Twenty-two children with fibromyalgia (FM), found in a population based study of 1756 Finnish preadolescents, were prospectively and blindly followed for one year to investigate their physical and psychological background factors and to determine the one year persistence of FM.
The American College of Rheumatology 1990 criteria for FM were used. Widespread pain was determined with a structured, pretested pain questionnaire, including items on disability both at baseline and at followup. At baseline, hypermobility was tested with Beighton's method and aerobic capacity with a 20 m shuttle run test, and psychological data were collected using the Children's Depression Inventory (CDI), a sleep questionnaire, and the Child Behavior Checklist and Teacher's Report Form. At followup, evaluations with the CDI and sleep questionnaire were repeated.
At baseline, the prevalence of FM was 1.3% (95% CI 0.8 to 1.9). At followup, 16/22 (73%) children were available for evaluation; 4 (25%) had persistent FM. Children with FM had low pain thresholds. Only one of 19 children had hypermobility. Those with persistent FM had persistent subjective disability. Depressive symptoms diminished, but there was still comorbidity of pain and depressive symptoms at followup.
This study supports a previous one, in which FM in children had a good outcome. However, fluctuation of pain symptoms in children might partly explain the outcome. Children with persistent FM showed persistent disability with a number of distress symptoms.