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You can now earn CPD points with How to Treat by completing quizzes online (www.australiandoctor.com.au/cpd) or in every issue. See page 34 for details and this week’s quiz. INSIDE Definition, clinical features and epidemiology

An approach to the diagnosis of suspected and definite bites

Definite spider bites

Case studies

The author

Dr Geoff Isbister, emergency physician and clinical toxicologist, Newcastle Mater Misericordiae Hospital; clinical pharmacologist, The Children’s Hospital Suspected at Westmead, NSW; clinical toxicologist, NSW and Queensland Poisons Information centres; conjoint senior lecturer, University of Newcastle; and honorary senior spider bite lecturer, Monash Venom Group, Monash University, Melbourne. Definition, clinical features and epidemiology

EACH year thousands of calls about in many reports the spider has not and the conditions that must be met eral public and clinicians often spider bites are made to poisons been caught or identified by an to establish definite spider bite cases. incorrectly identify . information centres around Aus- expert. For a spider bite to be regarded as a Management of patients can be tralia. There has been significant A recent study of 750 definite definite bite by a particular species, based on clinical findings and an misinformation about spiders and spider bites,1 in which the spider was all of the following must be satis- algorithm that does not require the effects of suspected spider bites collected at the time of the bite and fied: spider identification (see later). in Australia, particularly in relation identified by an expert, has improved ■ Evidence of a bite, including clinical When identification is required, to necrotic arachnidism (necrotic our knowledge, and much of the fol- effects such as discomfort or pain spiders can be identified by a local ulcers or skin lesions that occur after lowing review is based on that study at the time or soon after the bite. museum or they can be sent to the With this issue a spider bite). and subgroup analyses of it. ■ Collection of the spider at the time author (see page 31 for contact Information on the clinical effects A discussion of spider bite requires or immediately after the bite. details). a guide to of spider bite is based mainly on case an understanding of what constitutes ■ Identification of the spider by an Pain or discomfort is a universal reports and small cases series, and good evidence in clinical toxicology expert arachnologist. Both the gen- cont’d next page spider bite

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how to treat - suspected spider bite

from previous page Table 1: Medically important and common spiders responsible for definite bites in Australia finding in spider bite and the pro- 1 longed absence of pain is strong evi- (Adapted from: Isbister and Gray, 2002. ) dence against a bite. The characteris- tics of the pain, including duration Common name and important members Spider family % of bites and an initial increase in pain or radi- Huntsman spiders Sparassidae 23 ating pain are often helpful in distin- guishing effects of different spider Orb weavers Araneidae 21 bitess. Other important local effects White-tail spiders, including spp 16 include: ■ Fang marks or bleeding, which Comb-footed spiders, including widow spiders 11 indicate the size of the fangs and (Latrodectus spp) and cupboard spiders (Steatoda spp) of the spider. (Courtesy of Monash Venom Group). Wolf spiders Lycosidae 6 ■ Erythema or red mark, which is variable in size but is found in 60- medically significant bites (44 [6%]), Jumping spiders Salticidae 5 80% of spider bites. most (37) by red-back spiders Black house spiders : spp 3 ■ Itchiness (immediate or delayed). (Latrodectus hasselti). Swelling and oedema are uncom- Table 1 lists the medically impor- Sac spiders, including Cheiracanthium spp Clubionidae 2 mon findings. tant and common families of spi- Mouse spiders : Missulena spp 2 In the study of 750 spider bites ders in Australia. Some of the referred to above, 82% were caused common and important spiders are Funnel-web spiders (Atrax spp and Hadronyche spp) , Atracinae 1 by six major families of spiders. pictured throughout this article. Trapdoor spiders and 2 Most bites caused only minor effects Most bites occurred in the warmer and did not require treatment in a months and occurred between 8am Whistling spiders, or ‘’ Theraphosidae 1 health care facility. Exceptions were and midnight.

