Pediatric Complex Regional Pain Syndrome - An Overview

Introduction.

Chronic pain in any part of the body affects the individual's quality of life. Complex regional pain syndrome is one such condition. The presence of debilitating diseases in children makes it worse, as it strikes at an age when children are supposed to lead an active life filled with fun and frolic.

What Is Complex Regional Pain Syndrome?

Complex regional pain syndrome is a condition that affects the limb by causing chronic, persistent pain. The pain is quite intense and affects children's quality of life. Reflex sympathetic dystrophy is another term for complex regional pain syndrome. Complex regional pain syndrome occurs around twelve and is more common in girls. The syndrome affects the lower extremities more often than the upper extremities.

What Causes Pediatric Complex Regional Pain Syndrome?

The exact cause of pediatric complex regional pain syndrome is not known. Several studies have shown that certain factors could be the probable cause. The factors contributing to the onset of complex regional pain syndrome may differ from child to child. Some likely causative factors are as follows:

• Tissue Injury - Injury to the soft tissues or the bone following a sprain, tear, fracture, or even post-surgery can cause damage and may subsequently cause complex regional pain syndrome.

• Stress and Anxiety - Children who experience stress and anxiety due to school pressure, an unhappy family environment, or being victims of child abuse were shown to be prone to complex regional pain syndrome.

• Abnormal Immune System - Studies showed that when blood was tested in children with pediatric complex regional pain syndrome, an increase in cytokines and interleukins was found, suggesting an immune system abnormality.

• Abnormal Nervous System - Pain signals usually travel to the brain from the injury site through the spinal cord. Damage to these pain signals can produce abnormal movements and cause pediatric complex regional pain syndrome.

• Genetics - Studies showed that children with human leukocyte antigen from the mother were at an increased risk of developing complex regional pain syndrome.

What Are the Symptoms of Pediatric Complex Regional Pain Syndrome?

Pediatric complex regional pain syndrome can affect either limb (arm, leg, hand, or foot), although it is more common in the lower extremities, such as the feet. Some of the most common symptoms of pediatric complex pain syndrome are as follows:

• Severe Prolonged Pain - When moving the limb, add weight to the affected limb or even when the stem is at rest. The nature of the pain varies among children; some may experience sharp shooting pain, a stabbing sensation, a sensation of the affected limb being squeezed, or a pricking with pins sort of pain in the affected limb.

• Allodynia - A condition of increased skin sensitivity where the child experiences severe pain with a distinctive touch of the skin or even a drop in temperature can cause discomfort for some children.

• Change in the Skin of the Affected Limb - A change in skin color is observed on the affected limb. Some may experience a rise or drop in the temperature of the affected limb. The skin texture may be dry and scaly, whereas the presence of swelling makes the skin appear shiny. Changes in the growth of nails and hair patterns may also be observed on the affected limb.

• Abnormal Movement - Affected limb may have limited movement or face difficulty due to joint stiffness. A condition where the muscles contract involuntarily, causing tremors (dystonia), may be present in some children.

How to Diagnose Pediatric Complex Regional Pain Syndrome?

There are no specific tests to diagnose pediatric complex regional pain syndrome. A proper physical examination and medical and family histories may help with the diagnosis.

Pain in the limbs could be due to various other reasons (growth spurts in children) or other disease conditions like fibromyalgia or arthritis.

Other potential causes of similar symptoms are ruled out by doing blood tests (such as erythrocyte sedimentation rate (ESR) and antinuclear antibodies), magnetic resonance imaging (MRI) scans, and computed tomography scans (CT scans).

How to Treat Pediatric Complex Regional Pain Syndrome?

Pain relief must be the treatment goal. Pain management includes medications, physical therapy, and psychological therapy. The treatment varies depending on the severity of the condition.

• Medications - The use of non-steroidal anti-inflammatory drugs (for example, Ibuprofen) and anti-epileptic drugs (for example, Gabapentin) may be used to relieve pain and involuntary muscle tremors. Studies have shown that children experience pain relief through antidepressants (Amitriptyline) and anticonvulsants (Phenytoin).

• Physical Therapy - Physical therapy includes regular exercises, high-intensity exercises, and intense aerobic activities to improve circulation to the limb, which subsequently can reduce the stiffness and pain of the affected limb. Duration and intensity vary from child to child and do not significantly improve the conditions. Studies have shown that physical therapy, medications, or intense physical therapy alone can marginally improve the child's condition.

• Psychological Therapy - Psychological therapy is advised to help the child cope with pain and adapt relaxation techniques to help reduce the anxiety and stress experienced by the child. Occupational therapy may also be recommended to improve the child's fine motor skills (picking toys, throwing a ball). Desensitizing techniques such as rubbing lotion and playing with clay help improve the hypersensitive nature of the skin to the touch (allodynia).

• Invasive Therapy- Invasive therapies such as sympathetic nerve blocks and spinal cord stimulation may be used. Sympathetic nerve blocks involve injecting an anesthetic solution into the sympathetic nerve to interrupt the pain signals from the affected limb.

Spinal cord stimulation is an invasive therapy in which electrical impulses are delivered to the spinal cord using electrodes to help reduce pain and improve the function of the affected limb. Invasive treatments did enhance the functioning and pain of the affected limb; they also came with complications of bleeding and infections. Invasive therapies are rarely used in children for the same reason.

Conclusion

Unfortunately, pediatric complex regional pain syndrome is not a preventable disease condition. However, studies have shown that early intervention with exercises in conjunction with rehabilitation programs can improve the disease condition to a large extent. The primary objective of the treatment approaches is to enhance the child's quality of life.