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The Australian white-tailed spiders (“WTS”; Lamponidae: notably Lampona cylindrata & Lampona murina) have a continuing reputation on Internet sites as a cause of skin ulceration, labelled “necrotic arachnidism”, despite an increasing number of peer-reviewed publications debunking this reputation, with >135 confirmed cases now reported without any evidence of necrosis. We present here a case of confirmed WTS bite in a 42-year old male, followed for over a month, with photos of bite site signs and no development of skin ulceration/necrosis. The patient was initially alarmed by information on the Internet suggesting local necrosis would result from the bite. We discuss the evolution of knowledge about bites by the WTS, and the persistence of misconceptions about their factually mild medical significance.

Specialist true predators are expected to exhibit higher capture efficiencies for the capture of larger and dangerous prey than generalist predators due to their possession of specialized morphological and behavioral adaptations. We used an araneophagous spider (Lampona murina) and a generalist spider (Drassodes lapidosus) as phylogenetically related model species and investigated their realized and fundamental trophic niches and their efficacy with respect to prey capture and prey handling. The trophic niche of both species confirmed that Lampona had a narrow trophic niche with a predominance of spider prey (including conspecifics), while the niche of Drassodes was wide, without any preference. DNA analysis of the gut contents of Lampona spiders collected in the field revealed that spiders form a significant part of its natural diet. Lampona captured significantly larger prey than itself and the prey captured by Drassodes. As concerns hunting strategy, Lampona grasped the prey with two pairs of legs possessing scopulae, whereas Drassodes immobilized prey with silk. Lampona possess forelegs equipped with scopulae and a thicker cuticle similar to other nonrelated araneophagous spiders. Lampona fed for a longer time and extracted more nutrients than Drassodes. We show that specialized behavioral and morphological adaptations altogether increase the hunting efficiency of specialists when compared to generalists.

Objectives: To identify and demonstrate necrotizing dermatitis in infancy; an uncommon, puzzling syndrome, in which anecdotal reporting and personal experience indicates that one third of cases may require skin grafting. Much informed discussion about the pathogenesis of this distressing syndrome centres on the role of spider envenomation; and in particular on the speculative role of the Australian White-tailed spider, Lampona cylindrata. Methods: We present here six cases of necrotizing dermatitis treated surgically at the Royal Children's Hospital and Mater Children's Hospital in Brisbane over the period from 1991 to 1999. Clinical history, surgical details and pathological investigations were reviewed in each case. Microbiological investigation of necrotic ulcers included standard aerobic and anaerobic culture. Result: Nocardia and Staphylococcus were cultured in two cases, but no positive bites were witnessed and no spiders were identified by either the children or their parents. All cases were treated with silver sulphadiazine creme. Two of the infants required general anaesthesia, excision debridement and split skin grafting. The White-tailed spider, Lampona cylindrata, does not occur in Queensland, but Lampona murina does; neither species has necrotizing components in its venom. Circumstantial evidence is consistent with this syndrome being due to invertebrate envenomation, possibly following arachnid bites. Conclusion: In our experience there is insufficient evidence to impute a specific genus as the cause, at this stage of scientific knowledge. If the offending creature is a spider, we calculate that the syndrome of necrotizing dermatitis occurs in less than 1 in 5000 spider bites.

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.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.Calls to Australian poisons information centres and emergency departments.130 patients with a definite bite by a white-tail spider from February 1999 to April 2002.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 for24 hours (35%), and a persistent painful or irritating red lesion (44%).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.

Necrotising arachnidism, or skin ulceration due to spider bite, is an unresolved clinical problem in Australia, with both the spiders responsible and disease pathogenesis remaining unclear. We have examined and compared enzymic activity from three species of Australian spiders capable of causing ulceration in humans; the recluse spider (Loxosceles rufescens), the black window spider (Badumna insignis) and the white-tailed spider (Lampona cylindrata). Enzymes which could contribute to skin ulceration, namely hyaluronidase and proteases, were detected in venom extracts of all the three spiders. Significant sphingomyelinase activity was detected in L. rufescens venom and in abdominal extracts from the three spider species, while significantly lower levels of sphingomyelinase activity were detected in abdominal extracts from the non-necrosing red-back spider (Latrodectus hasselti). These results suggest that both venom and gastric enzymes may contribute to the dermonecrotic effects of these spiders bites.

