syndrome to respiratory symptoms and anaphylaxis. In pumpkin seed (C. maxima), Cuc ma 4 (50 kDa non reducing) and Cuc ma 5 (14 kDa) are identified as allergenic molecules. Additionally, another study has also reported the presence of a panallergen profilin (14 kDa) in the pumpkin seeds (C. pepo). Furthermore, pumpkin seeds are found to be cross-reactive with melon seeds, cashew nuts, and birch pollen.
Epidemiology
Worldwide distribution
Seed allergies have been reported to be increasing worldwide; however, the prevalence of pumpkin seed (C. pepo)-related food allergy is rare and is limited to a few case reports.
Route Of Exposure
Main
Ingestion of pumpkin seeds is considered the route of exposure. In addition, inhalation of pumpkin seed flour has also been reported to be responsible for pumpkin seed-related food allergy.
Clinical Relevance
Pumpkin seed allergy can manifest symptoms ranging from oral allergy syndrome to respiratory symptoms and anaphylaxis.
Oral allergy syndrome
A study confirmed oral allergy syndrome in a patient along with abdominal pain after consumption of pumpkin seeds (C. pepo) [based on in vitro testing, prick by prick (PP), and skin prick testing (SPT)].
Respiratory symptoms
Allergic symptoms (oropharyngeal swelling and itching, and bronchial asthma) were observed in 3 fishermen (29-49 years) after consuming food containing pumpkin seeds. The patients were found to exhibit hypersensitivity to pumpkin seeds (confirmed through PP, in vitro testing, and SPT)
Anaphylaxis
A study confirmed anaphylaxis (based on PP, skin prick testing SPT, and in vitro testing) in 2 patients after ingestion of pumpkin seeds (C. pepo).
Another study reported immediate allergic reactions with severe and systemic symptoms like anaphylaxis in 4 patients (12-32 years). All the patients exhibited a positive specific IgE and SPT towards pumpkin seeds (C. maxima) extract.
A case report concerning a 4-year-old girl with a history of asthma also revealed anaphylactic reactions after consuming pumpkin (C. maxima) seeds (confirmed through SPT). Additionally, anaphylaxis was also observed in a 70-year-old woman after consuming pumpkin (C. maxima) seeds confirmed through SPT.
Prevention And Therapy
Prevention strategies
Avoidance
Complete avoidance of pumpkin seeds and pumpkin-based food from the diet can be considered as preventive measures for pumpkin seed allergy.
Cross-Reactivity
Cuc ma 4 is cross-reactive with melon seeds and cashew nuts.
Another study reported cross-reactivity between the profilin present in pumpkin seeds (C. pepo) and birch.
References
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