classification of severity of reaction to bee or wasp sting

Last reviewed 01/2018

Bees and wasps inject venom when they sting

  • when a person is stung by a bee or wasp they typically have an intense, burning pain followed by erythema (redness) and oedema (swelling) at the site of the sting
    • usually subsides within a few hours

    • after an initial sting, some people have an immune response and produce IgE antibodies. In these people, subsequent stings can trigger a rapid inflammatory response referred to as a 'type I' hypersensitivity reaction

      • hypersensitivity reactions to bee or wasp venom can be local or systemic, can vary in severity, and are typically of rapid onset
        • large local reactions are characterised by oedema, erythema and pruritus, cover more than 10 cm in diameter and peak at between 24 and 48 hours after the sting
        • systemic reactions can be measured using the Mueller grading system
          • severity ranges from grade I to grade IV
            • grade I systemic reaction is characterised by generalised urticaria or erythema, itching, malaise or anxiety

            • grade II reactions may include symptoms associated with grade I reactions as well as generalised oedema, tightness in the chest, wheezing, abdominal pain, nausea and vomiting, and dizziness

            • grade III reactions may include symptoms associated with grade I or II reactions as well as symptoms of dyspnoea, dysarthria, hoarseness, weakness, confusion, and a feeling of impending doom

            • grade IV reactions may include symptoms associated with grade I, II or III reactions as well as loss of consciousness, incontinence of urine or faeces, or cyanosis

        • guidelines for the treatment of bee and wasp venom allergy issued by the British Society for Allergy and Clinical Immunology classify systemic reactions as mild, moderate or severe

          • mild systemic reaction is characterised by pruritus, urticaria, erythema, mild angio-oedema, rhinitis and conjunctivitis

          • moderate systemic reactions may include mild asthma, moderate angio-oedema, abdominal pain, vomiting, diarrhoea and minor or transient hypotensive symptoms such as light-headedness and dizziness

          • severe systemic reactions may include respiratory difficulty such as asthma or laryngeal oedema, hypotension, collapse or loss of consciousness, as well as double incontinence, seizures, or loss of colour vision

          • anaphylaxis is defined by the European Resuscitation Council as a severe, life-threatening, generalised or systemic hypersensitivity reaction

Reference: