Melon is a food which may result in allergy symptoms in sensitised individuals.

Melon Allergy Test: Allergen Exposure

Melons have been cultivated by humans for thousands of years. Thought to originate in Asia, melons are members of the gourd family which grow on trailing vines. They are grown primarily for their fruit, which generally has a sweet, aromatic flavour.

There are a variety of cultivars, which vary in size, shape and colour. Examples include honeydew melon, muskmelon, winter melon, and various ‘netted’ cultivars known as cantaloupe.

The melon fruit is produced by an annual climbing or trailing herb with a fibrous root and grey-green, angular stems that have stiff, bristly, spreading hairs, mainly on the ridges. The fruit is ellipsoid in shape and is attached by a stout stalk.

Melons are generally a dessert fruit, eaten raw in slices or cubes, or as an ingredient in cold desserts such as sorbet. Their delicate flavour and high water content make them poor candidates for cooking and preserving. Their availability tends to be seasonal, but more-sophisticated transport is changing this in many locales.

The fruit can be used as a light, cooling cleanser or moisturiser for the skin, and is used in a variety of homeopathic remedies, including as a first-aid treatment for burns and abrasions.

Melon Allergy Test: Allergen Description

Various allergens present in melon have been characterised. Several IgE-binding proteins have been detected in melon extract with the most reactive one being a profilin.

A lipid transfer protein (LTP) has also been detected. It is highly resistant to pepsin digestion and is heat-stable, making it a potentially potent allergen.

Melon Allergy Test: Potential Cross-Reactivity

Extensive cross-reactivity between the different individual species of the Cucurbitaceae (gourd) family could be expected. The family includes melon, watermelon, squashes and pumpkin. Cross-reactivity has been demonstrated in vitro: 13 kDa proteins of zucchini, cucumber, and watermelon extracts were strongly recognised by the IgE antibodies of patients with melon allergy. These proteins were identified as profilins.

Amino acid sequence analysis of melon profilin alongside other profilins showed the most identity with watermelon profilin, and substantial cross-reactivity with profilin from tomato, peach and grape, and with profilin from the pollen of Bermuda grass.

Hypersensitivity to the birch tree profilin Bet v 2 has been strongly associated with clinical allergy to melon and watermelon.

A history of allergy to gourd fruits, citrus fruits, tomato, banana – or a combination of these – is a sensitive means to detect profilin-hypersensitivity, predictive in 85% of patients.

Melon Allergy Test: Clinical Experience

Melon may commonly induce symptoms of food allergy in sensitised individuals, in particular, in latex-allergic individuals.

Melon has been reported to be a frequent allergy-eliciting fruit in some areas in the United States, and the second-most-frequent allergy-eliciting fruit in Spain, where fruit allergy is the most important food allergy in adult patients.

The allergic reactions are usually immediate. Oral allergy syndrome is the most common manifestation of allergy to melon, but urticaria, and gastrointestinal symptoms, including nausea, vomiting and diarrhoea, have been reported.

Dermatitis, angioedema and anaphylaxis are possible. Melon allergy is commonly associated with oral allergy syndrome (OAS) and with hypersensitivity to pollens and other plant foods.

The most common clinical feature of melon allergy is oral allergy syndrome.

Anaphylaxis following ingestion of melon has been reported.

Occupational protein contact dermatitis due to melon has been described.