Type:
Whole Allergen
Allergen Encyclopedia
Table of Contents
Whole Allergen
f87 Melon
f87 Melon Scientific Information
Display Name:
Melon
Route of Exposure:
Ingestion
Family:
Cucurbitaceae
Species:
melo
Latin Name:
Cucumis melo spp.
Other Names:
Common varieties: honeydew, cantaloupe, muskmelon
Summary
Melon (Cucumis melo) is a fruit grown worldwide and is part of the Cucurbitaceae family. There are many different cultivars, which vary in appearance, flavor and uses. Peel and flesh of the fruit are the sources of hypersensitivity and allergic reactions; one melon allergen (Cuc m 2), a profilin, is considered a pan-allergen due to its common presence in the plant world.
Pollen-food allergy syndrome (PFAS) and one of its common presentations, oral allergy syndrome (OAS) are the main clinical presentations of melon allergy. Symptoms tend to remain limited to the oral cavity; however more severe systemic reactions have also been described. Cross reactivity with a number of other plant food and pollen allergens usually occurs.
Allergen
Nature
Melon (Cucumis melo) is a fruit of the Cucurbitaceae family, related to cucumber and gourds such as pumpkin, squash, zucchini and watermelon (1, 2). Melons are grown worldwide in a variety of climates (3); different cultivars exist, with variable phenotypes with regards to shape and size of the fruit, texture and appearance of the peel, color and flavor of the flesh. The melon plant is a prostrate vine, with hairy branches, tendrils and heart-shaped leaves. The flowers are small and bright yellow (4).
Certain types of melon might be used when immature as fresh ingredient in salads, cooked or pickled; the mature fruits, rich in water and carbohydrates, are usually eaten fresh though preservation in the form of dehydration, juicing, canning or turning into jam are also possible. Melon seeds may also be eaten after roasting, and are a source of oil suitable for industry applications (5, 6).
Taxonomy
Taxonomic tree of melon, Cucumis melo (3) |
|
Domain |
Eukaryota |
Kingdom |
Plantae |
Phylum |
Spermatophyta |
Subphylum |
Angospermae |
Class |
Dicotyledonae |
Order |
Violales |
Family |
Cucurbitaceae |
Genus |
Cucumis |
Tissue
Flesh and peel of the fruit (7, 8).
Epidemiology
Worldwide distribution
Symptoms of allergic disease to melon have been studied in different countries, including Spain (9, 10), Korea (11), USA (12) and several Southern European countries (13). Profilin (a major melon allergen) sensitization is present in 15–50% of patients with pollen-food syndrome from different European and American areas (12).
Risk factors
Pollen allergies (due to the pan-allergen profilin) represent a risk factor for melon allergy (8, 11, 13, 14). Profilin sensitization alone is considered a risk factor for asthma, and of increased severity of allergic disease when in association with other allergens (12). Southern European ethnicity may be a risk factor (14).
Environmental Characteristics
Worldwide distribution
Melons are grown worldwide (3), with Asian countries the largest producers (15).
Route of Exposure
Main
Ingestion (8, 16, 17).
Secondary
Skin contact (17).
Clinical Relevance
Various studies have shown that patients with melon allergy were also sensitized to other foods (Cucurbitaceae, avocado, banana, chestnut, tomato, pineapple, peach, papaya, fig and kiwi), or had symptoms of pollen allergy, asthma, seasonal rhinitis and/or latex sensitization (10-13). Systemic allergic reactions to melon alone are considered rare (10, 17).
Atopic Dermatitis
Melon peel can cause contact allergy with symptoms of angioedema and urticaria (7).
Other diseases
OAS, consisting of IgE-mediated allergy symptoms limited to the oral cavity (Kim 2018), is a common presentation of sensitization to melon (8, 16, 17). Symptoms may present as tongue and pharyngeal pruritus, tongue angioedema, generalized oral pruritus, lip angioedema and facial erythema (18). In a study of 161 patients, of which 66 had confirmed melon allergy, 100% had oral symptoms, 19.7% had extra-oral symptoms and none had generalized urticaria or anaphylaxis (8). Other observed symptoms of melon allergy included facial angioedema, rhinoconjunctivitis and wheezing; additionally, severe systemic reactions suggestive of anaphylaxis were recollected when taking patient history (oropharyngeal symptoms, generalized urticaria and angioedema, nausea/vomiting, hypotension and wheezing) (10).
