Caring for Patients with Blau Syndrome (BS)

Blau syndrome (BS) is a rare and chronic inflammatory disorder inherited in an autosomal dominant manner that is characterized by the childhood appearance of polyarthritis, rash, and uveitis. BS is caused by mutations in the NOD2 (also known as CARD15) gene. BS can present in a typical or atypical manner. Signs and symptoms of typical BS include granulomatous (i.e., localized nodular inflammation of granuloma tissue) polyarthritis, synovitis (i.e., inflammation of the lining of the joints), synovial cysts, a skin rash of erythematous, raised lesions with fine scales, and uveitis (i.e., inflammation of the uveal tract, which lines the inside of the eye behind the cornea). In addition to the signs and symptoms of typical BS, atypical BS affects additional organs and body systems such as the kidneys, liver, and/or peripheral nerves (e.g., causing cranial neuropathies).

Onset of BS is usually before 5 years of age and has been reported as early as 4 months of age. The first manifestation of either type of BS is usually a rash. Contractures from arthritis can develop as a potential medical complication of BS, and uveitis can result in elevated intraocular pressure (IOP), leading to vision loss. Other potential complications of uveitis include cataracts, detached retina, and glaucoma. Diagnosis of BS is confirmed by skin, synovial, or conjunctival biopsy and/or by genetic testing.