Mouse spider bites (Missulena spp.) and their medical importance

Abstract

To determine the clinical significance of definite bites by mouse spiders (Actinopodidae: Missulena spp.) from published case reports/series and museum records. A computerised literature search of MEDLINE and EMBASE was undertaken. All cases reported to major Australian museums and reports from venom researchers working with mouse spiders were also reviewed. Textbooks on clinical toxinology were searched and further reports of cases were located. All cases of definite spider bites where the spider was collected and identified by an expert as a mouse spider were included. All reports were evaluated and the following data extracted: patient demographics (age, sex, geographical location, season), bite site, local and systemic effects, and hospital attendance. Clinical effects were classified into three groups: severe neurotoxic envenoming, local neurotoxic effects or mild systemic effects, and minor local effects. Forty definite bites were identified from around Australia, with only one case of severe envenoming (a 19-month-old child). Local neurotoxic effects occurred in six cases and minor systemic effects in five. There was no evidence of envenoming in most bite victims, and the rate of severe envenoming was 2.5% (95% CI, 0-13%). There were no recorded deaths. In most cases, bites by mouse spiders cause only minor or moderate effects. Severe envenoming is rare and far less common than for funnel-web spider bites. Mouse spider bites do not appear to be a major medical problem.