Successful treatment of scleromyxoedema with daratumumab

Scleromyxoedema is a rare mucinous disease associated with monoclonal gammopathy. Treatment can be difficult, especially in severe cases with extracutaneous involvement such as dermato-neuro syndrome.1 A 51-year-old female patient with scleromyxoedema was referred to our haematology department in 2008. She had first been diagnosed in 1992 and was known to have accompanying monoclonal gammopathy of undetermined significance (MGUS), type IgG Kappa. The patient suffered from sclerosing skin lesions (upper left image) that significantly impaired her quality of life. Treatment initially consisted of topical application of steroids and retinoids, PUVA and Er: YAG laser as well as systemic treatment with steroids and immunoadsorption. During the course of her disease, she had developed dermato-neuro syndrome characterised by generalised complex focal seizures. As a result, she required intensive care treatment including assisted ventilation several times. Due to dermato-neuro syndrome and worsening of skin lesions, the patient received various systemic treatments, all of which consisted of agents commonly used in myeloma therapy. These included dexamethasone in combination with melphalan, bortezomib or lenalidomide; high-dose melphalan with autologous stem cell transplantation was performed in 2014. Some of these treatments led to a partial response of her monoclonal gammopathy and improvement in skin lesions; however, such responses were always short-lived. Due to exuberant tissue growth on the nose, a surgical dermabrasion, excision and skin transplantation were performed. Following the reoccurrence of seizures despite monthly intravenous immunoglobulin infusions, it was decided to start her on daratumumab monotherapy. Six months after the start of daratumumab, M protein level was undetectable for the first time. Even more astonishing was a rapid and durable improvement in skin manifestations (upper right image) and a persistent absence of seizures. Because of worsening sensory neuropathy possibly related to daratumumab, treatment was stopped in January 2021. However, M protein levels remain low (lower image), and there is no reoccurrence of skin lesions to date. The patient remains free of dermato-neuro syndrome and her general condition improved remarkably. To our knowledge, this is the first report of antiCD38-antibody treatment for scleromyxoedema. Open Access funding enabled and organized by Projekt DEAL.