Myelopathy and peripheral neuropathy can also occur. Renal involvement is rare, however, these children are at risk for the development of nephrocalcinosis which may be asymptomatic. Serum and urinary calcium levels probably contribute to this development, but other factors are likely to be involved. For children under 4 years of age, sarcoidosis is characterized by the clinical triad of rash, arthritis, and uveitis. Pulmonary complaints are infrequent but lung disease may develop years later.
Sarcoid arthritis is persistent and nondestructive, affecting predominantly the large joints.
Skeletal and eye involvement seem to be more frequent in this age group. Posterior synechia, uveitis, optic atrophy, miliary retinitis, and granuloma of the conjunctivae and optic nerve have all been described. Uveitis may be the initial and dominant manifestation of the disease. The activity of uveitis does not necessarily parallel that of the joint disease and may produce few symptoms. However, the most devastating complication is secondary glaucoma.