TOXICOLOGY/CASE REPORT

Case Report: Compartment Syndrome After a Suspected BlackWidow Spider Bite

Jennifer Cohen, MD

Sean Bush, MD

From the Department of Emergency Medicine, Loma Linda University Medical Center(Cohen, Bush), Loma Linda University School of Medicine, and Children’s Hospital (Bush),Loma Linda, CA.

Widow spider envenomations generally produce systemic neurologic syndromes without significantlocal injury. We report a patient who sustained a black widow spider bite to the left forearm andpresented to the emergency department with rhabdomyolysis and compartment syndrome. Wedocumented a decrease in symptoms and compartment pressure after administration of antivenom.No surgical intervention was performed. We believe this report to be the first documenting compartmentsyndrome associated with black widow spider bite. [Ann Emerg Med. 2005;45:414-416.]

0196-0644/$-see front matterCopyright ª 2005 by the American College of Emergency Physicians.doi:10.1016/j.annemergmed.2004.06.018

INTRODUCTIONAcute compartment syndrome can be limb threatening and

possibly life threatening without treatment. In most cases,primary treatment involves emergency surgical fasciotomy todecompress the compartments.1 Fasciotomy may not beappropriate for compartment syndrome caused by envenoma-tion. There are reported cases of snakebite envenomation thathave been successfully treated with antivenom, with or withoutother noninvasive medical measures, as opposed to immediatesurgical intervention.2,3 We describe the first reported case ofcompartment syndrome associated with a black widow spiderbite. In this case, symptoms improved after antivenom,precluding fasciotomy.

CASE REPORTA 55-year-old, left-hand-dominant man presented to the

emergency department for evaluation of a swollen, painful leftforearm. He stated that at 12:45 PM that afternoon he had beensitting outside when his friend told him there was a spider onhis left arm. He brushed the spider off his arm and crushed it.He did not feel a bite and developed no immediate symptoms.He described a spider with a large, shiny, black abdomen witha red-orange hourglass marking. The only spider native to thearea with this appearance is the western black widow,Latrodectus hesperus (Rick Vetter, MS, personal communication,June 2004). Approximately 45 minutes later, he began havingcramping pain in his left forearm, which gradually worsened,and swelling began to develop. The patient washed his arm withsoap and water but did not perform any home remedies such astourniquet application. He did not crush, injure, or fall asleepon the arm. He did not use any medications, alcohol, or illicit

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drugs. He presented to the emergency department at 3:30 PM

complaining of severe, cramping pain throughout his entire leftarm from the posterior shoulder down to the hand. He hadparesthesias from the forearm up into the shoulder and downinto the fingertips. He was unable to move his fingers or wristbecause of pain but was able to move his shoulder withoutdifficulty. He denied chest pain, shortness of breath, abdominalpain, back pain, or headache. He had one episode of vomiting atapproximately 3 PM. The patient was a truck driver witha medical history of hypertension, and his medications includednifedipine and cephalexin (prescribed by an outside physicianfor an upper respiratory tract infection). He had been takingthese medications for an unknown duration.

His vital signs were blood pressure 141/96 mm Hg, pulserate 83 beats/min, respiratory rate 16 breaths/min, temperature36.2 �C (97.1 �F), and oxygen saturation 98%. The leftproximal forearm was markedly swollen, worse on the volaraspect than the dorsal. The swelling did not extend up into theshoulder or into the hand. There was no visible bite, targetlesion, or puncture wound, so it was impossible to identifyexactly where the bite had occurred. The forearm wasexquisitely tender to palpation, and the compartments weretense. There was no surrounding erythema, induration, orfluctuance suggestive of cellulitis or abscess. He had pain withpassive stretch of the muscles. There was clear venousengorgement of the extremity. He had no diaphoresis and noevidence of Latrodectus facies (grimace, blepharoconjunctivitis,and masseter trismus4). The remainder of his examination wasunremarkable.

