NEW YORK — Almost half of children with “growing pains” have not outgrown them 5 years later.
Those children who continued to have growing pains had significantly lower pain thresholds than did controls or patients whose pains had resolved, said Dr. Lisa F. Imundo, referring to recently published data by other investigators (J. Pediatr. 2010 [doi:10.1016/j.jpeds.2009.11.078
Chronic and idiopathic pain complaints are responsible for 7% of referrals to pediatric rheumatology centers, said Dr. Imundo, director of pediatric rheumatology at the Morgan Stanley Children's Hospital of New York–Presbyterian. Idiopathic pain syndromes in children include growing pains, benign hypermobility, reflex sympathetic dystrophy, fibromyalgia syndrome, chronic fatigue, chronic Lyme disease, and Munchausen and conversion disorders.
Growing pains are generally considered to be a temporary, benign condition that affects children aged 2-6 years. Affected children may wake up crying from a deep sleep, rubbing one or both legs. Episodes tend to occur only at night, when children may be awakened for several nights in a row, followed by days or weeks of uninterrupted sleep, explained Dr. Imundo.
To see what actually happens to children with growing pains as they age, investigators examined 35 of the 44 patients in the original cohort. At the time of the reevaluation, the mean age of the children was 13.4 years, and 51% (18 of 35) said they no longer had pain.
In all, 17 patients (49%) reported persistent growing pains. Of these, 14 patients currently had fewer pain episodes, compared with the time of their first diagnosis, whereas 3 patients said the pains were more frequent. Most (94%) of the persistent-pain patients had pain in the lower extremities, and about one-quarter had pain in the upper extremities. Pain was symmetric for 88% of this group. Nine children used analgesics regularly to relieve pain. None reported missing school because of pain.
One of the study's objectives was to determine whether children with growing pains develop other pain syndromes in adolescence. Of the 35 in the original growing-pain cohort, 5 children (14%) reported symptoms of other pain syndromes, such as migrainelike headaches (9%) or recurrent abdominal pain (6%). No patients developed arthritis or fibromyalgia.
Pain thresholds were assessed in predefined body areas using a Fischer-type dolorimeter. Pressure was gradually increased in increments of 1 kg/sec until the patient reported feeling pain. The threshold was measured in 18 predefined pressure points of fibromyalgia, 3 control points, and in the mid–anterior tibia where these patients commonly report pain.
Children with persistent pains had lower pain thresholds than did 38 age- and sex-matched controls (P less than .05) or patients with resolved growing pains (P less than .02). Such heightened pain sensitivity of children with continued growing pains was seen for the fibromyalgia points, the control points, and the tibia point (P less than .01 for each).
Dr. Imundo does not recommend opioids or NSAIDs for conditions that are associated with central pain-processing syndromes. Instead, she suggests that antidepressants or anticonvulsants may be more effective.
Disclosures: Dr. Imundo had nothing to disclose. This report contains information on the use of medications that are not approved for the use of growing pains.