Dermatopathological findings of Bothrops atrox snakebites: A case series in the Brazilian Amazon

PLoS Negl Trop Dis. 2024 Dec 26;18(12):e0012704. doi: 10.1371/journal.pntd.0012704. eCollection 2024 Dec.

Abstract

Background: Bothrops venom consists primarily of metalloproteinase and phospholipase A2 toxins, which are responsible for the acute inflammatory, coagulant and hemorrhagic action following snakebite. The local effects of snakebite envenomation by Bothrops species are particularly prevalent yet poorly studied, but include pain, edema, erythema, blistering, bleeding, and ecchymosis.

Methods and findings: In this study, we describe the dermatopathological findings observed in a series of 22 patients diagnosed with Bothrops envenomation treated in a tertiary hospital of Manaus, in the Brazilian Amazon. Clinically, pain and edema were observed in all patients, followed by fang marks (63.6%), secondary infection (36.3%), ecchymosis (31.8%), erythema (22.7%), blister (13.6%), and necrosis (4.5%). Regarding histopathological findings, epidermal alterations such as spongiosis, acanthosis and hyperkeratosis were the most observed characteristics in our cases series, with isolated cases of hyperplasia, hemorrhagic intraepidermal blister and severe necrosis. Changes in dermis and hypodermis consisted mainly of hemorrhage, inflammatory infiltrate, edema, congestion, and vascular damage, whereas cases of collagen damage, necrosis, abscess, and signs of tissue repair, indicated by the presence of granulation tissue, were also observed, with a persistence of inflammatory and hemostatic alterations even days after antivenom administration. Therefore, the tissue damage resulting from Bothrops envenomation could be related to both direct venom activity as well as inflammatory response or presence of infectious process. The histopathological analysis of human skin injury can enlighten the pathological and endogenous effects of local envenomation and could underpin new strategies, including novel treatments, adjuvants or changes in clinical management, that lead to better outcomes in snakebite patients.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Antivenins / therapeutic use
  • Blister / pathology
  • Bothrops atrox
  • Bothrops*
  • Brazil
  • Child
  • Crotalid Venoms / toxicity
  • Edema / pathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Necrosis
  • Skin / pathology
  • Snake Bites* / complications
  • Snake Bites* / pathology
  • Young Adult

Substances

  • Crotalid Venoms
  • Antivenins

Grants and funding

Financial support was provided in the form of grants from Fundação de Amparo à Pesquisa do Estado do Amazonas - FAPEAM (Pró-Estado Program #002/2008, #007/2018 and #005/2019, to W.M.; POSGRAD Program #002/2024 and AMAZÔNIDAS Program #002/2021, to J.S.; PhD fellowships - 038/2022 - PDPG, to F.B.A.B, J.C.F.N, and T.P.N.), Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq (Research fellowships 305762/2022-2 to A.G.C., 311434/2021-5 to J.S., and 303207/2020-7 to W.M.) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES (PhD scholarship - #001 to H.N.S.I). The funders had no role in study design, the decision to publish, or preparation of the manuscript.