Arsenic Keratosis in a Patient from Newfoundland and Labrador, Canada

Abstract

Background and Objective: Millions of people worldwide suffer from chronic arsenic poisoning due to contaminated drinking water. The devastating effects of chronic arsenic ingestion are multisystem, but depending on the dose and frequency of exposure, may take many years to become clinically apparent. The earliest and most common manifestations are dermatological, and therefore, recognition of hallmark lesions is key. In this report, we describe a suspected case of palmoplantar arsenical keratosis in a patient from Newfoundland, Canada. Methods: Case report and review of relevant literature via PubMed search. Results: A 64-year-old fisherman from rural Newfoundland presented with a 12-year history of hyperkeratotic palmoplantar papules/plaques. The lesions first appeared on the sole of his left foot but gradually extended to involve the sole of his right foot and palms. Numerous violaceous keratotic papules with erosions were observed. Both the patient and his wife were found to have elevated blood arsenic levels, and the arsenic concentration in their artesian well was 14.2 ug/L (maximum acceptable concentration: 10 ug/L). Interestingly, biopsy showed a lichen-sclerosis-like inflammatory pattern that seems to deviate from the classic histologic description. The patient is being treated with oral acitretin, and minor improvement has been noted. Conclusion: It is important to consider arsenic exposure whenever a patient presents with acral hyperkeratosis. Further research is needed to develop more effective treatments for chronic arsenicism and to determine the effects of very low-dose exposure and what truly constitutes a safe level.