Hypersensitivity to members of the botanical order Fabales (legumes)

Legumes are an important source of proteins and their consumption is very frequent in the Mediterranean region and in some Asian and African countries. In some of these regions, lentils and chickpeas are one of the main food allergens. Legumes are also used as food additives due to their emulsifying properties and can be present in many manufactured foods. These hidden food allergens have the potential of causing adverse reactions in legume-sensitive subjects. The allergenic composition of various legumes has been investigated. They have been found to contain multiple allergens, a few of which have been cloned and sequenced. Legumes contain acid-resistant and thermostable allergens. There is a significant degree of cross-reactivity among legumes, the clinical relevance of which seems to be dependent on the dietary habits in different communities. In Spain, the consumption of several legumes is frequent and, therefore, clinical allergy to more than one species in children is common. Clinical manifestations include cutaneous, digestive and respiratory symptoms. Legumes can cause life-threatening reactions in sensitized individuals. Inhalation of steam, powder or flour from some legumes may cause respiratory diseases such as rhinitis, asthma and hypersensitivity pneumonitis. Soybean allergy is generally transitory, but clinical allergy to peanuts is rarely outgrown. The natural history of other legume allergies is less known and more studies are necessary to reach definite conclusions.