Pyoderma gangrenosum following initiation of immune checkpoint inhibitor therapy

Pyoderma gangrenosum (PG) is an ulcerating neutrophilic dermatosis that is often associated with the underlying systemic disease. For example, PG is often a common presenting symptom in patients with hematologic malignancies, most commonly myelodysplastic syndrome (MDS). Here, we present the case of a patient who developed PG and a lichenoid drug eruption after the initiation of ipilimumab and nivolumab immune checkpoint inhibitor (ICPI) therapy. Lichenoid drug eruptions are well known to be associated with ICPI therapy, particularly nivolumab. However, only one case of PG has been reported in association with ipilimumab and no cases have ever been reported with nivolumab. Awareness that PG can be associated with ICPI therapy in patients with MDS can allow physicians to be better prepared to help in early recognition and early treatment to prevent the spread of disease.