Objectives: To analyse the clinical features and outcomes of patients with spider bites who presented to the Department of Emergency Medicine, Royal Hobart Hospital, Tasmania, Australia. Methods: A retrospective study of all patients with an emergency department discharge diagnosis of confirmed spider bite during a 5 year period was performed. Results: Twenty-two cases were identified, 15 of which involved unidentified spiders. Most victims were in the 15–34 years age group and were bitten in the home. Identified spiders included: redback (Latrodectus hasselti), white-tailed house (Lampona cylindrata), black house (Badumna insignis) and huntsman (Delena cancerides). Pain, swelling and erythema were the main presenting symptoms; main presenting signs were erythema, swelling, bite marks, local tenderness, lymphadenopathy and blistering. In 23% of cases, no clinical signs were detectable. Treatment consisted of antihistamines (36%) and antibiotics (32%). Four patients had signs consistent with necrotizing arachnidism; two of the four healed with hyperbaric oxygen after antibiotic treatment failed. Redback antivenom was administered to four patients. Three patients required in-patient treatment for local complications. Conclusions: Most spider bites presenting to Royal Hobart Hospital were uncomplicated; redback bites were uncommon. Treatment strategies were ill-defined and microbiological specimens were taken infrequently. Patients’ tetanus immunization status was poorly documented. There is a need for a national register of spider bites in Australia.

Experiments were performed using an anaesthetised rat model to investigate the local inflammatory responses produced by intradermal injections of crude venom gland extracts from a number of Australian spiders, namely, Phonognatha graeffei, Delena cancerides, Isopeda montana, Badumna insignis, Lampona cylindrata, Steatoda grossa, S. capensis Hann. All of the venom gland extracts tested, with the exception of that from S. capensis, produced increases in vascular permeability consistent with acute inflammatory responses. The responses primarily involved the activation of 5-HT receptors, since they were markedly reduced by the nonselective 5-HT1/5-HT2-receptor antagonist methiothepin. Some of the venoms caused liberation of endogenous mediators of inflammation, and some had components that acted directly on the vasculature to increase vascular permeability. Histamine appeared to have little if any role in the observed increases in vascular permeability following intradermal injection of the spider venoms.

1. Venom samples from twelve different Australian spider species were compared for their toxic effects on the heart and respiratory systems of anaesthetized rats. 2. The first and most serious effect of all venoms was on breathing, cardiotoxicity mostly being secondary to respiratory failure. 3. Only Atrax infensus and Selenocosmia stirlingi venoms proved highly toxic to rats, and therefore potentially toxic to humans, when single doses were used. 4. The low potency of most of the other venoms tested showed that several simultaneous spider bites would be necessary to cause significant toxicity.

