Sicca Syndrome Associated with Immune Checkpoint Inhibitor Therapy

Sicca syndrome has been reported as an immune-related adverse event (irAE) of immune checkpoint inhibitor therapy (ICI) for neoplastic diseases. Severe dry mouth (interfering with eating or sleeping) developed abruptly, typically within 90 days, after initiation of ICI therapy. Salivary gland biopsies demonstrated mild-to-severe sialadenitis distinct from Sjögren's syndrome, with diffuse T-cell lymphocytic infiltration and acinar injury. Recognition of the cardinal features of ICI-induced sicca will spur appropriate clinical evaluation and management, including withholding of the ICI and corticosteroid, initiation. This characterization should help oncologists, rheumatologists, and oral medicine specialists better identify patients that develop ICI-induced sicca to initiate appropriate clinical evaluation and therapy to reduce the likelihood of permanent salivary gland dysfunction.