An approach to the diagnosis of suspected and definite spider bites

IT is not uncommon for Figure 1: Decision tree for predicting types of spider bites (also available online at australiandoctor.com.au in the How to Treat section of our web site). patients to present with signs and symptoms, including skin lesions or necrotic Yes No ulcers, that they attribute to Bleeding/fang marks BBS = big black spider a spider bite. It is essential RED = red-back spider in these cases that the his- tory of a spider bite be con- OTH = other spider NSW, SA, Vic, Qld, firmed or excluded. If there Tas, NT ACT, WA is no history of a bite, the State/territory Yes No diagnosis and investigation Local diaphoresis must focus on the important causes of necrotic ulcers, including infectious, inflam- Distal Other matory, vascular and neo- BBS RED Bite region plastic aetiologies. An approach to this is outlined Sep-May Jun-Aug in table 2. When there is a history of Month a definite bite, particularly if the spider is collected at the time, any symptoms can be 12pm-4am 4am-12pm attributed to the bite and the Dec-Feb Mar -Nov appropriate management Month Time instigated. The management OTH BBS of definite spider bite requires reliable information RED Qld, WA, Vic, NSW, SA, RED OTH on the effects of spiders in Tas, ACT NT the region where the spider is found. State/territory In Australia, definite spider bites can be divided into bites by three clinically relevant groups: big black spiders, red-back spiders, OTH BBS and all other spiders. Big black spiders include funnel- web spiders, mouse spiders White-tail spider A diagnostic algorithm that bites were incorrectly classi- and other mygalomorphs attacking a black house can distinguish between bites fied (100% sensitivity). It is (large primitive spiders, spider (eating a fly). of big black spiders (includ- hoped that this algorithm including trapdoor spiders). ing funnel-web spiders), red- will improve the identifica- All bites by these spiders back spiders and all other tion of spiders in patients should be treated initially as spiders has been developed presenting to a doctor or suspected funnel-web bites from information collected asking for advice by phone in eastern Australia until no in 789 definite spider bites. after a spider bite. evidence of envenoming is It can be used in any case in In patients with definite or established. which there is a definite his- probable bites when the Although red-back spider tory of a spider bite, whether spider was not collected or envenoming is not a rapidly the person collected the described, the algorithm will developing condition or spider or not, but they need allow the doctor to give likely to be life threatening, to have seen a spider biting. immediate treatment advice recent evidence suggests that spider (and some related detailed information on the The algorithm involves based on the known effects it often causes significant species), they can be reas- management of red-back obtaining information from of that spider group. It pain and other unpleasant sured there will be no major spider or funnel-web enven- six questions (table 3) to should help health care symptoms. effects (table 3). oming is discussed later. determine the spider type workers in diagnosing and The remaining spiders Probable bites by med- Information on early clini- and path through the deci- managing medically signifi- responsible for bites in Aus- ically important spiders cal effects, circumstances of the sion-tree algorithm (figure cant spider bites, but should tralia cause minor effects should be managed accord- bite and geographical distribu- 1). This algorithm accurately not replace good clinical only, so if the person has not ing to their clinical effects. tion of spiders can be used to classified 47 out of 49 big judgment. been bitten by either a big Suggested treatment advice help make the diagnosis of a black spider bites (96%), Unfortunately, the speci- black spider or a red-back is included in table 3. More particular spider bite. and no funnel-web spider ficity of the algorithm means

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that several harmless spiders Table 2: An approach to the investigation and Table 3: Questions for the spider bite diagnostic algorithm, and the recommended are classified as big black treatment advice* spiders. This may be diagnosis of necrotic skin ulcers presenting as Questions improved with further suspected spider bites* ■ Are puncture marks, fang marks or bleeding present at the bite site? research and refinement of Establish whether or not there is a history of spider bite ■ In which state/territory did the bite occur? the algorithm. ■ Clear history of spider bite (better if spider is caught): ■ Is there localised diaphoresis? — Refer to information on definite spider bites Necrotic arachnidism and ■ In which month did the bite occur? ■ No history of spider bite: white-tail spider bite ■ At what time of day did the bite occur? — Investigation should focus on the clinical findings: ulcer or Necrotic arachnidism refers ■ Where is the bite region (distal site or not)? skin lesion to necrotic ulcers or skin Treatment advice lesions that occur after a — Provisional diagnosis of a suspected spider bite is Big black spiders inappropriate spider bite. The condition is ■ The patient should be observed in hospital for four hours and can be discharged if they remain recognised in many parts of Clinical history and examination asymptomatic or have only local effects. Patients at home should be advised to remain immobile, the world but there is only ■ Important considerations: apply a pressure bandage and call an ambulance. good evidence for necrotic — Features suggestive of infection, malignant processes or Red-back spiders arachnidism occurring after vasculitis ■ Patients with a red-back spider bite should be observed and antivenom considered if there are bites by Loxosceles spiders — Underlying disease processes: diabetes, vascular disease severe local or systemic features. Discharged patients should be advised about the effects of red- (‘recluse spiders’). There is — Environmental exposure: soil, chemical, infective back spider bite and to return if they have systemic effects or worsening pain. It is advisable to follow little evidence for the — Prescription medications up patients at 6-12 hours (particularly children). Patients at home should be given information on red- involvement of other spiders — History of minor trauma back spider bite, including the chance of systemic effects and severe persistent pain. They should although many groups of be advised to attend hospital or an ED if they have worsening pain or systemic effects. They do not ■ Specific historical information about the ulcer can assist in spiders continue to be require urgent transport to hospital. differentiating some conditions: blamed for necrotic arachni- Others dism. — Painful of painless ■ Reassure the patient and discharge home. If patient is at home, they do not require medical In Australia, the term — Duration and time of progression attention. necrotic arachnidism arose — Preceding lesion in the early 1980s, with sev- Investigations Note: In cases where the algorithm (figure 1) suggests bites by red-backs (RED) or other spiders eral cases of ulcers being (OTH) but the patient clearly describes a ‘big black spider’, advice should be given as per big ■ Skin biopsy: reported after a suspected black spiders, (ie, this information overrides the conclusion from the algorithm). — Microbiology: contact microbiology laboratory before bite, often after gardening. collecting specimens so that appropriate material and It was suggested that these *Adapted from: Isbister GK, Sibbritt D. Developing a decision tree algorithm for the diagnosis of suspected transport conditions are used for fungi, Mycobacterium ulcers were the result of a spider bites. Emergency Medicine 2004; 16(2):161-66. spp, and unusual bacteria spider bite, and several spi- ders were implicated, includ- — Histopathology There are several published group, a persistent red mark ing white-tail spiders (Lam- ■ Laboratory Investigations: may be important for underlying cases demonstrating misdiag- and associated itchiness, pona spp), wolf spiders conditions (autoimmune conditions, vasculitis), including, but not nosis of necrotic arachnidism, pain or lump that lasted for (family Lycosidae) and, later, be limited, to: failure to diagnose the cor- seven days on average, in the black house spider (Bad- — Biochemistry (including liver and renal function tests) rect underlying condition and 44%. umna spp). — FBC and coagulation studies delay in appropriate treat- Analysis of bites by black After this there were — Autoimmune screening tests, cryoglobulins ment. In the most recent house spiders and wolf spiders 2 reports of several suspected ■ Imaging: study, 11 cases of suspected also confirmed that these spi- cases of white-tail spider bite white-tail spider bite were ders do not cause necrotic — Chest radiography but in none of these was the found to have alternative ulcers. Australian wolf spider — Colonoscopy spider caught or identified, diagnoses, including der- bites cause minor effects (table and often was not even seen — Vascular function studies of lower limbs matophytoses, staphylococ- 4). Bites by the common biting the patient. Treatment cal infections, pyoderma gan- garden wolf spider caused sig- Necrotic arachnidism is ■ Local wound management grenosum, cutaneous nificantly more itchiness and now commonly referred to ■ Treatment based on definite diagnosis or established pathology polyarteritis nodosa, Nocar- redness, and larger wolf spi- in Australia as white-tail ■ Investigation and treatment of underlying conditions may be dia braziliensis infection and ders more often caused severe spider bite and the terminol- important, (eg, pyoderma gangrenosum or diabetes mellitus) an infected diabetic ulcer. pain and left fang marks. ogy is accepted by a large Follow-up and monitoring In a prospective study of Current evidence suggests number of medical practi- 130 white-tail spider bites3 that spider bites are very ■ The diagnosis may take weeks or months to be established, so tioners. The considerable there were no cases of unlikely to cause necrotic patients must have ongoing follow-up. . publicity and general accep- necrotic ulcers. Definite bites lesions and any cases of tance of the condition has ■ Continuing management: co-ordinated with multiple specialities by white-tail spiders caused necrotic ulcers presenting as lead to an increased diagno- involved pain in only one-fifth of suspected spider bites should sis of the condition by med- patients, pain and a red be thoroughly investigated for ical practitioners, despite the *Adapted from: Isbister GK, Whyte IM. Suspected white-tail spider mark lasting less than 24 other causes. Hopefully the bite and necrotic ulcers. Internal Medicine Journal 2004; 34(1-2):38- absence of evidence of a 44. hours in about one-third myth of the white-tail spider spider bite. and, in the most severe will slowly be forgotten.