Lampona lomond, new species Figures 82–85; Map 5 TYPES: Female holotype and male allotype taken in open forest at an elevation of 1000 m in Ben Lomond National Park, 418309S, 1478389E, Tasmania (Feb. 5, 1987; J. Gallon), deposited in QMB (S11633). ETYMOLOGY: The specific name is a noun in apposition taken from the type locality. DIAGNOSIS: This species resembles L. talbingo (see above) but can be distinguished by the longer tibial apophyses of males (figs. 82, 83) and the shorter spermathecae of females (figs. 84, 85). MALE: Total length 5.6. Abdominal coloration as in L. cylindrata. Anterior legs with darkened femora and tibiae; posterior legs with distal three­fourths of femora, patella, tibiae, distal one­fourth of metatarsi darkened. Palpal femur with subbasal knob protruding from ventral surface; tibia with two retrolateral tibial apophyses, ventral one wide basally, bent distally at right angle, followed dorsally by smaller, long apophysis (fig. 83); tegulum globose, extending to half length of tibia, embolus recessed behind conductor (fig. 82). FEMALE: Total length 8.2. Coloration as in male. Epigynum elongated, with rounded anterior and lateral rims surrounding shallowly depressed fossa bearing elevated ridge at about half its length (fig. 84); spermathecae with tiny anterior portion (fig. 85). OTHER MATERIAL EXAMINED: New South Wales: Mount Kosciusko, 368279S, 1488169E, Dec. 1931, elev. 5000–6000 ft (P. Darlington, MCZ), 1 /; Perisher Valley, 368259S, 1488259E, Jan. 20, 1975, under stones (V. Salanitri, QMB S26768), 1/. Tasmania: Ben Lomond National Park, 418309S, 1478389E, Feb. 5, 1987, open forest, elev. 1000 m (J. Gallon, QMB S11633, 11636), 2 /; Derwent Bridge, 428089S, 1468149E, Dec. 22, 1997. eucalypt bark, open eucalypt forest (L. Boutin, TMH), 1 /; Dry’s Bluff, 418429S, 1468499E, Dec. 31, 1929, in silk nest under stone on summit, elev. 4125 ft (V. Hickman, AMS KS28932), 1 /; Forth Falls, 418239S, 1468139E, Dec. 28, 1926 (V. Hickman, AMS KS29317), 1 /; Great Lake, 418529S, 1468459E, Mar. 19, 1930, under stone (V. Hickman, AMS KS31859), 1/, Jan. 22, 1940, under log (V. Hickman, AMS KS28959), 1/, Nov. 20, 1972 (M. Baehr, CBB), 1 /; Interlaken, 428099S, 1478109E, Mar. 1938, under lichens (V. Hickman, AMS KS31864), 1 /; Lake Augusta, 418529S, 1468329E, Nov. 21, 1972 (M. Baehr, CBB), 3 /; Lenah Valley, 428529S, 1478179E, July 28, 1951, under stone (V. Hickman, AMS KS44051), 1 /; Mount Barrow, summit, E Launceston, 418229S, 1478259E, Feb. 5, 1987, heath plain, elev. 1300 m (R. Raven, T. Churchill, QMB S11679), 2 /; Mount Field National Park, 428419S, 1468499E, Jan. 1, 1998, under rocks (L. Boutin, TMH), 1/ (penultimate but with formed epigynum); near Mount Field National Park, 428419S, 1468439E, May 1996, under bark, elev. 160 m (L. Boutin, TMH), 1 /; Mount Wellington, 428549S, 1478149E, Dec. 1956, high (P. Darlington, MCZ), 1/, Dec. 10, 1963, summit, with eggsac under stone (J. Hickman, AMS KS31863), 1 /; Nive River, 15 km N Bronte Park, 418409S, 1478189E, Nov. 24, 1972 (M. Baehr, CBB), 2 /; southwestern Tasmania, 428559S, 1458539E, Feb. 15, 1978, hand collecting, heathland transect (L. Hill, AMS KS27058), 1 /; Spring Hill, 428249S, 1478159E, Sept. 6, 1947, in grass tussocks (V. Hickman, AMS KS44041), 1 /; Strahan, 428099S, 1458199E, Nov. 14–Dec. 1, 1997, eucalypt bark (L. Boutin, TMH), 2 /; Tomahawk River, 40 km NE Scottsdale, 418099S, 1478319E, Nov. 3, 1972 (M. Baehr, CBB), 1/. Victoria: Cobon North Coupe, site 512.08, Vaus experimental study, 378229S, 1488569E, Apr. 6–10, 1992, upslope pitfalls (R. Coy, NMV K3556), 1?; Mount Hotham, 368589S, 1478079E, Dec. 13, 1962, elev. 1700 m (E. Ross, D. Cavagnaro, CAS), 2 /. DISTRIBUTION: Southeastern Australia, including Tasmania (map 5)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on pages 51-52, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

Lampona hickmani, new species Figures 154, 155; Map 15 TYPE: Female holotype taken under bark on Mount Wellington, 428549S, 1478149E, Tasmania (Aug. 19, 1924; V. Hickman), deposited in AMS (KS29253). ETYMOLOGY: The specific name is a patronym in honor of the collector, the late Dr. V. Hickman. DIAGNOSIS: Females resemble those of L. pusilla but have longer lateral margins of the epigynal midpiece (fig. 154) and almost obsolete anterior portions of the spermathecae (fig. 155). MALE: Unknown. FEMALE: Total length 8.5. Abdomen brownish gray, without distinct pattern; legs unmarked. Epigynum with indistinct anterior margin, with v­shaped midpiece greatly widened anteriorly (fig. 154); spermathecae tripartite, anterior portion tiny, almost obsolete (fig. 155). OTHER MATERIAL EXAMINED: Four females taken with the holotype. DISTRIBUTION: Known only from Tasmania (map 15)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on page 78, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

