Currently the effect of IL-1 blockade on ulcerative colitis (UC) is still ambiguous. This case report describes a patient with UC who developed severe complications after an episode of azathioprineinduced pancytopenia including cytomegalovirus pneumonitis, hemophagocytic lymphohistiocytosis, and probable pulmonary aspergillosis. Imaging after the hospitalization revealed a severe disseminated chronic candidiasis and persisting inflammation was seen. Genetic testing revealed heterozygous variants in NOD2 and NLRP12, and cytokine testing showed an increase in IL-1Ra, IL-18, CXCL9, and CXCL10. Consequently an IL-1 mediated autoinflammatory syndrome was suspected. Simultaneously, the patient developed a corticosteroid dependent UC flare-up. Treatment with anakinra was initiated for the IL-1 mediated disease which quickly induced remission of both the inflammatory syndrome and the UC.