Deficiency of interleukin-1 receptor antagonist (DIRA) is a life-threatening autoinflammatory disorder that typically manifests at birth or in the early neonatal period, although later onset in infancy and childhood has also been reported. It is characterized by cutaneous pustulosis, multifocal aseptic osteomyelitis, inflammatory arthritis, periostitis, nail abnormalities, and increased levels of acute phase reactant proteins.

DIRA is typically inherited in an autosomal recessive pattern. About one-third of patients with this disease are born prematurely or small for gestational age. DIRA is caused by loss of function mutations in the IL1RN gene, which codes for the interleukin-1-receptor antagonist, with subsequent loss of inhibition of the IL-1 receptor. This in turn causes signal activation by IL-1, leading to downstream systemic inflammation in the skin and bones.