4 Table 4: Clinical effects of bites by important spider groups ( or family) in Australia (Adapted from: Isbister and White, 2003. )

Clinical effects (%) Latrodectus Steatoda Sparassidae Araneidae Lycosidae Lampona Atracinae (funnel- Missulena (red-back spiders) (cupboard spider) (huntsman) (orb weavers) (wolf spiders) (white-tail spiders) web spiders) (mouse spider) Severe pain 62% 26% 27% 17% 24% 27% 56% 77% Duration of paina 36 hours 6 hours 5 min 5 min 10 min 5 min 120 min 45 min Radiating pain 38% 13% 4% 3% 7% 2% 13% 38% Fang marks/bleeding 6% 17% 54% 32% 33% 19% 81% 54% Redness/red mark 74% 96% 57% 71% 67% 83% (44%)b 31% 38% Itchiness 38% 48% 14% 15% 13%c 44% 0 0 Systemic effectsd 35% 30% 4% 10% 7% 9% 31% (13%)e 38% Circumstances: Indoors 56% 78% 56% 52% 48% 95% 37% 69% Night (6pm-6am) 37% 30% 26% 23% 37% 64% 25% 15% Winter (May-Aug) 12% 26% 17% 8% 17% 5% 25% 23% Typical activity (%) Putting on shoe Dressing Interfering with Washing- — Trapped between Garden- — (28%) (48%) spider (76%) related (41%) material and skin (63%) related (44%) Distal limb bite 46% 52% 82% 34% 72% 25% 81% 92%

aMedian duration of pain. b44% of cases had a persistent red mark with itchiness, pain or a lump for a median of seven days. cItchiness occurred in 33% of bites by the common garden wolf spider. dSystemic effects were mainly nausea, vomiting, headache and malaise. e13% (two cases) had severe neurotoxicity requiring antivenom.

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how to treat - suspected spider bite

