Successful therapy of Pyoderma gangrenosum with a JAK2 inhibitor

We present a case of a 64‐year‐old white European woman with polycythaemia vera (PV) (diagnosed in approximately 1980) who for the past 6 years had painful pyoderma gangrenosum (PG) ulcers on both legs. In 2011 she presented herself for the first time at a dermatological clinic with progressively painful bilateral ulcers. The ulcers started, a few months previously, as a pustule with rapid growth, tissue necrosis and enlargement of the area. An angiological examination, a digital photoplethysmography, a colour‐coded ultrasound and a compression ultrasound revealed a regular arterial and venous system. The skin biopsy was compatible with PG. Known to occur in association with inflammatory and haematological disorders, the aetiology and pathogenesis of PG remains unclear.

Experiencing chronic severe pain, the patient presented herself at our clinic in August 2013 with the ulcers shown in Figure 1. Because of the availability of new tests, a re‐evaluation of the mutation analysis was performed showing a JAK2 exon 12 mutation, which is less frequently seen in patients with PV compared with the JAK V617F mutation.1 The laboratory analysis revealed leucocytosis and erythrocytosis, and the physical examination showed splenomegaly. After being treated with phlebotomies and hydroxyurea for her PV, she evolved bone marrow fibrosis accompanied by marked splenomegaly and thrombocytopenia.