Treatment of necrobiotic xanthogranuloma - a systematic review.

Necrobiotic xanthogranuloma (NXG) is an uncommon non-Langerhans cell histiocytosis involving skin and extracutaneous tissues. The lesions are usually asymptomatic and commonly appear in the periorbital area. Paraproteinemia is closely associated with NXG and its pathogenesis remains unclear. NXG prognosis is poor with several treatments showing variable results. Treatment of monoclonal gammopathy with alkylating agents does not necessarily influence the activity of the skin disease and vice versa. The aim of this systematic review is to summarize all reported treatments of necrobiotic xanthogranuloma of the skin, with or without underlying malignant condition and based on articles from the PubMed database using the query 'necrobiotic xanthogranuloma treatment', both in English and German, about 'human' subjects and published between 1980 and 2014, documenting adequate treatment for NXG. Mainly individual case reports, small case series and retrospective studies were found. Treatment options include topical and systemic corticosteroids, thalidomide, high-dose intravenous immunoglobulin (IVIG), chlorambucil, cyclophosphamide, fludarabine, rituximab, melphalan, infliximab, interferon alpha, cladribine, hydroxychloroquine, azathioprine, methotrexate, laser therapy, radiotherapy, surgery, PUVA, plasmapheresis and extracorporeal photopheresis. Randomized controlled trials and studies on long-term outcomes after treatment were not found and are necessary to focus on in the future.