The patient’s laboratory studies included normal CBCcount, chemistry panel remarkable for blood urea nitrogen levelof 15 mg/dL (normal range 7 to 20 mg/dL), creatinine level of

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Cohen & Bush Compartment Syndrome and Black Widow Spider Bite

1.9 mg/dL (normal range 0.6 to 1.2 mg/dL), and serum creatinekinase level of 999 IU/L before insertion of the pressuremonitor needle (normal range 32 to 267 IU/L). His urinalysisresult was negative. His erythrocyte sedimentation rate was 2mm/h (normal range for men\10 mm/h). Compartmentpressures in the left forearm were measured with a standard 22-gauge, 3.5-inch pressure monitor needle (Stryker Instruments,Kalamazoo, MI) twice in the volar compartment and found tobe 66 and 54 mm Hg (normal range 0 to 8 mm Hg). The dorsalcompartment pressure was measured at 24 mm Hg. The patientwas given morphine during this period of evaluation, withpartial pain relief.

Because compartment syndrome had developed, the bite wasdetermined to be limb threatening, and the patient was offeredantivenom. Informed consent was obtained, and the antivenominfusion was started at approximately 6:30 PM. The patient waspretreated with 50 mg of diphenhydramine intravenously and300 mg of cimetidine intravenously to prevent allergic reaction.One vial of Antivenin (Latrodectus mactans) was reconstitutedand further diluted to 200 mL in normal saline solution. Themixture was infused at 1 mL/min for the first 10 minutes andthen increased to 200 mL/h. The infusion finished atapproximately 8:30 PM without incident. The patient’ssymptoms had markedly improved. The swelling and pain hadsubjectively decreased, and he was able to move his fingers andwrist. Repeated measurements of compartment pressures wereperformed close to, but not directly in, the puncture holes fromthe original measurements and yielded measurements of 32 mmHg for the volar compartment and 21 mm Hg for the dorsalcompartment. The hand surgery team was consulted andconcluded that a fasciotomy was not indicated. The patient wasgiven a tetanus booster and a dose of cefazolin (ordered by theadmitting team for wound prophylaxis).

During the next 3 days, the patient’s symptoms continued toimprove. Further studies included a left forearm ultrasono-graph, which showed no venous thrombosis, and a left forearmmagnetic resonance imaging study, which demonstrateda lobulated area of heterogenous signal abnormality mainlyinvolving flexor digitorum superficialis. There was a focal5.4�2.5�2.2-cm lesion in the flexor compartment consistentwith hemorrhage, and a large amount of fluid along the ulnarproximal aspect of the forearm consistent with fasciitis. Therewas no evidence of abscess or bony involvement. Theradiologist’s interpretation was consistent with myositis orcompartment syndrome.

Further laboratory studies included a urine drug screen doneon hospital day 2, which was positive only for opiates (after thepatient had been given morphine). The patient’s rhabdomyol-ysis was treated with intravenous fluids (approximately 7 Ltotal). His creatine kinase level decreased to 352 IU/L onhospital day 3 (peak value was 999 IU/L approximately 6 hoursafter the bite). His serum creatinine level increased to 2.1 mg/dL on hospital day 2 but improved thereafter. His CBC countremained normal. The patient was discharged in stablecondition on hospital day 3, with minimal pain and swelling

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and good range of motion of his arm. At 2-week telephonefollow-up, the patient reported that his left upper extremityfunction was back to baseline levels.

DISCUSSIONMore than 40,000 black widow spider bites have been

reported to poison centers in the United States during the past20 years. The female of the species is easily recognizable, witha large, shiny, black abdomen and a red hourglass marking onthe underside. In contrast to many other venomous spiders, thevenom of the widow spiders is primarily a neurotoxin and doesnot usually cause a significant local reaction.5 The bite itself maybe painful but is commonly unnoticed.5-7 Usually, the onlylocal reaction is a small puncture wound or papule, sometimessurrounded by erythema, induration, or a ‘‘target lesion,’’ but itmay also be subtle.5,8 Some cases do not progress from theminimal local reaction or pain, but in others, severeneuromuscular symptoms develop during the first 30 to 60minutes after the bite. There is one reported case of fulminant,fatal myocarditis after a Latrodectus envenomation.9

