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

Lima Bean Allergy Test: Allergen Exposure

Lima beans originated in South America, and were domesticated around 4,000 years ago. They were introduced to Europe by explorers around the 16th century, taking their name from the port of origin of most shipments, Lima in Peru.

Both bush and climbing variants exist, each producing pods of around 15cm containing several flat, kidney shaped seeds of between 10 and 30mm in length.

The most common variety produces white seeds, although black, orange, red and mottled seeds are also seen.

Like many other legumes, lima beans are a good source of fibre, contain virtually no fat, and are an excellent source of high-quality protein. They also contain high to moderate levels of folate, phosphorus, protein, potassium, vitamin B1, iron, magnesium and vitamin B6.

The raw beans contain toxins, and therefore must be boiled in water for at least 10 minutes before they are suitable for consumption. These include cyanide, trypsin inhibitor, lectin, phytin and tannin. For convenience, precooked lima beans are commonly available canned which reduces the necessary preparation time and avoids any risk of exposure to these toxins.

Once safely cooked, lima beans can be consumed alone, or as an ingredient in soups, salads or other dishes. They are frequently combined with rice or pasta, or served mixed with corn as in the North American dish succotash.

Lima Bean Allergy Test: Allergen Description

Studies have demonstrated that lima beans contain at least 23 proteins which may have allergenic potential, although no allergens have been characterised.

Lima Bean Allergy Test: Potential Cross-Reactivity

Reports suggest cross-reactivity between lima beans and other allergenic legumes, such as soya, peanut, and black gram.

However, studies have demonstrated that although the degree of cross-reactivity among members of the legume family is high, the clinical significance of this is low. Therefore being allergic to one legume does not necessarily require excluding other legumes from the diet.
This is supported by a study which reported on a 33-year-old woman who developed tongue swelling and burning and mouth itching within minutes of eating baked beans. Similar symptoms occurred following ingestion of other legume products, including peas, a bean burrito, and kidney and pinto beans, but not lima beans, confirming that cross-reactivity between the legumes is not absolute.

Cross-reactivity has been demonstrated between Mesquite tree pollen and lima bean.

Lima Bean Allergy Test: Clinical Experience

Lima bean may induce symptoms of food allergy in sensitised individuals, although this is uncommon, however, a number of studies have demonstrated sensitisation to Lima bean.

In a survey of food allergy among asthma and rhinitis patients in India, when allergy to Lima bean was claimed via patient history, sensitisation to Lima bean was demonstrated in approximate 3-4% cases.