Bees Wasps And Hornets

Stings from these flying insects are familiar to all. The stings, while painful, are of most concern in terms of anaphylaxis in hypersensitized persons. Honeybees (Apus spp.), who often lose their stingers when they envenomate, and bumblebees (Bombes spp.), who do not, usually will not bother people unless they are disturbed, excepting the easily provoked Africanized bees. Yellow-jackets, paper wasps, and hornets (Vespoidea) feed on nectar as adults, but feed their larvae insects. Vespids are seen at picnics and garbage dumps, attack without much provocation and retain their stingers, permitting repetitive stings (38).

The diagnosis of hymenopterism is straightforward, with accurate historical recollection by almost all patients. The painful, red, swollen sting usually resolves spontaneously in a few hours. Cold compresses and analgesics help, as does removing bee stingers. More extensive local allergic reactions can develop within two days and last a week; NSAIDs, antihistamines, cold compresses, and, if necessary, prednisone, will relieve symptoms.

Imported fire ants and the stings of bees, hornets, and wasps together cause over half the reported anaphylaxis cases (57). The cardinal signs are bronchial spasm, larangeal spasm, and hypotension. Within minutes of the sting, upper or lower airway obstruction occurs, the latter more frequent in asthmatics. Usually, pruritic wheals with red, raised, curved edges and white centers appear, focal or diffuse, that may become giant hives; these usually resolve by the second day. Occasionally, soft tissue swelling, as angioedema, is also present. Shock is often present, with or without a secondary cardiac event. Aspirin, opioids, NSAIDs, and radiocontrast agents must be avoided, as they may worsen matters. Upon recognizing anaphylaxis, inject 0.2 to 0.5 mL of 1:1000 epinephrine subcutaneously. Remove any insect stinger. Initiate an intravenous line to administer at 5 to 10 minute intervals 1:10,000 epi-nephrine and, should hypotension ensue, volume expanders and vasopressor agents. Nasal oxygen may be useful, but intubation or tracheostomy must be used to treat progressive hypoxia (58). Rapid transit to a hospital is critical. Immunotherapy with insect venom effectively prevents future events; referral to an allergist is vital (59). Patients must be provided and taught to use Epipens. Discussions with the employee and the employer are important to reduce the hazards and consider transfer to a job without such risk factors.

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