Topical mechlorethamine in the treatment of mycosis fungoides. Uniformity of application and potential for environmental contamination.

Topical mechlorethamine hydrochloride is commonly used in the treatment of mycosis fungoides and has been formulated in both aqueous and ointment vehicles. Two concerns regarding the topical application of mechlorethamine hydrochloride relate to the adequacy of skin coverage that can be attained by the patient and the extent to which others in the patient's household might be exposed to the drug. In this study six patients applied either aqueous or ointment vehicles containing a fluorescent dye. Subsequent examination of the skin under a Wood's lamp revealed a significant percentage of body surface area to be missed during application; several areas were noted to be missed most commonly. These observations have led to specific alterations in instructions given to patients regarding drug application. Examination of the surrounding environment showed minimal evidence of contamination.