PFAS is a wider term that spans OAS and systemic symptoms, arising from exposure to certain foods that share allergens with plant pollens (11, 13). A study of 648 patients with symptomatic pollen allergies (allergic rhinitis, allergic conjunctivitis and/or bronchial asthma), showed that 41.7% of them had PFAS. Melon hypersensitivity caused 11.5% of PFAS cases. The symptoms following exposure to the allergenic foods (including melon) varied from anaphylactic reactions (8.9%), respiratory symptoms (20%), cutaneous symptoms (43%) and cardiovascular or neurological symptoms (less than 5%) (11). In another study, 815 patients with seasonal allergic rhinitis were examined; 20.5% reported PFAS symptoms, of which melon caused 15.6% (13).
Diagnostics Sensitization
Testing for food allergies involves measuring serum specific IgE responses, skin prick tests (SPTs) and oral challenges (7, 13).
In a study of 53 patients with a history of adverse reactions to melon ingestion, 68% had positive SPTs and 43% showed positivity for specific IgE; the overall clinical reactivity to food challenges was 36%. Significant differences may arise between results of SPTs, oral challenges and in vitro tests; therefore it is recommended that oral challenges should be included in latex-fruit allergy diagnostics (10).
Prevention and Therapy
Allergen immunotherapy
A 34-year old patient with pollen allergies and OAS following ingestion of fennel, cucumber and melon was able to tolerate fresh melon at oral challenge after 43 months of injectable immunotherapy containing grass pollen extracts (16).
Prevention strategies
Avoidance consists of eliminating melon (and other foods causing similar symptoms) from the diet, once accurately diagnosed (10). If a patient is allergic to the peel of a Cucurbitaceae, it is recommended that they avoid touching and eating the peel of other plants of the same Family (7).
Molecular Aspects
Allergenic molecules
Nonspecific lipid transfer protein (nsLTP) in the peel can be a cause of skin contact allergy (7).
Melon allergens have been identified in the flesh of the fruit; cucumisin, a thermostable protease (Cuc m 1); profilin, a ubiquitous pan-allergen (Cuc m 2); a protein of the PR-1 family, also a minor allergen (Cuc m 3); a malate dehydrogenase and a lectin (Lec 17-1) (7, 17, 19). Profilin is considered the major allergenic component of certain foods such as melon, being recognized by IgE in 71% of patients’ serum samples. An allergen with similar molecular weight (13kDa) was also identified as profilin in zucchini, cucumber and watermelon extracts. All were recognized by the IgE of patients with confirmed melon allergy (9). Allergy to melon, watermelon, citrus fruit, banana, peach and tomato was reported as marker of hypersensitivity to profilin in patients with OAS (12, 18). During in vitro studies of the characteristics of melon allergens, human saliva did not affect their reactivity, whereas most melon proteins (including profilin) lost IgE reactivity once exposed to simulated gastric fluid (9).
Table adapted from Allergome.org (20).
Allergen |
Type |
Mass (kDa) |
Cuc m 1 |
Serine protease; cucumisin |
79 |
Cuc m 2 |
Profilin; actin-binding protein |
14 |
Cuc m 3 |
PR protein |
2.5 |
Cuc m Lec17 |
Lectin |
17 |
Cuc m MDH |
Malate dehydrogenase |
36 |
Cuc m LTP |
Lipid transfer protein |
8 |
Cross-reactivity
Cross-reactivity has been shown with allergens from other plants. Nonspecific lipid transfer protein (nsLTP) from melon peel is cross reactive with nsLTPs from the peel of other Cucurbitaceae, as shown by binding of IgE from the serum of two patients with confirmed melon allergy (7). Other putative allergens were identified by sequence alignment and structural analysis using Cuc m 1, Cuc m 2 and Cuc m 3 sequences to mine the genome of other Cucurbitaceae (19). Latex is another plant-derived substance that is known to cross-react with plant foods, most likely due to the high sequence similarity of its profilin to other sources (12). Examples of allergenic profilins from other plants include Art v 4 (mugwort pollen), Bet v 2 (birch pollen), Phl p 12 (timothy grass), Ole e 2 (olive pollen), Cit s 2 (oranges) and Mus a 1 from bananas (14).
Compiled By
Author: RubyDuke Communications
Reviewer: Dr.Christian Fischer
Last reviewed: June 2022
References
- CABI. Cucurbitaceae (cucurbits) 2019 [cited 2022 06.01.22]. Available from: https://www.cabi.org/isc/datasheet/746.
