Insect sting allergy in adults: key messages for clinicians

During their lifetime, 94.5% of people are stung by wasps, honeybees, hornets, or bumble-bees (order
Hymenoptera). After a sting, most people show typical local symptoms, 5% to 15% develop local allergic
reactions, and 3% to 8.9%—systemic allergic reactions (SARs), which may be potentially life-threatening
in about 10% of them. In mild forms of Hymenoptera-venom allergy (HVA), the leading symptoms are
urticaria and edema (grades I and II, respectively, according to the Mueller classification). Severe SARs
are classified as grade III (respiratory symptoms) and IV (cardiovascular symptoms). Rare manifestations
of HVA are Kounis syndrome and takotsubo cardiomyopathy. All patients after an SAR require standard
(skin test, IgE, tryptase) or comprehensive (component diagnosis, basophil activation test) allergy testing.
All patients with severe systemic symptoms (hypertension, disturbances in consciousness) should be
tested for mastocytosis. Additionally, a relationship was found between the severity of HVA symptoms
and intake of angiotensin-converting enzyme inhibitors (ACEIs). There is a similar concern, although
less well-documented, about the use of β-blockers. Patients with HVA who have experienced a SAR are
potential candidates for venom immunotherapy (VIT), which is effective in 80% to 100% of individuals
treated for 3 to 5 years. An increased risk of a VIT failure has been reported in patients with systemic
mastocytosis and those treated with ACEIs. In certain groups (beekeepers, patients who develop a SAR
to stings during a VIT with a standard dose, as well as those with a SAR to maintenance doses of VIT),
a twice higher maintenance dose is recommended. Indications, contraindications, treatment protocols,
and vaccine doses are regulated by the international guidelines of allergy societies.