A case is presented of an 83 year old Caucasian lady who developed arsenic toxicity, secondary to chronic smoking, resulting in cutaneous changes consistent with arsenical keratosis and keratinocyte cancer.
She disclosed a 35 pack year smoking history. Across an 8 year period of routine interval full skin examinations, a surplus of 15 total basal cell carcinomas and squamous cell carcinomas were excised and confirmed with subsequent histopathological diagnosis. A prompt re-evaluation of her case for arsenic toxicity was sought.
Serum and urine levels revealed a markedly elevated arsenic level of 0.182 umol/L (normal <0.160) and 3564 nmol/24hr (normal <470), respectively. A thorough history denied evidence to indicate other sources of arsenic such as occupational exposure, or significant ingestion of possible contaminated seafood, ground or well water, or prescription or herbal medications. A trial of smoking cessation for a week and a repeat arsenical urine resulted in a near-complete resolution of her arsenic levels, favouring cigarettes as the source.
Arsenic exposure secondary to smoking may be an overlooked association. The health risks of smoking are well-established, however, Dermatologists should be aware of this unusual source and early detection with a work up for arsenic toxicity and a strong advocate for smoking cessation in the first instance should be considered.