We read with interest your case report of a patient's death from a suspected black widow spider envenomation (Gaisford, K, Kautz DD. Black widow spider bite: A case study. Dimens Crit Care Nurs. 2011;30(2):79-86). As medical toxicologists, we certainly appreciate your discussion of the pathophysiology of black widow venom. However, we feel this article gives the reader the wrong impression about the presentation of a black widow envenomation and further contributes to the misunderstanding of "spider bites" that are present among patients and health care workers.
As described in the article, black widow venom is neurotoxic, causing release of neurotransmitters at the nerve terminal with resultant downstream physiological effects. Within minutes to hours of the bite, victims may develop localized pain, which may further progress to intense muscle spasms, nausea, vomiting, tachycardia, and hypertension. The muscle cramps of latrodectism typically migrate proximally from the site of the bite, resulting in intense chest or abdominal pain, and may increase over time, mimicking other medical pathology such as acute myocardial infarction, aortic dissection, or a surgical abdomen. It is the intense pain that typically causes envenomated patients to seek medical care, often requiring intravenous opioids and benzodiazepines for symptomatic relief. Cutaneous symptoms are generally not a prominent feature in black widow envenomation and may include mild erythema with a surrounding halo or localized diaphoresis. Large areas of necrosis as described in the article are not a feature consistent with black widow envenomation.1 Death is rare from black widow envenomation, and around 75% of patients bitten develop only local symptoms.2
In the case presented, the patient described local effects with some systemic symptoms approximately 2 hours after the bite. However, when she arrived at the hospital 18.5 hours after the inciting event, there was no description of muscle spasms, rigidity, or progressive systemic pain. Because of release of norepinephrine with [alpha]-latrotoxin, patients become hypertensive, which she did not experience. The patient developed a necrotic-appearing area that was approximately 23 x 14 cm in dimension. While any puncture wound, including a spider bite, could be a nidus for bacterial infection, necrosis is not a feature of [alpha]-latrotoxin and is more consistent with Streptococcus pyogenes that was grown from her wound. From the laboratory values that were presented, it appears the patient experienced disseminated intravascular coagulation (DIC) and septic shock, also features not consistent with [alpha]-latrotoxin.
Given the presentation, the timing of progression of symptoms, and her autopsy report, her clinical picture is more consistent with septic shock, DIC, and multiorgan system failure from necrotizing fasciitis, with a break in the skin or puncture being a possible nidus of infection. Although there are some features that could also be attributed to [alpha]-latrotoxin, her clinical picture is not consistent with a black widow spider bite.
"Spider bites" are common patient presentations to both emergency departments and clinics. Although spiders with neurotoxic and cytotoxic venom are both indigenous to the United States, care should be taken to consider other pathology before the diagnosis of a spider envenomation is made. Black widow spider envenomation typical presents as a progressive pain syndrome with minimal cutaneous symptoms. In the United States, hobo spider or brown recluse spider envenomation may result in necrotic skin lesions, but commonly infection, abscess, or other underlying medical problems, such as pyoderma gangrenosum, are misdiagnosed as spider envenomation, delaying appropriate treatment and potentially compromising patient care.3
As we head into warm weather in much of the United States and the population is spending more time outdoors, we feel it is important to educate health care providers on the clinical syndrome of a black widow spider envenomation. Black widow bites can result in the need for hospitalization; however, there are other disease processes that have the potential to be even more deleterious if they are not seriously considered in the differential diagnosis.
Author's Response
We are honored that Drs Borek and Charlton responded to our article and appreciate their endeavors to correct misconceptions held by health care providers about clinical manifestations and treatment of spider bites. We are especially glad that we included the laboratory results and detailed descriptions of "Pam's" clinical manifestations and treatment in our article, as these detailed allowed them as experts to make a differential diagnosis. Their insights reinforce the need to consult medical toxicologists and other medical specialists when caring for a patient like Pam. In addition, since this article came out in print, we have also learned that Pam's "bite" would be considered "unconfirmed" because the spider was not collected and identified during or immediately after the bite.
Dr's Borek and Charlton's response also reinforces our plea to critical care nurses to seek out resources to better understand our patients, even after the patients are no longer in our care. Finally, we reiterate our point that every patient is different, but each one has something to teach us about the physiology and pathophysiology of his/her illness.
Submitted by:
Kristine Gaisford, MSN, RN, CCRN
Clinical Supervisor
Marion Health Care Services
Salisbury, NC
Donald D. Kautz, PhD, RN, CRRN, CNE
Associate Professor of Nursing
The University of North Carolina at Greensboro
[email protected]
References