White-tail spider bite not so black
EMBARGOED UNTIL 12.00 MIDDAY SUNDAY 17 AUGUST 2003
A world-first study published in the current issue of the Medical Journal of Australia shows that of the 130 white tail spider bite victims, who called poisons information centres or presented at emergency departments, none suffered from these ulcers or from confirmed infection.
Dr Geoff Isbister, from the Clinical Envenoming Research Group at the University of Newcastle, and Dr Mike Gray, Senior Research Scientist at the Australian Museum, examined the effects of bites by two species of white-tail spider - Lampona cylindrata and L. murina.
Several reports of necrotic lesions have been published in the past 20 years, despite lack of evidence of an identified white-tail spider biting the patient.
"In our study, cases were only included if there was a clear history of bite, the spider was caught and was identified by an expert," Dr Isbister said.
The prospective cohort study included 130 patients who'd been bitten by a white-tail spider from February 1999 to April 2002.
"Most bites occurred in the warmer months in southern Australia, indoors, in the evening and at night. The spider was usually encountered between bedclothes, towels or clothing," Dr Isbister said.
"A quarter of bites were to hands and feet, almost half were on the arm or leg. Twenty seven per cent of people were bitten on the trunk and six per cent were bitten on the head or face. Pain or discomfort was felt in all cases. Pain was severe (worse than a bee sting) in 27 per cent of cases. Patients also suffered from redness and itchiness.
"Most people suffered symptoms for up to 24 hours and almost half had a persistent painful or irritating red lesion.
"But there were no cases of necrotic ulcers or confirmed infections. Other diagnosis should be sought for these symptoms.
"We hope this study will begin to dispel some of the myths surrounding white-tail spiders and their bite," Dr Isbister said.
Also included in this issue of the MJA is editorial comment on the study.
The Medical Journal of Australia is a publication of the Australian Medical Association.
CONTACT: Dr Geoff Isbister, 0438 466 471 (until 7.30 am on Monday)
Judith Tokley, AMA, 02 6270 5471/0408 824 306