Systemic effects and skin injury after experimental dermal exposure to monochloroacetic acid

Abstract

There have been many fatal occupational accidents of skin exposure to monochloroacetic acid (MCA). However, there have been no reports of dermatological findings and the lethal consequences have not yet been demonstrated. Therefore, harmful local and systemic effects were investigated after dermal exposure to MCA. A 0.5 mL aliquot of MCA solution (40% w/w) was applied to the abdominal skin of ten 10-week-old male SD rats under anesthesia. The exposure area (25 x 25 mm2) was 1.6% of the total surface area. The dose of MCA per area was 34.1 mg/cm2. Saline was similarly administered to 10 control rats. Histopathological findings after 10 min were observed by light microscopy. Blood samples were collected by exsanguinations from the carotid arteries after 4 h. Skin samples were collected 10 min after the initial exposure. Histological findings showed severe degeneration of collagen bundles in the epidermis and subcutaneous tissues. P(CO2), HCO(3)-, TCO2, BE and glucose levels were decreased in the MCA group. AST, m-AST, ALT, BUN, Cr, NH3, lactic acid, pyruvic acid, RBC, Hb, Hct, total protein and albumin were increased in the MCA group. The burn was determined to be a third-degree burn on the basis of the histopathological findings. The severe toxicity was probably a consequence of the rapid permeability. Biochemical parameters were a consequence of hepatocellular injuries, renal dysfunction, dysglyconeogenesis and dysfunction of ammonia metabolism. MCA reportedly enters the TCA cycle and inhibits aconitase. MCA metabolites also inhibit pyruvate carboxylase in the gluconeogenesis pathway. Therefore, the important serum biochemical abnormalities such as hypoglycemia and lactic acidosis should be monitored to find the acute systemic disorders.

Therapeutic applications of dichloroacetate and the role of glutathione transferase zeta-1

“…Although glyoxylate is the major primary metabolite of DCA, treatment of animals with high doses of DCA has resulted in detection of small amounts of monochloroacetate (MCA) in blood and urine (Shroads, et al, 2008). The concentrations were low, however this was of concern because MCA is neurotoxic (Berardi, et al, 1987; Lu, et al, 2015) and toxic to the liver and kidney (Dote, et al, 2003). Further discussion of the mechanism of toxicity is presented in section 11.4.…”

Iatrogenic Full-Thickness Chemical Burns from Monochloracetic Acid

“…Fullthickness burns to the skin have only been demonstrated during dermal exposure in experimental animals to MCA. 3 This case is the first one reported of a human full-thickness burn after MCA application; the injury most likely resulted from the high concentration used in combination with curettage and the long duration of contact which included reapplication. A case of partial-thickness burns after the application of this compound has been reported.…”

“…5 The mechanism for this process may be related to the disruption of the tricarboxylic acid cycle. 3 Although our patient initially demonstrated evidence of systemic upset, this rapidly settled, and there was no evidence objective of metabolic organ insult. This upset was probably the result of the small area of contact and the physiological reserve found in a young and fit adult.…”

An unusual and serious complication of topical wart treatment with monochloroacetic acid

“…The solution, flake, and molten forms are corrosive to the skin and cause protein hydrolysis, inflammation, and cell destruction within tissues 1,4 . It has been reported in an experimental study on rats that MCAA at a concentration of 40% causes serious collagen band destruction in the epidermis and subcutaneous tissues; this observation was shown to be a full‐thickness burn 5 . Numerous case reports of skin exposure to MCAA, causing partial or full‐thickness burn injuries, have been described, most of which were mortal 1,4–7 .…”

“…In addition to wart treatment, it is used for industrial purposes, such as the synthesis of certain organic chemicals 1,4 . Numerous articles and experimental studies have reported chemical burns and systemic toxicity related to MCAA exposure 1,4–7 . In all of these reported cases, a high MCAA concentration was used.…”