Anaphylaxis: insects, drugs and food were common causes

Clinical bottom line (level 4)

  1. Anaphylaxis was uncommon.
  2. Drugs that commonly caused anaphylaxis include glaphenine, amoxicillins, penicillins, diclofenac and other NSAIDs.
  3. Common causes of anaphylaxis were insect stings/bites, drugs and food.
van der Klauw et al: British Journal of Clinical Pharmacology 1993; 35: 400-408
Expires November 2004

The study

Case-control study with blinded outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: the Netherlands

250000 patients (aged ?, ?% male) taking medication in 1987 to 1988

Excluded if
  • reaction due to something bought or encounter outside the Netherlands
  • lack of clinical information
  • clinician refused to participate or considered admission not relevant


    • Cases: 336 patients (47% male, mean age 43): with anaphylaxis (defined as probable or possible by a panel of 3 blinded clinicians)
    Controls: 150000 patients (% male, mean age ): taking medication from 28 representative pharmacies


    Outcomes studied:
  • possible or probable anaphylaxis in 1988

    • The evidence

    Patient expected event rate for possible or probable anaphylaxis in 1988: 0.022%
    risk factor for
    possible or probable anaphylaxis in 1988     		unadjusted RR
    (95% CI)    		 NNH
    (95% CI)
    glaphenine 53.8
    (25.5 to 113.2)     		87
    (42 to 190)
    amoxicillins 2.37
    (0.74 to 7.57)     		410
    (190 to 920)
    diclofenac 8.21
    (3.73 to 18.1)     		630
    (270 to 1700)
    penicillins 7.28
    (3.78 to 14.0)     		730
    (350 to 1600)
    NSAID 4.19
    (2.06 to 8.51)     		1400
    (600 to 4300)
    analgesics 3.78
    (1.91 to 7.46)     		1600
    (700 to 5000)

    • 252 patients had a probable or certain causal relationship
      • insects: 48% (95% CI: 42% to 54%)
      • drugs: 42% (95% CI: 36% to 49%)
      • food: 8.3% (95% CI: 4.8% to 12%)
      • miscellaneous: 1.6% (0.0% to 3.1%)
    • The commonest drug reactions were
      • glaphenine 19% (95% CI: 11% to 26%)
      • amoxicillins 11% (95% CI: 5.2% to 17%)
      • diclofenac: 7.5% (95% CI: 2.5% to 13%)
      • analgesics with paracetamol: 6.5% (95% CI: 1.9% to 11%)
    • Similar results were obtained in 1987, except for Amoxicillin (RR 12.3; 95% CI 5.94 to 25.3)

    Comments

    1. Cases and controls were not clearly similar to each other, though controls matched demographics of the Dutch population
    2. Failure to adjust for confounding factors makes these results less certain.

    Citation

    1. van der Klauw MM, Stricker BH, Herings RM, et al: a population based case-cohort study of drug-induced anaphylaxis. British Journal of Clinical Pharmacology 1993; 35: 400-408
    Contributor: Mike Bennett and Chris Ball, November 1999
    Reviewer: Malcolm Daniel

    Clinical Question.
    Patient patients taking medication
    Intervention or Exposure common causes / drug causes
    Outcome anaphylaxis