Definite spider bites

TABLE 4 (previous page) provides a summary of the clinical administered over 20-30 min- commonly, bites are uncom- effects and circumstances of bites in the medically important Table 5: Clinical effects of red-back spider bites utes) and premedication is not mon and severe envenoming groups of spiders, and the spiders that most commonly cause recommended. However, the rare. bites. The initial management of red-back spider bite and funnel- Local and regional effects antivenom should not be Although only 5-10 severe web bite is included in table 3 (previous page). More severe cases ■ Local pain: increasing pain at the bite site over a period of administered undiluted or envenomings require anti- require antivenom and should be referred to an emergency minutes to hours. The pain may last for well over 24 hours rapidly because this may cause venom in Australia annually, department for ongoing management. ■ Radiating pain: from the bite site to the proximal limb, trunk or complement-mediated reac- it remains an important clini- local lymph nodes tions. cal condition because of its Red-back spider bites ■ Local sweating Serum sickness after 4-15 rapid onset, life-threatening Red-back spider bites cause a clinical syndrome often referred to ■ Regional sweating: unusual distributions of diaphoresis, usually days, characterised by fever, effects and the availability of as latrodectism, which is responsible for significant morbidity associated with the site of the bite rash, arthralgia, myalgia and effective antivenom. in Australia. It has been estimated that there are at least 5000 red- ■ Piloerection non-specific systemic features, Local effects of funnel-web back spider bites annually in Australia, but there is significant geo- ■ Local erythema is uncommon, but patients spider bites include puncture graphical variation, with far more bites in the temperate regions of should be warned of this marks and local bleeding. Australia, and far fewer in the colder south or tropical north. Systemic effects adverse effect. A short course Local pain is often severe and Retrospective studies appear to have underestimated the sever- ■ Remote or generalised pain or generalised myalgia of oral corticosteroids is indi- may last for 1-4 hours. Red- ity of cases and, importantly, the frequency and duration of cated in moderate-to-severe ness and swelling are less ■ Abdominal pain (differential diagnosis: acute abdomen) severe pain. A recent prospective study of 68 red-back spider cases of serum sickness. common. When these are the ■ Nausea, vomiting and headache bites, in which all cases were followed up, showed severe and per- Antivenom has been safely only reactions, the condition ■ Malaise and lethargy sistent pain in two-thirds of cases, severe enough to prevent the administered in pregnancy and is often referred to as a dry patient sleeping in almost one-third of all cases (table 4).5 This ■ Hypertension during breastfeeding. Patients bite. Severe envenoming devel- study also suggested that more patients should receive treatment ■ Irritability and agitation* can be safely discharged after ops in only a proportion of (antivenom) on the basis of pain alone and not just systemic ■ Fever there is resolution of the clini- cases and is characterised by: effects. ■ Paraesthesia cal effects two hours after ■ Massive autonomic stimula- Red-back spiders tend to occur in dry and dark places, and the ■ Chest pain (differential diagnosis: acute MI) antivenom therapy, and tion/excitation (both sympa- circumstances of the bite may be useful for making the diagnosis. ■ Muscle spasms admission for further treat- thetic and parasympathetic) A common way to be bitten is by putting on a shoe with the ■ Patchy paralysis ment is rarely required. with generalised diaphoresis, spider in it. These spiders are also found under outdoor furniture, There are case reports of the hypersalivation, lacrimation, in bike helmets and pot plants, and occasionally in clothes or *More common in children successful administration of piloerection, hypertension, shoes left lying around. red-back spider antivenom bradycardia or tachycardia, The appearance of the spider means that most people are able days to weeks after the bite. and miosis or mydriasis. to identify it, but in a proportion of cases the spider is not seen at The use of antivenom in the ■ Neuromuscular excitation: the time of the bite. Bites are far more common from the larger period 24-96 hours after the paraesthesia (local, distal and female spiders, although bites by juvenile spiders also occur. bite appears justified based on oral), fasciculations (local or In the prospective study5 there was no difference between the the natural course of the generalised, commonly effects of female and juvenile spiders. The male red-back spider is envenoming and the frequent tongue fasciculations) and much smaller and rarely responsible for bites, although two cases response in these cases. muscle spasms. have been reported. ■ Non-specific systemic effects: Red-back spider bites can occur throughout the year but are Steatoda species: nausea, vomiting, abdominal most common between January and April. They are charac- cupboard, or button, pain and headache. terised by pain (localised, radiating and regional) associated with spiders ■ Non-cardiogenic pulmonary non-specific systemic features, local and regional diaphoresis Steatoda spiders belong to the oedema and, less commonly, and, less commonly, other autonomic and neurological effects same family as red-back spi- myocardial injury. (tables 4 and 5). ders. In a recent study the clin- ■ Central nervous effects: agi- The pattern of the pain is characteristic, increasing over the first Red-back spider. ical effects of Steatoda spider