PUVA therapy in persistent cutaneous histiocytosis: Case report and literature review

Background: Cutaneous and mucocutaneous histiocytosis (group C) comprise a wide variety of entities affecting skin and/or mucosae. Although they are considered as reactive proliferations, their exact pathophysiology remains unknown and, therefore, they lack a specific treatment.

Aims: The aim of this study is to review the evidence on cases of histiocytosis treated with UVB and/or UVA and to report a new case of relapsing group C histiocytosis that has been successfully treated with PUVA therapy.

Materials & methods: We have conducted a review of the literature published over the last 40 years on the treatment of histiocytosis with phototherapy in the online PubMed database. We also describe a new case of successful treatment of histiocytosis with PUVA therapy.

Results: Our patient was a 27-year-old man with persistent outbreaks of cutaneous histiocytosis over the previous 8 years. He responded successfully to PUVA therapy, and no relapse has been detected after one year of follow-up.

Discussion: Self-involution is usual in group C histiocytosis, so conservative management is usually the first approach. Relapsing cases pose a therapeutic challenge. Reported treatment options for these patients include isotretinoin, cryotherapy, immunosuppressants, low-dose chemotherapy, CO2 laser, radiotherapy, and surgery. Phototherapy and photochemotherapy have been used in a small number of patients with considerable success. The main limitation to provide firm recommendations on histiocytosis therapy is the absence of solid evidence, as the articles published are mainly case reports with a short follow-up. In our patient, despite the short follow-up we have considered photochemotherapy to be effective since no spontaneous remission had been achieved in the previous 8 years.

Conclusion: PUVA therapy could be a safe and effective option to treat persistent cutaneous manifestations in patients with histiocytosis, although more evidence is required to support this statement.