Sweet syndrome as terminal event in ruxolitinib-treated myelofibrosis.

A 77-year-old woman with post-essential thrombocythaemia myelofibrosis was admitted to hospital with general deterioration in well-being and multiple pustular lesions and swelling of both hands. She had been commenced on ruxolitinib 18 months prior to this admission, for management of symptomatic splenomegaly and constitutional symptoms related to her myelofibrosis. After an initial excellent response to therapy, she started to develop recurrent staphylococcal skin infections and subcutaneous abscesses, some requiring prolonged antibiotic courses and surgical drainage. Twelve months after starting ruxolitinib, the medication was tapered down due to loss of response (progressive splenomegaly and constitutional symptoms). This acute admission was 2 weeks after stopping ruxolitinib. The patient was initially commenced on antimicrobials for presumed skin infection but the lesions continued to progress and involved her hands, abdomen, back and legs. A biopsy from a lesion in her hand indicated a diagnosis of acute neutrophilic dermatosis (Sweet syndrome) (images). The patient was started on oral corticosteroids with little improvement. She went on to develop worsening constitutional symptoms of sweats, anorexia and fatigue. The aggressive nature of her skin lesions suggested possible leukaemic transformation, but this was not supported by her blood count (i.e. no increase in blast percentage and no progressive cytopenias). A bone marrow examination was deemed inappropriate due to her substantial decline in health and her frailty. Dapsone was initiated in an attempt to control the skin lesions and the patient was discharged for palliation of symptoms, predominantly of pain arising from the skin lesions; unfortunately she died soon after. Sweet syndrome is a rare reactive skin condition characterized by fever, leucocytosis and painful skin lesions. The condition is usually associated with malignancies, particularly haematological. Lesions may be bullous or ulcerative, often resembling atypical pyoderma gangrenosum, and can also resemble skin infection. If associated with malignant conditions, Sweet syndrome can be aggressive and resistant to treatment as in this patient.