tation/anxiety, drowsiness hour in more than half of cases. It may radiate proximally (from bite were similar to, but less and coma (CNS depression a distal limb bite) and less commonly to the trunk. The bite may severe than, those of red-back appears to be more common only cause an initial irritation or discomfort, which may be the spider bites.6 in children). reason the spider is not seen in some cases. Bites by these spiders may Other effects, including neu- Red-back spiders are small and rarely leave puncture marks or cause prolonged and radiating romuscular paralysis, cause bleeding at the bite site. Erythema is the most common find- pain and non-specific systemic intractable hypotension, sec- ing at the bite site and local diaphoresis occurs in about one-third effects (table 4). In the most ondary coagulopathy and of cases. Swelling is uncommon. severe cases the effects are multi-organ failure, were Systemic effects (listed in table 5) include nausea, vomiting, almost indistinguishable from reported before the introduc- lethargy, malaise and headache. Hypertension, generalised myal- those of red-back spider bite, tion of antivenom. gia and muscle spasms are often reported in the literature but are except for the absence of local In a proportion of cases less less common in large series of cases. and regional diaphoresis. severe envenoming occurs, The effects of envenoming usually lasts about 1-4 days and in Some bites that are consistent with local neurotoxicity the prospective study5 almost all cases completely resolved within with red-back spider bites but (paraesthesia, numbness or one week. No deaths have been reported since the mid-1950s. for which no spider has been fasciculations), non-specific The diagnosis, particularly if a spider is not seen, is clinical, and collected may be severe cases systemic effects or limited sys- a combination of the circumstances of the bite, the character of of Steatoda bites. temic envenoming. the pain, and local or regional diaphoresis is often enough to Symptomatic treatment is Severe envenoming has been make this diagnosis. However, in children and especially in Funnel-web spider. still to use IM antivenom. the mainstay of treatment in reported in bites from only six infants, the diagnosis may be more difficult. Infants may simply If adult patients with defi- Steatoda bites. In severe cases, species of funnel-web confined present with irritability and distress. nite red-back spider bites do IV red-back spider antivenom to NSW and southern The treatment of red-back spider bite varies considerably based not respond to two ampoules may be considered based on Queensland, including the on the perceived severity of most bites and concerns about the of IM antivenom or they have reports of its use in Steatoda Sydney funnel-web (Atrax effectiveness and safety of antivenom. The recent prospective severe systemic effects, IV bites and in vitro studies. robustus), the southern tree study in Australia suggests antivenom should be considered in up administration should be con- Spider bites from the genus funnel-web (Hadronyche cer- to two-thirds of cases.5 sidered first line. It is impor- Achaearanea (also from the berea) and northern tree When a patient has systemic effects and severe or persistent tant that this diversion from same family as red-back spi- funnel-web (Hadronyche for- local pain, it is reasonable to explain that the pain may persist for the recommended route is dis- ders), cause prolonged pain midabilis). Only local effects 24-96 hours and allow the patient to choose whether to have cussed with the patient. similar to that of red-back spi- and less severe envenoming antivenom. Local analgesia may be effective in the most minor Because red-back spider ders, but no systemic effects have been reported for most cases but in most cases oral and even parenteral opiates have been bites are likely to be more occur. other species. ineffective. severe in children (based on a An important part of the Patients who require no treatment can be discharged but should similar dose of venom being Funnel-web spider bites management of funnel-web be given clear instructions to return if the pain increases, systemic injected into a smaller body Funnel-web spiders (Hexathe- spider bite is initial first aid effects occur or they are unable to tolerate persistent pain. mass) it is appropriate to con- lidae, Atracinae families: Atrax and transport of the patient to Because of the slow development of the effects of envenoming sider IV antivenom as first line and Hadronyche spp) are the an emergency department or (often 4-12 hours) it is unnecessary to observe these patients. If treatment for red-back enven- most dangerous spiders in local hospital. The mainstay children are discharged home without treatment it is prudent to oming in children. Australia. Although they occur of treatment in hospital is contact the parents or carers after 6-12 hours, as well as giving It is reasonable to discuss widely throughout eastern funnel-web spider antivenom, them instructions to return if the child’s condition becomes worse. the use of IV antivenom with a Australia, severe envenoming admission to a critical care There is increasing evidence that intramuscular antivenom is clinical toxicologist. Early has only been reported from area and monitoring for 12- less effective than previously believed, and controlled studies are allergic reactions are rare southern Queensland to south- 24 hours until all evidence of being undertaken to determine whether IV antivenom is more (<1%) when it is administered ern NSW. Even in parts of envenoming has resolved. effective. However, the recommendation of the manufacturer is intravenously (diluted and NSW where the spiders occur Atropine may be used for con-

