C-reactive protein in measles.

Seventy-two children with early measles (1st-3rd day of rash), presenting at two centres in Santiago, Chile, were classified as having mild ('ordinary measles', n = 50), or moderate to severe measles ('primarily severe measles', n = 22). The level of serum C-reactive protein (CRP) was determined by nephelometry from a finger prick sample. The mean CRP value in ordinary measles, 19 mg/l, was significantly lower (P less than 0.001) than in primarily severe measles where the mean CRP was 65 mg/l. During late measles (5th-8th day of rash), the mean CRP was 19 mg/l if the child recovered uneventfully (n = 35), whereas the mean level of 123 mg/l (P less than 0.001) was encountered when the child suffered from complicating pneumonia (n = 22). We conclude that the simple quantitative CRP determination is a useful alarm signal during the course of measles: elevated levels point to severity or complications in recovery.