Treatment of Arsenic-Induced Bowen’s Disease With Topical 5-Fluorouracil

Arsenic is a well-established carcinogen that increases one’s risk of developing squamous cell carcinoma, classically resulting in multiple lesions and involving the palms and soles after decades of latency.^1,4 A common source of exposure to arsenic occurs via ground water in developing countries with unpurified sources. For instance, a large-scale study found that more than 20% of adults in Bangladesh had elevated serum arsenic levels after chronic intake of their drinking water.² A plethora of treatment options exist for the treatment of Bowen’s disease, and the use of these medications in different combinations has yielded varying degrees of disease eradication. Acitretin has been used successfully both with and without 5-FU.^5,6 In this case report, we demonstrate the high efficacy of topical 5-FU cream when diligently applied.

A 53-year-old woman was referred to the dermatology clinic with multiple erythematous, crusted, hyperkeratotic plaques on her arms, trunk (Figure 1), scalp and hyperkeratotic papules of palms and soles (Figure 2). There was no evidence of lymphadenopathy or hepatosplenomegaly. Biopsy revealed squamous cell carcinoma in situ on her left mid-back, which revealed an acanthotic epidermis with full-thickness atypical keratinocytes with no dermal invasion (Figure 3). Prior to the biopsy, the patient reported a six-year history of severely painful, itching lesions on her scalp, head, torso, arms, palms, and soles. Per the patient’s husband, she had become extremely frustrated and depressed by her condition and was contemplating suicide periodically. The patient is from Bangladesh and has a history of extensive well water consumption from that area. She had no