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References 1. Isbister GK, Gray MR. A trol of excessive secretions. Details for expert spider identification minor effects from leg spines prospective study of 750 Funnel-web spider anti- and contact allergic reactions definite spider bites, with venom is a rabbit-derived IgG To obtain expert identification of a spider that has bitten a patient, send the spider in a specimen of the skin and eye. Injuries expert spider identification. antivenom that appears to collection jar (in a small amount of 70-100% ethanol) with a short summary of the clinical details, from the front leg spines cause Queensland Journal of Med- reverse envenoming effectively and your contact details, to: pain at the time of contact icine 2002; 95:723-31. after bites from Atrax and Dr Geoff Isbister, with the spider, often mistaken 2. Isbister GK, Whyte IM. Hadronyche spp. Premedica- Newcastle Mater Hospital for a bite, but distinguished Suspected white-tail spider Edith St, Waratah, tion is not recommended and from bites by the presence of bite and necrotic ulcers. NSW 2298 early allergic reactions and ‘splinters’ at the bite site. Internal Medicine Journal serum sickness are rare. *Obtain permission from the patient for unidentified clinical details to be provided to Dr Isbister In some cases this can lead 2004; 34(1-2):38-44. The initial dose of to local inflammation that 3. Isbister GK, Gray MR. antivenom should be two may persist for several days. White-tail spider-bite: A ampoules (250 units) intra- Summary — suspected and definite spider bite Hairs of South American ther- prospective study of 130 venously, which can be ■ In cases of suspected spider bite, the history of a bite should be confirmed and should only be con- aphosid spiders (tarantulas) definite bites by Lampona repeated until the features of sidered a definite bite if a spider was seen and there are immediate clinical effects. can cause urticarial skin reac- species. Medical Journal of envenoming have resolved. ■ Most spider bites cause minimal or no effects, including bites by huntsman spiders, orb-weaving spi- tions and ocular injuries. This Australia 2003; 179(4):199- Patients bitten by funnel- ders, wolf spiders, black house spiders and white-tail spiders. may become an increasing 202. web spiders without symp- ■ Significant morbidity is restricted to a few groups, including red-back spiders (and related spiders) problem in Australia, with 4. Isbister GK, White J. toms of severe envenoming, or and funnel-web spiders in Australia. these creatures becoming pop- Clinical consequences of bites by unidentified big black ■ Necrotic ulcers are highly unlikely to result from spider bites, and comprehensive investigation is ular pets. spider bites: recent advances spiders in eastern Australia, required to identify the cause in suspected cases presenting with skin lesions or ulcers. Conjunctival inflammation in our understanding. Toxi- should initially be treated as ■ The initial clinical effects and circumstances of spider bites can help with rapid discrimination of from the contents of con 2003; 43(5):477-92. suspected funnel-web spider potentially medically important spider bites. squashed spiders entering the 5. Isbister GK, Gray MR. envenoming. ■ A diagnostic algorithm can be used to discriminate big black spiders (including funnel-web spiders), eye has been reported. This Latrodectism: a prospective The patient should have a red-back spiders and all other spiders. can be from either small spi- cohort study of bites by for- pressure immobilisation band- ■ Suspected funnel-web spider bites should be observed and managed in hospital. ders, such as daddy-long-legs, mally identified red back age applied, be transported ■ Patients with red-back spider bites should be warned that prolonged pain may occur. In a significant being rubbed in the eyes, or spiders. MJA 2003; rapidly to hospital and proportion of cases, antivenom should be considered. large spiders being hit with 179(2):88-91. observed in an emergency ■ For medical advice on envenoming contact the Poisons Information Centre (13 11 26). objects and the contents of 6. Isbister GK, Gray MR. department for 2-4 hours. The the spider being projected Effects of envenoming by pressure immobilisation ban- into the eye. comb-footed spiders of the Eastern mouse spider dage can be removed when the (Courtesy of Monash This causes transient but genera Steatoda and antivenom is available. Venom Group). severe conjunctival inflamma- Achaearanea (family If there is no evidence of tion characterised by redness, Theridiidae: Araneae) in severe envenoming after two oedema and significant pain. Australia. Journal of Toxi- hours, it is unlikely to occur, Treatment is by irrigation of cology. Clinical Toxicology but it is prudent to observe the the eye and analgesia. The 2003; 41(6):809-19. patient for four hours in total. effects resolve within 24 hours. 7. Isbister GK. Mouse spider bites (Missulena spp.) and Mouse spider bites Spider bites in children their medical importance: a Mouse spiders (Missulena spp) Although a subgroup analysis systematic review. MJA are similar in appearance to of the study demonstrated that 2004; 180(5):225-27. funnel-web spiders and occur most effects of spider bites in 8. Isbister GK. A prospec- throughout mainland Aus- children are minor compared tive cohort study of definite tralia. Suspected mouse spider with those seen in adults, the spider bites in Australian bites should be treated as Garden orb-weaving spider, analysis did not include children. Journal of Paedi- funnel-web spider bites in east- one of the most common enough cases of red-back or atrics and Child Health ern Australia because these causes of spider bites in funnel-web spider bites to con- 2004; 40:360-364. spiders are easily mistaken for Australia. firm or deny this conclusion 9. Trethewy CE, Bolisetty S, funnel-web spiders. in these groups of spiders.8 Wheaton G. Red-back A systematic review of Theoretically red-back and spider envenomation in chil- mouse spider bites found that funnel-web spider envenoming dren in Central Australia. severe envenoming from these will be more severe in children Emergency Medicine 2003; spiders was rare, with only one because they are exposed to 15:170-75. case out of 40 definite mouse the same injected dose of spider bites.7 Mouse spider venom as adults, so the dose Online resources bites cause mainly local effects per body weight is higher in Clinical toxinology network (pain and fang marks), but children. It is therefore appro- web site: local neurotoxic effects priate to assume that red-back www.toxinology.net (paraesthesia) and non-specific spiders may cause significant ‘Toxinz’ poisons systemic effects occur in some effects in children. management database: cases. This conclusion is consistent www.toxinz.com with recent research in chil- Other common spiders that effects of bites between differ- dren that showed that systemic cause minimal effects ent species of huntsman and severe effects occurred in Huntsman spiders spiders. las) are the largest of the myga- funnel-webs and some species 85% of children, 65% having Huntsman spiders (family lomorph spiders. They occur have a similar distribution to all three signs of diaphoresis, Sparassidae) are large spiders Orb-weaving spiders in all parts of the world and that of funnel-webs. hypertension and irritability,9 that are often feared by people Orb-weaving spiders, which are being increasingly kept as The Sydney brown trapdoor in contrast with only 22% in because of their size and ability belong to the family Aranei- pets. Bites from these spiders, spider (Misgolas rapax) is earlier research. to climb walls. They are the dae, cause a significant although potentially lethal to often confused with the However both studies were most common spider to cause number of bites, but most are some domestic , appear Sydney funnel-web spider. retrospective and only bites in Australia but only from garden orb weavers to cause little effect in humans, Although the circumstances included patients admitted to cause minor effects consistent (Eriophora spp). Bites by these based on a series of bites by (outdoors and gardening) and hospital, with widely varying with the mechanical effects of nocturnal spiders often occur Australian theraphosids initial local effects (distal rates of antivenom use. The their large fangs (table 4). when clothes dried on the (Whistling spiders). painful bites, often with fang dose of antivenom for red- Most bites, which com- washing line, typically Local pain was the most marks) are similar to those of back spider bites (and funnel- monly follow interference with overnight, are put on. common effect, usually asso- funnel-web bites, trapdoor web spider envenoming) is the the spider, occur on distal Bites cause minor effects, ciated with puncture marks spider bites cause only minor same in children as adults limbs and cause immediate including transient pain, asso- and bleeding. Bites in dogs effects and should be managed because it based on the dose and transient pain and punc- ciated with localised redness. were far more severe, with as funnel-web bites until there of venom injected by the ture marks or bleeding in more Bites from banded orb death occurring in all seven is no evidence of envenoming spider and not the weight of than half of cases. Systemic weavers and golden orb reported cases. after 2-4 hours. the child. effects are rare. Features con- weavers are rare in Australia A clinical toxicologist can sistent with local infection are but appear to cause only Trapdoor spiders Spider injuries be contacted for advice on reported more commonly minor effects. Trapdoor spiders occur other than bites severe envenoming through (2.3% of cases) than with any throughout Australia. Those In addition to bites, injuries the Poisons Information other group of spiders. There Tarantulas from the family Idiopidae are have been reported from con- Centre (13 11 26) 24 hours a are no major differences in Theraphosid spiders (Tarantu- similar in appearance to tact with spiders, including day.

