COMPLEX Regional Pain Syndrome type 1 (CRPS I), previously known as Reflex Sympathetic Dystrophy, is a heightened response of the sympathetic nervous system to a relatively minor injury. The hallmark of the disease is pain that is out of proportion to the degree of injury. The exact etiology of this disease remains unknown. Typical complaints of a CRPS patient include pain beyond the site of initial injury, allodynia, regional temperature disturbance, edema, sudomotor changes, and inability to use the affected extremity.1,2Unilateral skin color changes, hair and nail growth changes, and changes of skin texture of the affected extremity may be present.1,2
Early diagnosis and treatment may lead to full recovery, whereas a significant delay may result in a prolonged and even lifelong disability. For those unfamiliar with the characteristics of CRPS, diagnosis may be difficult. Because of the infrequency of presentation in a pediatric age group and also the limited communication abilities of children, diagnosis is often delayed.
Although a great deal of literature on CRPS has been published, most of it is geared to the diagnosis and treatment of adolescents and adults. Most published papers are case series of children older than 6 yr.3–11There is one case report of a 3-yr-old child who developed symptoms of CRPS type 2 (causalgia) after a sciatic nerve injury.12However, we could not locate any reports on CRPS type 1 diagnosis and treatment of very young children under the age of 5 yr.
We hope to promote awareness of this syndrome in very young children by discussing the presentation and successful management of a 3-yr-old child with CRPS type 1 who was evaluated and treated in our clinic.
A previously healthy 3-yr-old boy was referred to the University of Michigan Health System Multidisciplinary Pain Center for evaluation and treatment of persistent right foot pain presumed by his pediatrician to be secondary to CRPS I. His pain began 3 months earlier after a twist and fall injury to his right ankle. This resulted in mild ankle swelling, and the child complained of pain and difficulty with weight bearing. No fractures were found on radiography. After 3–4 weeks of ineffective conservative treatment consisting of rest, elevation, ice, and ibuprofen elixir, the patient was referred to orthopedic surgery for evaluation. His ankle and foot were placed in a cast for immobilization of the joint for 3 weeks. As a result, his weight bearing improved during this time. After the cast was removed, his ankle was splinted, and the boy reported more pain with weight bearing. On removal of the splint 2 weeks later, it was noted that edema had progressed to involve his ankle, foot, and distal leg. The affected area was extremely tender to touch and with movement. The patient’s mother also noted her son’s desire to keep the leg uncovered at night. The plain radiographs of the foot showed focal osteopenia, and magnetic resonance imaging revealed an effusion in the tibiotalar joint. In addition, the bone scan revealed soft tissue edema and was reported as “negative for CRPS.” Over the next few weeks before being seen in our clinic, the pain, swelling, and unwillingness to bear weight on the extremity persisted. The patient was evaluated by an infectious disease specialist who concluded that there was no evidence of generalized or local infection.
On presentation to our clinic, the patient appeared older than his stated age in size and maturity level. He was extremely anxious to undergo another evaluation. He was unable to describe his pain; however, he began to cry and guard his right leg when approached. He did not let his mother put a sock or shoe on his affected extremity. His right ankle, foot, and distal leg were edematous, warm, and extremely tender to touch. Light touch caused him to cry and pull away. Hair growth, skin color, and skin texture appeared normal. He did have full range of motion at the ankle, but he resisted weight bearing because of pain. His right foot was found to be 8°F warmer than his left. Based on his history and physical examination, the diagnosis of CRPS type 1 was established.
The child was started on naproxen elixir 125 mg orally twice a day. A transcutaneous electrical nerve stimulator unit was prescribed. The child was weary of the apparatus and electrodes at first. The mother had to play a crucial role in the initiation and maintenance of the transcutaneous electrical nerve stimulator treatment. After discussing the treatment plan, preparations were made for a spectacle with the mother playing the role of the patient. The electrodes were placed on her first, and she expressed extreme satisfaction during the stimulation. After seeing her, the son started asking for electrodes to be placed on him. The patient’s mother was instructed on proper electrode placement. She was also instructed on setting the proper stimulation intensity by placing two of the four electrodes on herself simultaneously with her son, and she therefore served as a gauge of stimulation during therapeutic sessions.
The patient also underwent physical therapy three times a week with a therapist interested in pediatric population. The emphasis was on desensitization with varying textures and increased weight-bearing activity. Physical therapy also included massage using lymphedema techniques of skin stretching, along with active and passive range of motion exercises. Two weeks later, his mother reported significant improvement. At 1-month reevaluation, his symptoms had completely resolved.
CRPS is a debilitating pain syndrome that appears to have no age boundaries. The theories of pathophysiology of this disease are abounding; nevertheless none can account for the full range of presentations. Most of the literature describing the diagnostic features and treatment is based on case reports on adult and adolescent patients. The diagnosis is uncommon in children, with most literature reporting patients primarily older then 6 yr.3–11We were not able to identify any reports of children younger than 5 yr presenting with CRPS type 1. Many clinicians have never encountered this disease, and when patients (especially children) present with this syndrome, other diagnoses are given and the appropriate treatment is delayed.3,5Early therapeutic intervention may result in complete recovery, whereas immobilization, often offered as an initial treatment, may promote the development of CRPS. Occasionally there is spontaneous resolution of the symptoms without formal treatment. However, for those cases that are progressive, delay in the initiation of treatment equals the worst prognosis.
The physical signs of CRPS in children are similar to those seen in adults. However, there are differences. Children appear to have a much higher incidence of lower extremity involvement as compared with adults.3,4Girls are more frequently affected than boys.3,5Diagnosis in very young children may be difficult because of their limited ability to describe their symptoms. A significant number of children do not report a history of trauma.3,6,8Caregivers should be questioned regarding behaviors such as limited use of the limb, sensitivity to light touch, or guarding of the extremity. Physical characteristics of the extremity since the onset of pain, such as changes of color, sweating, hair and nail growth, should be noted. Radiographic studies are often noncontributory as well. It is important to perform the evaluation of the extremity in a minimally threatening manner in hopes of limiting future anxiety and resistance to treatment. The examination should be performed with the caregiver present in the room.
Once the diagnosis of CRPS is made an age-appropriate treatment plan that provides adequate pain control along with encouragement of weight-bearing activity is essential. Consideration must be given to the fact that a very young child might not be receptive to traditional modalities of treatment. The approach might require modification according to the child’s level of understanding. Transcutaneous electrical nerve stimulator units have been shown to be beneficial in the management of CRPS with very young children.4,10,11In this case, the patient’s mother was used to introduce the unit to the child. Management should involve physical therapy, ideally with a pediatric physical therapist trained to treat CRPS. Desensitization, improvement of range of motion, and gradual introduction of age-appropriate weight-bearing activities are essential components for a successful treatment. Unless contraindicated, nonsteroidal antiinflammatory agents should be administered for the treatment of inflammation and pain. Additional medications, such as tricyclic antidepressants or gabapentin, may be added if the nonsteroidal antiinflammatory agents alone are not effective. More invasive procedures, such as sympathetic blockade, should be reserved for those patients who fail conservative management. In conclusion, primary care providers and specialists who treat young children should include CRPS in the differential diagnosis for persistent extremity pain. Early treatment gives children with CRPS the best chance of recovery.