- Guo J, Xu W, Hu Y, Huang J, Zhao Y, Zhang L, et al. Phylotranscriptomics in Cucurbitaceae Reveal Multiple Whole-Genome Duplications and Key Morphological and Molecular Innovations. Molecular Plant. 2020;13(8):1117-33.
- CABI. Cucumis melo (melon) 2021 [cited 2022 06.01.21]. Available from: https://www.cabi.org/isc/datasheet/16966.
- Schaffer AA, Paris HS. Melons, Squashes, and Gourds. Reference Module in Food Science: Elsevier; 2016.
- McCreight JD, Nerson H, Grumet R. 20 - Melon: Cucumis melo L. In: Kalloo G, Bergh BO, editors. Genetic Improvement of Vegetable Crops. Amsterdam: Pergamon; 1993. p. 267-94.
- Rezig L, Chouaibi M, Msaada K, Hamdi S. Chapter 54 - Cold pressed Cucumis melo L. seed oil. In: Ramadan MF, editor. Cold Pressed Oils: Academic Press; 2020. p. 611-23.
- Gandolfo-Cano M, González-de-Olano D, González-Mancebo E, Mohedano-Vicente E, Pastor-Vargas C, Bartolomé-Zavala B. Cross-reactivity Between nsLTPs From Cucurbitaceae Peels. Journal of investigational allergology & clinical immunology. 2018;28 1:65-6.
- Figueredo E, Cuesta-Herranz J, De-Miguel J, Lázaro M, Sastre J, Quirce S, et al. Clinical characteristics of melon (Cucumis melo) allergy. Ann Allergy Asthma Immunol. 2003;91(3):303-8.
- Rodriguez-Perez R, Crespo JF, Rodríguez J, Salcedo G. Profilin is a relevant melon allergen susceptible to pepsin digestion in patients with oral allergy syndrome. J Allergy Clin Immunol. 2003;111(3):634-9.
- Rodriguez J, Crespo JF, Burks W, Rivas-Plata C, Fernandez-Anaya S, Vives R, et al. Randomized, double-blind, crossover challenge study in 53 subjects reporting adverse reactions to melon (Cucumis melo). J Allergy Clin Immunol. 2000;106(5):968-72.
- Kim MA, Kim DK, Yang HJ, Yoo Y, Ahn Y, Park HS, et al. Pollen-Food Allergy Syndrome in Korean Pollinosis Patients: A Nationwide Survey. Allergy Asthma Immunol Res. 2018;10(6):648-61.
- Rodríguez Del Río P, Díaz-Perales A, Sánchez-García S, Escudero C, Ibáñez MD, Méndez-Brea P, et al. Profilin, a Change in the Paradigm. J Investig Allergol Clin Immunol. 2018;28(1):1-12.
- Lipp T, Acar Şahin A, Aggelidis X, Arasi S, Barbalace A, Bourgoin A, et al. Heterogeneity of pollen food allergy syndrome in seven Southern European countries: The @IT.2020 multicenter study. Allergy. 2021;76(10):3041-52.
- Matricardi PM, Kleine-Tebbe J, Hoffmann HJ, Valenta R, Hilger C, Hofmaier S, et al. EAACI Molecular Allergology User's Guide. Pediatr Allergy Immunol. 2016;27 Suppl 23:1-250.
- Carvalho AP, Moreira MM, Delerue-Matos C, Gomes AM, Freitas AC, Grosso C. Chapter 4 - Valorization of lipid by-products. In: Galanakis CM, editor. Lipids and Edible Oils: Academic Press; 2020. p. 133-74.
- Asero R. Fennel, cucumber, and melon allergy successfully treated with pollen-specific injection immunotherapy. Annals of Allergy, Asthma & Immunology. 2000;84(4):460-2.
- González-Mancebo E, López-Torrejón G, González de Olano D, Santos S, Gandolfo-Cano M, Meléndez A, et al. Identification of potential allergens involved in systemic reactions to melon and watermelon. Ann Allergy Asthma Immunol. 2010;104(3):271-2.
- Somoza ML, Prieto-Moreno Pfeifer A, Martín-Pedraza L, Victorio Puche L, Esteban Rodríguez A, Blanca-López N, et al. Skin Testing With Peach Peel Extract Versus Serum IgE to Pru p 3 as a Stronger Predictor of Peach-Induced Anaphylaxis. Allergy Asthma Immunol Res. 2021;13(6):922-32.
- Neeharika D, Sunkar S. Computational approach for the identification of putative allergens from Cucurbitaceae family members. J Food Sci Technol. 2021;58(1):267-80.
- Allergome. Cucumis melo. 2022.