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how to treat - suspected spider bite

Author’s case studies

Increasing and persistent pain Questions 3. After the failure of two ampoules his index finger and complains of immobilise the child and apply a after putting on shoes 1. What is the most likely diagnosis? of IM antivenom, IV antivenom pain in his hand. firm bandage to the hand and arm A 46-YEAR-old man presents 2. What is the appropriate treatment should be seriously considered in with a 10-15cm crepe bandage. She with pain in his right leg and for this man? a patient with significant ongoing Questions should call for an ambulance for abdomen. He says the pain started 3. In the emergency department he is symptoms. This can be discussed 1. What is the appropriate advice for immediate transport to hospital. about 15-30 minutes after he put administered two ampoules of with a clinical toxicologist and this mother? 2. Features of funnel-web spider his shoes on this morning (seven antivenom IM two hours apart, but the patient. Antivenom should be 2. What symptoms and signs would envenoming, including autonomic hours ago). has ongoing pain and has devel- administered diluted in about you look for in the child once they features (diaphoresis, salivation, Initially he had increasing pain oped malaise. What further man- 200mL of normal saline over 20- arrive in hospital? lacrymation, miosis or mydriasis), in his right toe, which radiated agement should be considered? 30 minutes. 3. In a child with dyspnoea, gener- neuro-excitation (paraesthesia, fas- to his knee and groin. He is now alised diaphoresis, drowsiness and ciculations and muscle spasm), pul- in considerable distress from the Answers Identified big black spider bite hypertension, what is the appro- monary oedema, hypertension and pain. On examination there is no 1. Red-back spider bite. You are called by a distressed mother priate treatment? drowsiness or irritability. obvious mark on his foot. He 2. Referral to the local hospital or who has found her three-year-old son 3. Antivenom (two ampoules IV) and has bilateral below-knee dia- emergency department for anti- crying with a black spider in his hand. Answers admission or retrieval to a critical phoresis. venom. He has bleeding puncture marks on 1. The mother should be advised to care area.

GP’s contribution

Case study Initially our staff seemed to only one registrar present in of funnel-web antivenom. I Pulmonary oedema occurs IN the summer of 1981 I was doubt it was a significant the hospital at night. It was think he needed either one or in about 40-70% of severe a senior resident in the casu- funnel-web bite because the a rotation of medical, surgi- two further doses, but was funnel-web spider envenom- alty department of Ryde Hos- patient looked well. We asked cal, orthopaedic and anaes- able to walk out of Royal ings, and is more common in pital in Sydney, on an evening him to sit up on the bed in the thetics registrars. The patient North Shore within 48 hours. children. shift, when a middle-aged man emergency room, which he who had been bitten by the walked — or rather limped — did, but almost immediately funnel-web was fortunate Questions for the author How much time usually DR MARICA MANNING, in, saying he’d just been bitten he became severely unwell. He that night because the anaes- Can you cite the statistics on elapses before signs of enven- GREENWICH, NSW by a funnel-web spider. vomited the huge meal he’d thetics registrar was on duty. the use on funnel-web omation appear, and how He’d been changing a light recently consumed, started It was a difficult intubation antivenom around Sydney in effective is the pressure ban- globe in his lounge room and sweating profusely and began but it was achieved and the recent years. dage? had stepped down onto the coughing up white foam. He patient given alcuronium, There are 1-10 cases Signs of envenoming will spider. He had cried out to his had a huge tachycardia and a valium, lasix and some nar- (median, 5) of funnel-web develop within two hours, neighbour, who came quickly systolic blood pressure of cotic. spider bites requiring anti- and usually within the first and applied a pressure ban- more than 200mmHg. Within I was given the task of venom annually, and 0-3 of 30 minutes. Pressure immo- dage to his foot and lower leg. a few minutes of arriving he hand-ventilating him in the these in the Sydney region. bilisation appears to slow It took a few minutes for the appeared to be drowning in ambulance taking him to envenoming (based on case neighbour to drive him up to his own secretions. His ban- Syndey’s Royal North Shore Is the appearance of pul- reports and studies) the hospital. The spider was dage was left undisturbed. Hospital, where he was able monary oedema usual after and so is the recommended not caught. In those days, Ryde had to receive the first ever dose these bites? first aid.

