Topical nitrogen mustard therapy in patients with Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is characterized by abnormal proliferation and infiltration of Langerhans cells in different organs. The skin is frequently involved either as unisystem or multisystem disease.

To review the clinical response and side-effects of nitrogen mustard therapy in LCH in children and adults with unisystem or multisystem disease.

This retrospective study includes 10 children and four adults with LCH, treated with nitrogen mustard from 1975 to 2010. The median extent of skin involvement was 46% (range 5-100%).

Overall, 13 patients had complete or partial response. Although eight patients achieved a complete response with a median time of 12·3months (range 36 days to 1·9 years), six of these patients ultimately relapsed. One patient, who had unisystem disease limited to the skin, initially showed progression of her cutaneous lesions with nitrogen mustard treatment. Although subsequently the cutaneous lesions completely regressed, concomitant systemic involvement was noted. Four other patients similarly experienced improvement of their skin lesions with treatment, but also exhibited progression of the LCH systemically. The patients were treated with other therapies prior and adjunctive to nitrogen mustard. However, five patients had progression to other organs, despite regression of skin lesions, which supports that the treatment effect in the skin is related to topical nitrogen mustard. Six patients developed contact dermatitis to nitrogen mustard.

Topical nitrogen mustard can be an effective and safe therapy in both children and adults with cutaneous LCH, although relapses are common.