VEXAS syndrome is a rare entity secondary to UBA1 gene mutations, located on the X chromosome. This mutation generates, as a consequence, a characteristic vacuolation on haematopoietic stem-cells. It is characterized by multiple autoinflammatory and haematologic manifestations, which respond and end up being dependent on corticosteroid treatment. In this publication we present a 2-case series diagnosed at our hospital and make a brief literature review of the published evidence so far.

A 30 year-old man with acute myeloblastic leukaemia and secondary myelodysplastic syndrome developed graft-versus-host disease. The patient was treated with ruxolitinib. After being treated for 3 months with ruxolitinib, an inhibitor of Janus kinase, he developed Aspergillus retinal necrosis resistant to common treatment. Treatment with Janus kinase inhibitors may lead to an increased incidence of opportunistic infections. Janus kinase inhibitor administration may result in poor treatment efficacy.

Granulomatous dermatitis has been associated with hematologic disorders, including the myelodysplastic syndromes. We describe the first case of granulomatous dermatitis associated with polycythemia vera, presenting as large erythematous nodules mimicking panniculitis. We also present the seventh case associated with myelodysplasia, with erythematous plaques on the face and neck, similar to a neutrophilic dermatosis. We consider it particularly interesting for dermatologists to be aware of this dermatosis as a nonspecific manifestation of various hematologic disorders. We suggest performing additional tests (complete blood count) to exclude the possibility that the skin manifestations are the initial sign of hematologic disease. Furthermore, we propose using the broader term, granulomatous dermatitis, to refer to these disorders as, although there are more reports of interstitial forms, cases with a more nodular presentation have also been published, and the importance of the diagnosis derives not from the subtype but from the relationship with an underlying disease.

Sweet\'s syndrome or acute neutrophilic febrile dermatosis is a systemic disease of unknown etiology characterized by the appearance of skin lesions produced by a neutrophilic dermal infiltrate, fever and peripheral leukocytosis. It may be associated with hematologic diseases, including leukemia, with immune diseases as rheumatoid arthritis, or can occur in isolation. The myelodysplasias are hematological disorders characterized by one or more cytopenias secondary to bone marrow dysfunction. We present the case of a patient with Sweet\'s syndrome associated with myelodysplastic syndrome and treated with glucocorticoids who did not present a good clinical outcome. We discuss the different treatment of these diseases because in most cases glucocorticoids, which are the treatment of choice in Sweet\'s syndrome, may be insufficient.