RESUMEN
<p><b>OBJECTIVE</b>To study the clinical features of juvenile primary fibromyalgia syndrome (FMS) and to evaluate outcome after treatment.</p><p><b>METHODS</b>Six patients with juvenile primary FMS were registered in department of rheumatology and their clinical data were assessed, including degree of pain (visual analog scale, VAS), fatigue, depression, anxiety, sleep disturbances, arthrodynia, subjective joint swelling, abdominal pain, irritable bowel symptoms, urinary urgency, dysmenorrhea, morning stiffness, paresthesias, illness changes with weather, feeling worse with exercise, laboratory examination and outcome of treatment.</p><p><b>RESULTS</b>Abdominal pain was the first symptom in 5 of the cases with juvenile primary FMS, diffuse aching and left knee pain were the first symptoms in one patient. All the 6 patients were misdiagnosed prior to their rheumatological evaluation. Diffuse aching, fatigue, sleep disturbances, illness changes with weather and feeling worse with exercise existed in all the 6 patients (100%), the mean pain score was 8.8 and the mean initial tender points (TP) count was 13.7. Arthrodynia, subjective joint swelling, abdominal pain, irritable bowel symptoms and urinary urgency existed in 5 of the 6 patients (83%). Dysmenorrhea existed in 4 (67%), depression in 3 (50%), morning stiffness in 2 (33%), paresthesias in 2 (33%) and anxiety in 2 (33%), respectively. The results of laboratory examination were normal and the outcomes of treatment were good.</p><p><b>CONCLUSION</b>Juvenile primary FMS may not be a rare disease and the clinicians should pay more attention to it for avoiding misdiagnosis.</p>