White-tail spider bite: a prospective study of 130 definite bites by Lampona species.
OBJECTIVE
To investigate the circumstances and clinical effects of bites by white-tail spiders, including the two species Lampona cylindrata and L. murina commonly encountered by humans, and the incidence of necrotic lesions.


METHODS
Prospective cohort study of definite white-tail spider bites. Cases were only included if there was a clear history of bite, the spider was caught and was identified by an expert.


METHODS
Calls to Australian poisons information centres and emergency departments.


METHODS
130 patients with a definite bite by a white-tail spider from February 1999 to April 2002.


RESULTS
There were 79 bites by L. cylindrata and 51 by L. murina. Bites occurred in warmer months, 95% indoors and 75% between 16: 00 and 08: 00. The activity at the time of the bite was characteristic and the spider was encountered between bedclothes, towels or clothing. 25% of bites occurred on distal limbs. Pain/discomfort occurred in all cases, and was severe in 27%. Other effects included puncture marks (17%), redness/red mark (83%) and itchiness (44%). Systemic effects occurred in 9%. There were no cases of necrotic ulcers (97.5% CI, 0-2.8%) or confirmed infections. Median duration of effects was 24 hours (interquartile range, 1-168 hours). There were three distinct clinical patterns: pain only (21%), pain and red mark for < 24 hours (35%), and a persistent painful or irritating red lesion (44%).


CONCLUSIONS
Bites by Lampona spp. cause minor effects in most cases, or a persistent painful red lesion in almost half the cases. White-tail spider bites are very unlikely to cause necrotic ulcers, and other diagnoses must be sought.
Isbister
Geoffrey K
GK
Discipline of Clinical Pharmacology, University of Newcastle, Level 5, Clinical Sciences Building, Newcastle Mater Misericordiae Hospital, Waratah, NSW 2298, Australia. gsbite@bigpond.com
Gray
Michael R
MR
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D011446:Prospective Studies; D012621:Seasons; D012867:Skin / Q000473:pathology*; D001098:Spider Bites / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D013112:Spiders / Q000145:classification*