Lampona monteithi, new species Figures 242–245; Map 28 TYPE: Female holotype taken at an elevation of 1100 m at a site 3 km W Bones Knob, 178139S, 1458259E, Queensland (Dec. 10, 1995; G. Monteith, D. Cook, G. Thompson), deposited in QMB (S28538). ETYMOLOGY: The specific name is a patronym in honor of Dr. Geoff Monteith of the Queensland Museum, whose indefatigable collecting has vastly improved our knowledge of the Queensland lamponid fauna. DIAGNOSIS: Males resemble those of L. kirrama but have an unmodified palpal femur (fig. 243); females have a distinctively arched and elevated anterior epigynal margin (fig. 244). MALE: Total length 5.8. Abdominal dorsum with anterior pair of longitudinal white stripes connected to median transverse white band, band with posterolateral white extensions almost reaching transverse posterior white band; femora with distal, tibiae with proximal and distal slightly darkened rings. Palpal femur short, unmodified; retrolateral tibial apophysis sinuous, with tip directly distodorsally (fig. 243); tegulum not enlarged, extending posteriorly only slightly past base of tarsus; embolus small, recesses behind conductor (fig. 242). FEMALE: Total length 9.2. Abdominal dorsum with median pair of white spots fused medially, extended anteriorly along midline; leg coloration as in male. Epigynum with arched, elevated anterior margin (fig. 244); spermathecae tripartite, middle portion largest (fig. 245). OTHER MATERIAL EXAMINED: Queensland: Hugh Nelson Range, 178279S, 1458299E, July 3–Aug. 1, 1995, intercept trap, elev. 1150 m (P. Zborowski, QMB), 1?; Lambs Head, 10 km W Edmonton, 178029S, 1458389E, Dec. 4, 1988, rainforest (G. Monteith, G. Thompson, QMB S34281), 1?; Massey Creek, 178379S, 1458349E, Jan. 3–Feb. 4, 1995, pitfall, elev. 1000 m (P. Zborowski, QMB), 1?; Summit TV station, Bellenden Ker Range, 178169S, 1458519E, Nov. 1–7, 1981, pyrethrum knockdown on logs, stones, and tree trunks, elev. 1560 m (ex QMB S28087), 1?. DISTRIBUTION: Known only from northern Queensland (map 28)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on page 111, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

Lampona whaleback, new species Figures 90–93; Map 6 TYPE: Female holotype taken in dry pitfall trap on Mount Whaleback, 238219S, 1198399E, Western Australia (Aug. 7–12, 1997; D. Knowles), deposited in WAM (96/ 1525). ETYMOLOGY: The specific name is a noun in apposition taken from the type locality. DIAGNOSIS: This species resembles L. lomond in having a subbasal knob on the palpal femur, but differs in having a shorter retrolateral tibial apophysis in males (fig. 91) and anterolateral epigynal invaginations in females (fig. 92). MALE: Total length 7.0. Abdominal dorsum with only posterior white spot clearly marked, with only vague indications of anterior white spots, venter palp gray, without markings; legs with posterior tibia distolaterally darkened. Palpal femur with distinct subbasal knob, retrolateral tibial apophysis situated near ventral edge of segment, accompanied by short, more dorsal apophysis (fig. 91); embolus with long, retrolaterally curved tip (fig. 90). FEMALE: Total length 8.8. Abdominal dorsum with four anterior white spots each almost rectangular, leg coloration as in male. Epigynum with v­shaped median septum separating anterolateral depressions marked by strong ridges (fig. 92); spermathecae with conical basal portion, rounded distal portion, situated between lateral invaginations (fig. 93). OTHER MATERIAL EXAMINED: The single male here associated with the type was taken in a pitfall trap at Bush Bay, 258079S, 1138489E, Western Australia, Jan. 16–May 23, 1995 (P. West, WAM 96/1524). DISTRIBUTION: Western Australia (map 6)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on page 55, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

