Nuts are a strong allergen and differ from peanuts, which are a legume and are part of the peas, beans and soy family. Many peanut allergic patients are also nut sensitive.
Nuts are strong allergens but not every reaction is life-threatening. We cannot predict who will have a threatening reaction.
When children become allergic to a food, it is usually during the first two years of life, often the first time they are fed the food. After age 3 it is less common to become allergic to a food. Nut sensitivity tends to persist and can occur late in life.
Nut allergy is not as common as sensitivity to egg and milk. However nut reactions can be threatening more often than reactions to milk or egg. Nuts are also commonly found in confectioneries and are a common foodstuff in North America. Children with asthma are at more risk of a serious reaction.
Occasionally children can outgrow sensitivity to nut but this occurs less commonly than with milk and egg. If the skin test to a nut is negative then we test to several preparations of nuts and perhaps the fresh nut itself. If the skin tests are negative we will confirm with a blood test and then go ahead with an oral challenge. It is worth evaluating in infancy to confirm the reaction, then school age and finally in the teen years.
Pure nut oils e.g. coconut are not a problem but some oils (i.e. cold-pressed) are crude and contaminated with nut protein which results in reactions in nut-allergic individuals.
Some packages have a warning that the food may contain nut. These are usually foods that are not intended to include the nut but are prepared in equipment that has been used to prepare other nut-containing foods.
Caregivers must be taught the management of a nut-allergic child and must be comfortable with the use of the EpiPen. When a reaction occurs, there should be no hesitation about administering the adrenaline and the child should be transported to an emergency department. It is safer to give adrenaline than not give it. Anti-histamines do not deal with the major symptoms of a reaction.