title: The incidence and features of systemic reactions to skin prick tests.
abstract: BACKGROUND
  Skin prick testing (SPT) has been regarded as a safe procedure with few systemic reactions.
  
  
  OBJECTIVE
  To evaluate the rate of systemic reactions and their associations after SPT in the largest population to date.
  
  
  METHODS
  In this study reactions were recorded prospectively in a specialist UK allergy clinic for 6 years (2007-2013). An estimated 31,000 patients underwent SPT.
  
  
  RESULTS
  Twenty-four patients (age range 7 months to 56 years, mean 23.5 years, 17 female patients, 12 with asthma) had systemic reactions. The rate of systemic reactions to SPT was 0.077%. The likely allergens causing the reaction were foods (18; peanut, 7; walnut, 1; Brazil nut, 2; pistachio, 1; lupin, 1; cow's milk, 2; shrimp, 1; spinach, 1; legume, 1; soy, 1), aeroallergens (4; rabbit, 1; rat, 1; ragwort, 1; grass pollen, 1), wasp venom (1), and Tazocin (1). The causative SPT wheal was larger than 8 mm in 75%. The reaction to Tazocin was severe, with anaphylaxis occurring minutes after SPT. Reactions were treated immediately in the clinic and did not require further medical care.
  
  
  CONCLUSIONS
  In this largest single-center study, the rate of systemic reactions after SPT was 77 per 100,000 patients. It is the first study to identify foods as a common and important cause (75%), with nuts posing the highest risk. This study reports the first systemic reaction to venom SPT and the first anaphylactic reaction after drug SPT. There was an association with a history of severe reactions and large skin test reaction. There are risks, albeit small, when undertaking SPT.
authors.affiliation: Department of Allergy, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom. Electronic address: priya.sellaturay@addenbrookes.nhs.uk.
authors.forename: Priya
authors.initials: P
authors.lastname: Sellaturay
authors.affiliation: Department of Allergy, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Shuaib
authors.initials: S
authors.lastname: Nasser
authors.affiliation: Department of Allergy, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom.
authors.forename: Pamela
authors.initials: P
authors.lastname: Ewan
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D000707:Anaphylaxis / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004890:Erythema / Q000276:immunology; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D021184:Nut Hypersensitivity / Q000276:immunology; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000276:immunology; D010878:Piperacillin / Q000276:immunology; D000077725:Piperacillin, Tazobactam Drug Combination; D011446:Prospective Studies; D012189:Retrospective Studies; D012882:Skin Tests / Q000009:adverse effects*; D014581:Urticaria / Q000276:immunology; D055815:Young Adult
chemical_list: D000485:Allergens; D000077725:Piperacillin, Tazobactam Drug Combination; D010397:Penicillanic Acid; D010878:Piperacillin