SERIOUS gaps in knowledge make it difficult to precisely identify risk factors for severe allergic reactions to food. Researchers at Imperial College London, UK, have assessed 88 studies surrounding the severity of allergens to food.
Lead study author, Paul Turner, National Heart and Lung Institute, Imperial College London, UK, reviewed studies published between January 2010 and August 2021 with his research team. Thirteen studies indicated that prior anaphylaxis was a poor predictor in assessing future risk for severe reaction to food allergens. Thirty-four studies found that a patient diagnosis of asthma was not a risk factor for severe allergic reactions. Twenty-five studies demonstrated that IgE-sensitisation accurately predicts the severity of allergens. Thirty-three of the included studies established that both food processing and ingredients have an effect upon allergens and their associated symptoms; however, data proved limited. Six papers concluded that the use of angiotensin-converting enzyme inhibitors and β-blockers can increase the severity of allergens. However, factors such as age, mast cell disease, and exposure to other allergen triggers have more impact on allergen severity.
Studies showed that a higher number of people experiencing fatal reactions to allergens occurred away from home. Many of the studies also corroborated an association between risk for anaphylaxis from food allergens and age. Children between 0–4 years are at the greatest risk of developing anaphylaxis; adolescents and adults who are younger than 40 years had the greatest risk for near-fatal and fatal anaphylaxis, although this outcome is low. However, researchers concluded that a lack of prior anaphylaxis was not an indicator for a lower severity risk.
The team observed that their review of the literature shows that much needs to be learnt about risk factors for anaphylaxis and severe reactions to food allergies. They also noted that their findings challenge current conventions, which purport that a diagnosis of asthma is an important predictor in allergen severity. Researchers stressed that individuals with low-risk food allergies are still at risk of anaphylaxis and their allergens need to be appropriately managed.
