If one thing characterises food allergies is that they are extremely unpredictable. They appear when you least expect them to, disappear once you have learnt to live with them and can be caused by the most exotic or the most common foods. For a small but significant portion of the population, cutting out foods as common as pulses can prevent serious health problems. After egg, milk and fish allergies, and only just below fruit, come pulse allergies (accounting for around six percent of the total).

Why does it occur?
One of the reasons why pulses provoke allergies lies in their protein richness, something which also occurs with fruits and nuts, above all with almonds. It should not be overlooked that gluten intolerance sufferers also have the same problem with a type of protein present in some cereals. In the case of pulses, as in other leguminous crops, the problem appears to derive from a group of proteins called profilins. These can be found in fruit such as peaches, causing cross reactions that can also involve other families of food that may be the source of problems for those allergic to pulses. Soya beans may be one of the most nutritious and healthy of pulses, but it is also one of the grains that causes most reactions because not only do they appear when it is eaten in its original form but also when soya bean-derived goods are consumed, such as milk, tofu, shoots any other food that contains it as an additive or minor component.

Another characteristic of allergies to pulses is that they tend to be more common in children, as occurs with milk and eggs, as opposed to seafood and nut allergies, which are more prevalent in adults.

Symptoms
The symptoms of this type of allergy are very similar to those of other types:
- Stomach pain
- Diarrhoea
- Conjunctivitis
- Respiratory problems
- Eczema
- Fatigue and weakness

It is impossible to describe the seriousness of the symptoms because they vary considerably, or the amount of each food that is required for them to appear: a spoonful of beans or chick peas can be enough to bring them out.

Lentils: a special case
Certain pulses not only provoke allergies because of their nutritional aspect. A study carried out by Valladolid's Rio Hortera hospital has revealed that some people are especially sensitive to a small parasite found in lentils that is completely innocuous when swallowed, but when inhaled can cause eye and nasal problems. The origin of this allergy was discovered following tests on lentil allergy sufferers who stopped suffering when the parasite in question was removed. Researchers believe that this parasite is the cause of the recent increase in the number of lentil allergy sufferers. Previously lentils were sorted, and those containing this parasite (which looked a little off) were separated from those that did not. Currently, a fertiliser is used to paralyse the insect when the plant is still green, but which is not able to completely eliminate it.