Joint and limb symptoms in children after immunisation with measles,mumps, and rubella vaccine.

OBJECTIVE--To assess whether the combined measles, mumps, and rubella vaccine increases the incidence of joint and limb symptoms in young children. DESIGN--Comparison of six week recalled incidence of symptoms in two groups of children: children who had been immunised at the start of the six weeks, and children eligible for immunisation but who had not received it. SETTING--South Manchester Health Authority. SUBJECTS--2658 children immunised during July 1989-February 1990 and 2359 not yet immunised. Questionnaires were returned for 1846 immunised children and 1075 not immunised. MAIN OUTCOME MEASURE--Recalled rate of joint and limb episodes determined by postal questionnaire and later by clinical follow up. RESULTS--Compared with non-immunised children the immunised group had an increased incidence of new episodes (relative risk 1.6 (95% confidence interval (1.2 to 2.1)) and first ever episodes, though this was not significant (1.7 (0.3 to 3.5)). The risk of first episodes was increased in girls (3.5 (1.1 to 12.2)) but not in boys (1.0 (0.4 to 2.6)). Similarly, an increased risk was seen in children aged under 5 (12.0 (1.6 to 92.3)) but not in older children (0.7 (0.3 to 1.5)). Most episodes were mild and self limiting, but three immunised children required hospital referral. CONCLUSION--Measles, mumps, and rubella vaccine is associated with an increased risk of episodes of joint and limb symptoms, especially in girls and children under 5. The risk of frank arthritis is substantially less than after wild rubella infection.