Systemic reactions to wasp sting: Is the clinical pattern related to age, sex and atopy?

Background: The aim of this study was to analyze the frequency of clinical features and the severity of systemic reactions to wasp stings, and to establish their relationship with mean age, sex, and atopy. Methods: We studied 115 patients who suffered an anaphylactic reaction to wasp sting and showed specific IgE to venoms from Vespula and/or Polistes. In all patients, age, sex and personal history of atopy were registered. Cutaneous, respiratory, cardiovascular and gastrointestinal involvement during the course of the reaction was investigated. Each patient was assigned a severity grade according to a simple two-grade classification based on Muller's criteria. Bivariable analysis was performed to analyze the associations among mean age, sex and atopy and the symptoms and severity of the reaction. Results: The mean age was 40.2 years. There were 60 males (52.2%) and 55 females (47.8%). Twenty-six patients (22.6%) were atopic. The percentages of involved systems were as follows: skin 90.4%, respiratory 54.8%, cardiovascular 33.9%, and gastrointestinal 21.7%. Reactions were mild in 40.8%, and severe in 59.1%. The mean age was higher in patients without cutaneous symptoms (p<0.05). Cardiovascular involvement was more frequent in males (p<0.05). No other significant differences were found. Conclusion: The symptoms of systemic reactions to wasp venom most frequently involved the skin, while reactions without cutaneous involvement were more frequent in older patients. Cardiovascular involvement was more common in males. The clinical pattern was not determined by atopy and the variables studied were not related to severity.