Various forms of arsenic-containing medicine are still being used in many parts of the world, including Thailand.1 Patients with chronic arsenic toxic effects may have internal cancers and many cutaneous lesions such as those associated with Bowen disease (BD), arsenical keratoses (ArKs), squamous cell carcinomas (SCCs), and basal cell carcinomas (BCCs).1 These patients generally have multiple recurrent skin cancers and precancerous lesions.
Waranya Boonchai. Treatment of Precancerous and Cancerous Lesions of Chronic Arsenicism With 5% Imiquimod Cream. Arch Dermatol. 2006;142(4):531–532. doi:10.1001/archderm.142.4.531