A case of mevalonate kinase deficiency, neonatal Sweet syndrome, and inflammatory bowel disease.

Mevalonate kinase deficiency is a group of rare metabolic autoinflammatory disorders that present with recurrent fevers, abdominal pain, arthralgias, adenopathy, and a variety of cutaneous manifestations. The skin findings may mimic cellulitis, erythema elevatum diutinum, IgA vasculitis, and Sweet syndrome, and there is often a morbilliform or urticarial rash and aphthous stomatitis. Mevalonate kinase deficiency is one of the identified monogenic variants that can cause very early onset inflammatory bowel disease (IBD). We present a rare case of a patient with mevalonate kinase deficiency, neonatal Sweet syndrome, and infantile-onset IBD, who has been successfully treated with canakinumab therapy.