Describe topical nitrogen mustard (HN2) therapy.

This treatment is one of the most common for mycosis fungoides in the United States, and it has been used extensively in this disease since the early 1960s. It is easy to learn, can be applied by the patient at home, and has few side effects. The treatment consists of the topical application of 10 mg of nitrogen mustard in 60 mL of water every day to the entire skin surface except the eyelids and genitalia. Complete response rates for stage 1 disease are .50%. The treatment is well tolerated with few side effects and no severe systemic side effects. Over 50% of patients will develop allergic contact dermatitis to the topical medication, and there is a long-term risk for basal and squamous cell carcinoma. Some physicians prefer to use the medication in an ointment base.

Vonderheid E, Tan E, Kantor A, et al: Long-term efficacy, curative potential, and carcinogenicity of topical mechlorethamine chemotherapy in cutaneous T-cell lymphoma, J Am Acad Dermatol 20:416–428, 1989.