Footnotes

• Contributors MLS: primary manuscript author, evaluated patient, performed excision of patients for squamous cell cancers, arranged with the aid of Nurse My Ton the acquisition of the arsenic-containing traditional medicine formulation that the patient used and arranged testing of the traditional medication for assessing the concentration of arsenic within the medication. DL: evaluation and assessment of the patient, provided ongoing care and evaluation to the patient, performed later biopsy for patient and excision of lesion of skin malignancy and edited manuscript in ongoing basis. JCS: toxicology and pharmacology, expertise within the field of arsenic toxicology and pathomechanisms of arsenic-induced carcinogenesis. He has had very significant involvement in manuscript editing and has been a primary Discussion section contributor. MVH: evaluation/assessment and initial treatment of the patient, excising the large two primary acral-located squamous cell carcinoma lesions, and followed postsurgical wound care after these lesions, diagnosed patient with arsenic-induced malignancies by hair sample analysis, provided initial data, involved in review of the manuscript and checking accuracy for the clinical care and diagnostic aspects.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent Obtained.

• Provenance and peer review Not commissioned; externally peer reviewed.