Allergy to Hymenoptera venom

Hymenoptera (bees, wasps, hornets, polistes) are most important in allergology, because of their inherent danger.

An allergy to hymenoptera venom can cause local reactions (3.1-17%) or severe generalized reactions (0.15-3.3%), such as respiratory or cardiovascular reactions that may cause death.

It is still difficult to estimate the proportion of subjects allergic to hymenoptera venom as deaths from bites/stings are often diagnosed as due to cardiac arrest and not to anaphylactic shock.

Risk factors for severe systemic reactions are: the season (summer), the site of the bite/sting (those to the face are the most dangerous), age (elderly), type of allergen (bee venom is more dangerous than wasp venom), the presence of concomitant heart or respiratory disease, alcohol consumption.

A local reaction characterized by redness and swelling at the site of the sting/bite that is smaller than 5 cm should be considered a normal.

Generalized reactions can affect the respiratory system (asthma, edema of the glottis), the circulatory system (anaphylaxis), the digestive system (nausea and vomiting) and the skin (urticaria/angioedema).

To diagnose an allergy to hymenoptera venom, tracing back to the responsible insect is of fundamental importance. The patient is then subjected to skin tests with purified extracts of the most common venoms in our area (Apis mellifera, Vespula species, Polistes species, Vespa Crabro) and to a radioallergosorbent test (RAST), which allows for quantification of the circulating antibodies.

The most appropriate treatment for hymenoptera venom-allergic patients is immunotherapy (vaccine) in cases of generalized reactions and in high-risk groups (farmers, beekeepers, etc.). Immunotherapy should be carried out for a period of at least 5 years. The cumulative effectiveness determines the highest level of satisfaction for the patient and the specialist.

In all cases, it is essential that the patient allergic to hymenoptera venom always carries an allergy rescue kit, containing adrenaline, steroids and antihistamines, which can be self-administered.