Whilst impaired IL-1 results in immunodeficiency characterized by susceptibility to Staphylococcus aureus, Streptococcus pneumoniae, and Pseudomonas aeruginosa infections (181), deficiency of IL-1Ra leads to a syndrome of sterile multifocal osteomyelitis, periostitis, and pustulosis caused by unrestrained IL-1-mediated inflammation (DIRA) (47). Here, IL1A is linked to periostitis.