Lampona chalmers, new species Figures 102–105; Map 7 TYPE: Female holotype taken in a pitfall trap at C. Hollins on Mount Chalmers, 238189S, 1508389E, Queensland (Mar. 16, 1993; D. Wallace), deposited in QMB (S22184). ETYMOLOGY: The specific name is a noun in apposition taken from the type locality. DIAGNOSIS: Both sexes can be recognized by their distinctively dark coloration, males by the prolaterally hooked tip of the retrolateral tibial apophysis (figs. 102, 103), and females by their heart­shaped epigynal atrium (fig. 104). MALE: Total length 5.0. Abdominal dorsum almost black, with five white spots reduced to narrow transverse bands; distal portions of femora, all of patellae, all of anterior tibiae, and distal portions of posterior tibiae greatly darkened. Palpal femur darkened throughout its length but otherwise unmodified; tip of retrolateral tibial apophysis hooked prolaterally (fig. 103); tegulum expanded, reaching to about one­third of tibial length, embolus hidden in ventral view by sclerotized prolateral rim of conductor (fig. 102). FEMALE: Total length 5.4. Coloration as in male. Epigynum with large, posteriorly situated, heart­shaped atrium (fig. 104); spermathecae tripartite, posterior portions long, narrow (fig. 105). OTHER MATERIAL EXAMINED: The male associated with the holotype was taken in litter at Homevale, 218249S, 1488339E, April 1–7, 1975 (V. Davies, R. Kohout, QMB S25979). DISTRIBUTION: Known only from mid­eastern Queensland (map 7)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on pages 59-60, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

Lampona barrow, new species Figures 98, 99; Map 7 TYPE: Male holotype from Barrow Island, 208489S, 1158269E, Western Australia (Feb. 1997; H. Heatwole), deposited in QMB (S34403). ETYMOLOGY: The specific name is a noun in apposition taken from the type locality. DIAGNOSIS: Males of this species can easily be recognized by their oddly shaped, distally bifid retrolateral tibial apophysis (fig. 99). MALE: Total length 5.5. Holotype badly faded, few details of original coloration preserved. Palpal femur darkened, expanded proximally, retrolateral tibial apophysis bifid, with square subdistal lobe (fig. 99); embolus relatively short, distal edge of tegulum heavily sclerotized (fig. 98). FEMALE: Unknown. OTHER MATERIAL EXAMINED: None. DISTRIBUTION: Known only from Barrow Island, Western Australia (map 7)., Published as part of PLATNICK, NORMAN I., 2000, A Relimitation And Revision Of The Australasian Ground Spider Family Lamponidae (Araneae: Gnaphosoidea), pp. 1-328 in Bulletin of the American Museum of Natural History 2000 (245) on pages 58-59, DOI: 10.1206/0003-0090(2000)2452.0.CO;2, http://zenodo.org/record/5348675

SUMMARY 1. Australia has some of the most venomous fauna in the world. Although humans are not usually perceived as being predators against these animals they are often envenomated, accidentally or otherwise. This has led to the development of antivenoms against some of the potentially lethal venoms. However, further understanding of the mechanism(s) of action of these and other venoms is important, not only for developing new treatment strategies but also in the search for novel research tools. 2. The present review discusses the pharmacology of some of the components found in venoms and outlines the research undertaken on some of Australia's venomous animals, with the exception of snakes. 3. Biogenic amines, peptides and enzymes are common venom components and produce a wide range of effects in envenomated humans. For example, respiratory failure observed after envenomation by the box jellyfish (Chironex fleckeri) and Sydney funnel-web spider (Atrax robustus) is most likely due to potent neurotoxins in the venoms. Stonefish (Synanceja trachynis) and platypus (Ornithorhynchus anatinus) venoms, although not considered lethal, cause severe pain. However, the components responsible for these effects have not been isolated. Venom components, as yet unidentified, may be responsible for the cutaneous necrotic lesions that have been reported after some spider bites (e.g. Lampona cylindrata). Other venoms, such as those of the jumper ant (Myrmecia pilosula) and bull ant (M. pyriformis), may produce only mild skin irritation to the majority of humans but a severe anaphylactic response in sensitized victims. 4. While there has been a renewed interest in toxinology, further research is required to fully elucidate the pharmacological action of many of these venoms.