Australian Doctor How To Treat CPD

5. Craig attends the hospital two hours later c) Rapid transport to hospital for observation is Instructions with severe pain, headache and malaise. He necessary ...... ❏ Earn 2 CPD points by completing this quiz online or on the attached card. Mark your is given one ampoule of red-back spider d) Funnel-web spider antivenom should be answers on the card and drop in the post (no stamp required) or fax to (02) 9422 2844. antivenom IM, with resolution of his administered IV on arrival at hospital ...... ❏ For immediate feedback click the ‘Earn CPD pts’ link at www.australiandoctor.com.au symptoms. Which TWO statements about Note that some questions have more than one correct answer. The mark required for CPD red-back spider antivenom are correct? 8. Concerning the consequences of funnel- points is 80%. Your CPD activity will be updated on your RACGP records every January, a) The dose for children is the same as for web spider bite, which ONE statement is April, July and October. adults ...... ❏ incorrect? b) Serum sickness may occur ...... ❏ a) Tongue fasciculation may occur ...... ❏ c) The red-back spider antivenom can only be b) The pain usually lasts for 24 hours ...... ❏ 1. Which symptom/sign is always present attends your surgery, with the spider. What used IM, as per the manufacturer's c) Anxiety and drowsiness may occur . . . . .❏ with a spider bite (choose ONE)? advice would you be most likely to give him recommendation ...... ❏ d) Generalised diaphoresis often occurs . . .❏ a) Fang marks ...... ❏ (choose TWO)? d) Antivenom is unsafe in pregnancy and b) Erythema ...... ❏ a) Craig can be managed at home with breastfeeding ...... ❏ 9. In the emergency department Bob c) Pain or discomfort at the bite site ...... ❏ instructions to attend the hospital if pain develops hypertension, tachycardia, d) Swelling and oedema ...... ❏ increases or if he develops systemic side 6. Carol presents with a necrotic ulcer on hypersalivation and paraesthesia adjacent to effects ...... ❏ her lower leg. Which is the least likely cause the bite. Which ONE statement concerning 2. When a person has seen a spider biting b) Red-back spider antivenom should be of the ulcer? his management is correct? but was unable to collect or describe it, administered IM immediately at the closest a) Cutaneous neoplasia ...... ❏ a) Funnel-web spider antivenom should be which ONE question is least likely to be hospital ...... ❏ b) White-tail spider bite ...... ❏ given once only, IV ...... ❏ helpful in evaluating the significance of the c) Analgesia is very effective in red-back spider c) Peripheral arterial disease/vasculitis . . . . .❏ b) Premedication is necessary before bite? bites ...... ❏ d) Infection ...... ❏ administration of funnel-web spider antivenom a) Is there local diaphoresis? ...... ❏ d) Craig should be advised that the pain may because allergic reactions are common . . . .❏ b) When did the bite occur (month of year, time last 1-4 days ...... ❏ 7. Bob, who lives in NSW, has been bitten c) Serum sickness commonly occurs after of day)? ...... ❏ on the lower leg by a large black spider, administration of funnel-web spider antivenom c) In which state/territory did the bite 4. If Craig had not retrieved the spider, what which he flicked off when he felt the pain. d) Atropine may be warranted in Craig's occur? ...... ❏ THREE clinical features would alert you that There are fang marks. He phones you for management ...... ❏ d) Is there blanching of the skin adjacent to the this is a possible red-back spider bite? advice. Which advice is correct (choose spider bite? ...... ❏ a) The presence of bleeding at the site of the TWO)? 10. Which ONE of the following spider bites bite ...... ❏ a) Bob should remain as immobile as possible is most likely to cause significant effects? 3. Craig, 55, felt a bite and pain while putting b) The character of the pain ...... ❏ until transported to hospital ...... ❏ a) Tarantulas (Theraphosid spiders) ...... ❏ on his gardening gloves and retrieved a red- c) The circumstances of the bite ...... ❏ b) A pressure immobilisation bandage should b) Mouse spiders ...... ❏ back spider. He has local pain, but is not d) The presence of local or regional be applied and immediately removed on arrival c) Huntsman spiders ...... ❏ distressed and has no other signs. He diaphoresis ...... ❏ at hospital ...... ❏ d) Orb-weaving spiders ...... ❏

HOW TO TREAT NEXT WEEK Editor: Dr Lynn Buglar The next How to Treat discusses various aspects of palliative care. The author, Professor Linda Kristjanson, is The Cancer Council of WA professor Co-ordinator: Julian McAllan of palliative care, school of nursing and public health, Edith Cowan University, Churchlands, WA.

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Figure 1: Decision tree for predicting types of spider bites (also available online at australiandoctor.com.au in the How to Treat section of our web site).

Yes No Bleeding/fang marks BBS = big black spider RED = red-back spider

NSW, SA, Vic, Qld, OTH = other spider Tas, NT ACT, WA State/territory Yes No Local diaphoresis

Other BBS Distal RED Bite region

Sep-May Jun-Aug Month

12pm-4am 4am-12pm Dec-Feb Mar -Nov Month Time OTH BBS

RED Qld, WA, Vic, NSW, SA, RED OTH Tas, ACT NT State/territory

OTH BBS

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