We have concerns regarding the article, “A New Therapy for Brown Recluse Spider Bites,” by Chris Schulze, MD. (2020;42:28; http://bit.ly/32J2qJx.) We appreciate innovations in the management of overdoses and envenomations, but the article falls short in the evidence substantiating a brown recluse envenomation and that supporting trichloroacetic acid (TCA) therapy.
The lesions sustained by Dr. Schulze are not likely envenomations. Brown recluse envenomations are almost always singular and have a red-white-blue pattern: hyperemia most external to the bite, intermediate central white tissue of poor vascularity, and a most central blue, necrotic ulcer. (“Loxosceles Spiders” in Critical Care Toxicology. 2004, p.2577; JAMA Dermatol. 2017;153:377.)
True brown recluse envenomations are uncommon and unlikely to be found in multitude. These spiders are characteristically reclusive; consider the family of four in Kansas who lived in a home with more than 2000 brown recluse spiders without a single family member experiencing an envenomation. (J Med Entomol. 2002;39:948.)
The author lamented that the characteristic late development of necrosis leads to delays in treatment, but there is no proven or routine treatment (despite investigation of dapsone, early surgical debridement, glucocorticoids, metronidazole, diphenhydramine, cyproheptadine, hyperbaric oxygen, and electric shock therapy). (N Engl J Med. 2005;352:700.) Of significant note, systemic loxoscelism was not mentioned, which is a life-threatening and potentially rapidly fatal complication of brown recluse envenomation.
The potential negative implications regarding TCA are broad. It has no published scientific support for use in brown recluse-related cytotoxic necrosis. TCA is a dermal irritant and could be injurious. The case report did not provide a physiologic theory for the benefit of TCA, and it is possible that a patient may use this at-home remedy and delay care of an alternative dermatologic issue. We recommend that emergency physicians recognize these significant issues and implications on patient care when considering treatment.
We appreciate the challenge in determining new treatments when the literature is sparse, but it is imperative to critically appraise the quality of evidence surrounding a suggested treatment.
Mary Billington, MD
Kurt Kleinschmidt, MD
James Dazhe Cao, MD
Dr. Schulze responds: The envenomations I experienced cannot conclusively be diagnosed as the effect of brown recluse spiders. I was uncertain and sought more expert evaluation. The multiplicity of lesions was a problem, but the bites occurred in early spring (and in an appropriate setting), when the juveniles are newly hatched. Unfortunately, I do not have photos of the original lesions because I was initially unaware of their significance, but the progression of the wounds was consistent with a brown recluse spider bite. If not, then my response to the bite was abnormal (and my wound healing and response to insect bites and stings seem normal otherwise) or there is something new (and cool and scary) in Texas able to produce similar necrotizing lesions.
I did not mention loxocelism because of the length limitations of the article, the extreme rarity of the condition based on my literature search, and the inappropriateness of the described treatment using the methods described. Loxocelism is a completely different problem—it is systemic rather than local and topical.
The dangers of TCA are discussed in the article, and the article was presented in a respected medical publication (rather than being broadcast on a blog) for the medical community (rather than for the public). Despite its dangers, TCA is available to and used by the public, which is also noted in the article.
The article was originally conceived as a case report of some serendipitous and unexpected findings that might have future clinical significance, and the brief introductory review was added at the request of the editor. It was never intended to be comprehensive or authoritative but to share my interesting findings, which, again as noted in the article, need further investigation.