Legume Allergy: lentils, chickpeas, peas, beans, and peanuts

This Spanish study included 54 children with allergic reactions after exposure to legumes. Legumes were defined as lentils, chickpeas, peas, white beans, and peanuts.

The diagnosis of legume allergy was confirmed by positive skin prick test with legume extracts and food challenges, or a recent convincing history of severe reactions.

The onset of allergic reactions was at 2 years.

Allergy to lentil was the most frequently diagnosed legume allergy (80%), followed by allergy to chickpea (59%).

In conclusion:

- lentils and chickpeas are the legumes that cause most allergic reactions
- allergy to more than 1 legume is common
- boiled legume extracts provided the best results

Practical perspective

Oral allergy syndrome may also play a role when symptoms occur with legumes. For example, patients allergic to grasses may have symptoms with peanut and legumes. There is also cross-reactivity in food allergy to peanut - 5% of patients with peanut allergy may have symptoms with legumes.



Food allergy management in 4 steps (click to enlarge the image).

The common sequence of the workup is:

1. skin test with commercial extracts for lentils, chickpeas, peas, beans, and peanut
2. ImmunoCAP sIgE for as lentils, chickpeas, peas, beans, and peanut
3. If ImmunoCAP is negative, perform a prick-puncture test with fresh boiled lentils, chickpeas, peas, beans, and peanuts
4. If the prick-puncture test is negative, there is approximately 90% chance of a negative food challenge. If the challenge in the allergy clinic is negative, then food allergy can be excluded.

References:

Clinical features of legume allergy in children from a Mediterranean area. Martínez San Ireneo M, Ibáñez MD, Sánchez JJ, Carnés J, Fernández-Caldas E. Ann Allergy Asthma Immunol. 2008 Aug;101(2):179-84.

Pea Allergy

Image source: Frozen green peas. Wikipedia, Jina Lee, GNU Free Documentation License.