In our patient, compartment syndrome developed aftera suspected black widow spider bite and improved withantivenom and without surgical intervention. The mechanismof the development of compartment syndrome after widowspider envenomation is unclear. Rhabdomyolysis has beenreported as a rare complication of widow spider bites,10 andrhabdomyolysis is a known cause of compartment syndrome.1

This patient had evidence of rhabdomyolysis, includingincreased creatine kinase and creatinine levels. Conversely, theincreased pressure from a compartment syndrome may causerhabdomyolysis rather than result from it.11 Additionally,there are reports of priapism from widow spider bites thatimplicate direct venom action on blood vessels, leading tovenous engorgement of the penis.12 This patient showedsignificant venous engorgement of his forearm; therefore,venom effect on blood vessels causing obstructed venousoutflow as the precipitant of the compartment syndrome isanother possibility.

Our patient had no clear explanation for developingcompartment syndrome other than the spider bite andimproved rapidly with the administration of antivenom. Thepatient’s symptoms, physical examination results, and di-agnostic and imaging study results were inconsistent with anyalternative diagnosis.

Antivenin (L mactans) has risks, including anaphylaxis andserum sickness, and there is one reported fatality attributed to itsadministration.13 Hence, antivenom is generally consideredonly for envenomations that cause intractable pain refractory totreatment with opioid analgesia and benzodiazepines or forpotentially life-threatening symptoms induced by the enveno-mation, such as uncontrolled hypertensive emergencies orpremature labor.8,14,15 In our case, the compartment syndromewas considered to be limb threatening, thereby meriting the useof antivenom.

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Compartment Syndrome and Black Widow Spider Bite Cohen & Bush

In conclusion, although neuromuscular symptoms remainthe most common manifestation of latrodectism, compartmentsyndrome may also occur. Early recognition of this developmentallows a trial of antivenom and may prevent permanent limbdysfunction, as well as severe systemic complications.

Funding and support: The authors report this study did notreceive any outside funding or support.

Publication dates: Received for publication April 19, 2004.Revisions received May 24, 2004, and June 18, 2004.Accepted for publication June 29, 2004. Available onlineOctober 13, 2004.

Reprints not available from the authors.

Address for correspondence: Jennifer Cohen, MD,11234 Anderson Street, PO Box 2000, Room A108,Loma Linda, CA 92354; 909-558-4344, fax 909-558-0121;E-mail jcomd03@yahoo.com.

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3. Rosen PB, Leiva J, Ross C. Delayed antivenom treatment fora patient after envenomation by Crotalus atrox. Ann Emerg Med.2000;35:86-88.

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4. Miller T. Latrodectism: bite of the black widow spider. Am FamPhysician. 1992;45:181-187.

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8. Bond GR. Black widow spider envenomation. In: Ford M, ed.Clinical Toxicology. Philadelphia, PA: WB Saunders Co; 2000:885-889.

9. Pneumatikos IA, Galiatsous E, Goe D, et al. Acute fatal toxicmyocarditis after black widow spider envenomation [letter]. AnnEmerg Med. 2003;41:158.

10. Katalarich G. Rhabdomyolysis due to redback spider envenoma-tion [letter]. Med J Aust. 1992;157:66.

11. Malinoski DJ. Crush injury and rhabdomyolysis. Crit Care Clin.2004;20:171-192.

12. Stiles AD. Priapism following a black widow spider bite. ClinPediatr. 1982;21:174-175.

13. Clark RF, Whethern-Kestner S, Vance MV. Clinical presentationand treatment of black widow spider envenomation: a review of163 cases. Ann Emerg Med. 1992;21:782-787.

14. Diekema DS, Reuter DG. Arthropod bites and stings. Clin PediatrEmerg Med. 2001;2:155-167.

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