Clinical, laboratory characteristics and growth outcomes of children with growing pains.

Growing pains (GP), a common and benign pain syndrome of unknown etiology, is characterized by bilateral recurrent leg pain in childhood. There are no standardized diagnostic criteria for GP, and the diagnosis is often made by exclusion. To identify clinical and laboratory features, we included patients < 12 years with GP at National Taiwan University Children's Hospital between April 2006 and April 2019 in a retrospective study. We also compared body weight and body height z-scores between diagnosis and up to 2 years post-diagnosis to determine if rapid growth was associated with GP. This cohort study included 268 patients with a mean age of 4.7 ± 2.2 years. The most common features of GP were bilateral leg pain, no limitation of activity, intermittent pain, normal physical examination, and being well physically. The average number of Walters' criteria fulfilled by the patients with GP was 6.7 ± 0.9. Elevated serum levels of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) were observed in 37.5% and 15.6% of patients, respectively. Symptomatic medications were used in 33% of patients. Our study indicates that ALP and LDH may be biomarkers associated with GP. There was no significant association between GP and rapid growth within 2 years of diagnosis.