Histological comparison of skin damage between hydrochloric acid exposure and typical postmortem skin changes: Establishing a novel database for Dermatological Pathology

Abstract

Background: Hydrochloric acid (HCl) is a widely used industrial chemical that can cause severe tissue damage upon contact. Studying the distinctive histopathological patterns can help forensic pathologists accurately identify cases of acid burns.

Objectives: To investigate the effects of skin tissue exposure to 20.0% HCl and compare these effects with the usual post-mortem changes after death following an extended postmortem interval (PMI)

Methods: An experimental, prospective, descriptive data collection study was conducted from 2023 to 2024, encompassing 32 human cadavers’ skin from the Department of Forensic Medicine department, Chulalongkorn University, Bangkok,Thailand. Samples were divided into three groups: control (no HCl exposure), exposed to 20.0% HCl for 3 minutes, and exposed to 20.0% HCl for 10 minutes. Skin specimens were fixed in 10.0% formalin, embedded in paraffin wax, and stained with hematoxylin-eosin (H&E) and Periodic acid-Schiff (PAS). Histological alterations were evaluated under light microscopy.The histologic features of postmortem skin change were descriptively documented.

Results: In control samples, postmortem changes included partial disruption of the basket-weave (BV), vacuolization of the basal layer, thickening of upper collagen fibers, papillary dermis, and swelling of skin appendages. With prolonged PMI,features of dermo-epidermal separation were observed. When skin is exposed to 20.0% HCl, coagulative necrosis increases with longer exposure times, leading to homogenization and coagulative necrosis in the dermis.

Conclusion: Skin exposure to 20.0% HCl leads to progressive histological damage that differs from natural changes seen in postmortem skin.