To the editor, I would like to make some comments on the article by Dr Vetter on idiopathic wounds and spider bites in the November issue of the journal.1 Unfortunately, the mythology of spider bites is not confined to the United States and enjoys considerable publicity across the Pacific in Australia and New Zealand. In Australia, little evidence supports the existence of a spider that causes necrotic ulcers. Loxosceles rufescens has been introduced into a small region in South Australia, but reports of necrotic arachnidism occur in all parts of Australia, and this spider has only been implicated in 2 cases.2 The white-tail spider (Lampona spp) is the spider implicated most commonly in the development of necrotic wounds in Australia; however, only 2 confirmed bite cases are cited in the literature and these patients developed only minor ulcers.3 Other implicated spiders include the black house spider (Badumna insignis) and wolf spiders (family Lycosidae). Sac spiders occur in Australia, but unlike in other parts of the world, they have not been implicated in cases involving necrotic lesions.4 Results of studies of the venoms of Australian spiders are also inconclusive and, if interpreted in the light of clinical evidence, suggest that the venoms of most Australian spiders do not contain clinically significant cytotoxic components.5,6 A recent study showed that compared with the venom of recluse spiders (L rufescens) found in South Australia, the venom of white-tail and black house spiders does not have any sphingomyelinase activity.5 This finding supports the idea that the venoms are not the cause of necrotic ulcers; however, the investigators conclude differently, based on finding sphingomyelinase activity in midgut extractions. Venom research is based on the assumption that these spiders cause necrosis in humans, but scant evidence supports this hypothesis. There are mainly case reports of suspected spider bites or cases where the spider was not caught or correctly identified. Results of larger series of confirmed spider bites do not support the existence of necrotic arachnidism in Australia.7,8,9 In 52 cases of confirmed white-tail (L cylindratalmurina group) spider bites, no necrosis or ulceration developed.9 Despite this, the diagnoses of “white-tail spider bite” and necrotic arachnidism are entrenched in Australian medical culture, and other diagnoses usually are not even entertained. Vetter refers to a case from Australia in which a skin lesion initially identified as a spider bite was eventually found to be caused by a fungal infection, sporotrichosis.10 There are other cases of misdiagnosis of necrotic arachnidism in Australia, including pyoderma gangrenosum,11 Chromobacterium violaceum8 and Mycobacterium ulcerans.12 In my experience, even more common conditions are misdiagnosed, including Herpes zoster, candidiasis, staphylococcal infections, and skin reactions to arthropod bites (usually bullous reactions). Although secondary infections may result from spider bites, this occurrence appears to be uncommon in a series of 371 confirmed spider bites (unpublished data, 2000). I support the author in urging the medical community to investigate necrotic wounds properly and not simply implicate spiders as the cause of ulceration. With no history of spider bite, the diagnosis of necrotic arachnidism should be at the end of a long list of important differential diagnoses of necrotic ulcers. A good history and physical examination may quickly reveal common causes. Investigations should include wound swabs for microbiologic analysis, and for persistent necrotic lesions (over 3 to 4 weeks), a skin biopsy specimen should be sent for histopathologic assessment and appropriate microbiologic cultures (eg, fungal). In most cases, a correct diagnosis will allow the start of appropriate treatment.

Thirty-six cases of bites by spiders are reported; in all cases, the spider was identified. No cases resulted in the formation of local ulcers, in necrosis, or in serious systemic symptoms. Eight bites by Lampona cylindrata, the white-tailed spider, caused a mild sting to sharp pain of short duration, itchiness, erythema, local swelling or a lump, and either no systemic symptoms, or anxiety. Five bites by Badumna insignis, the black house-spider, caused local pain, erythema, swelling, and no systemic symptoms, or anxiety, or chest pain and shortness of breath of mild degree and of short duration. The other spiders to be reported as causing bites were Hadronyche adelaidensis, Misgolas andrewsi, Aganippe subtristis, Olios calligaster, Isopeda pessleri, Eriophora sp., Phonognatha graeffei, Holoplatys sp., Breda jovialis, Opisthoncus sp., Lycosa sp. and Achaearanea tepidariorum.