Delayed manifestations of congenital rubella.

The manifestations of congenital rubella syndrome (CRS) can be grouped according to time of onset into newborn, extended, and delayed CRS. The delayed manifestations are not present in early life and include the following: endocrinopathies: diabetes, thyroid disease, and growth hormone deficiency; deafness; ocular damage: glaucoma, keratic precipitates, keratoconus, corneal hydrops, and absorption of the cataractous lens; vascular effects: fibromuscular proliferation of the intima, sclerosis of arteries, systemic hypertension secondary to renal disease, and subretinal neovascularization; and progressive rubella panencephalitis. Several mechanisms of pathogenesis of the damage have to be considered for the delayed manifestations, including growth of the virus in tissues, resulting in a reduced growth rate and shortened life-span of the cells; autoimmune responses, initially stimulated by the infection; genetic susceptibility; vascular damage by the viral infection with further stenosis or occlusion of the vessels later; reactive hypervascularization; and chronic persistence of the virus in the tissue with subsequent extension of the infection to other areas.