Pediatric complex regional pain syndrome: a review
Weissmann and Uziel Pediatric Rheumatology
Pediatric complex regional pain syndrome: a review
Rotem Weissmann 0 1
Yosef Uziel 0 1
0 Sackler School of Medicine, Tel Aviv University , Tel Aviv , Israel
1 Pediatric Rheumatology Unit, Department of Pediatrics, Meir Medical Center , 49 Tshernichovsky St., Kfar Saba 44281 , Israel
Complex regional pain syndrome (CRPS) is a chronic, intensified localized pain condition that can affect children and adolescents as well as adults, but is more common among adolescent girls. Symptoms include limb pain; allodynia; hyperalgesia; swelling and/or changes in skin color of the affected limb; dry, mottled skin; hyperhidrosis and trophic changes of the nails and hair. The exact mechanism of CRPS is unknown, although several different mechanisms have been suggested. The diagnosis is clinical, with the aid of the adult criteria for CRPS. Standard care consists of a multidisciplinary approach with the implementation of intensive physical therapy in conjunction with psychological counseling. Pharmacological treatments may aid in reducing pain in order to allow the patient to participate fully in intensive physiotherapy. The prognosis in pediatric CRPS is favorable.
Complex regional pain syndrome; Pediatric; CRPS; Pain amplification syndrome; Chronic pain
Background
Musculoskeletal pain is the most common reason for
referral to pediatric rheumatologists. Causes of
chronic musculoskeletal pain include a wide variety of
inflammatory or non-inflammatory conditions, such
as arthritis, hypermobility, fibromyalgia, growing
pains, complex regional pain syndrome (CRPS) and
more. Amplified musculoskeletal pain syndrome
(AMP) is a generic and descriptive term used to
describe chronic pain syndromes of unconfirmed
etiology, such as fibromyalgia and CRPS. In AMP, pain
signals are amplified, thus mildly painful or
nonpainful stimuli are registered by the body as very
painful, and this leads to a functional disability – as
the patient tries to avoid the induction of pain.
In this review we will focus on the condition of
pediatric chronic peripheral pain, more commonly
referred to as pediatric complex regional pain syndrome
(CRPS). Various nomenclature are used to describe this
condition, including complex regional pain syndrome
(CRPS), reflex sympathetic dystrophy, reflex
neurovascular dystrophy, causalgia, and localized idiopathic pain.
Matles was the first to describe a case of reflex
sympathetic dystrophy in a child [
1
].
CRPS is a condition of chronic peripheral pain, usually
of a distal extremity. This syndrome is characterized by
spontaneous or stimuli-induced pain, which is amplified
to a very high visual analog scale (VAS) score,
disproportionate to the actual incident trauma/stimulus, in the
presence of a wide variety of autonomic and motor
disturbances. CPRS is divided into two types. CRPS type I,
previously known as reflex sympathetic dystrophy,
usually develops after a preliminary event; usually minor a
trauma or fracture, without any significant nerve injury.
In contrast, CRPS type II, which is very rare in
childhood, previously named causalgia, is induced by partial
injury of a nerve or one of its major branches [
2
]. This
review summarizes the current information regarding
the epidemiology, etiology, diagnosis, treatment and
prognosis of pediatric CRPS.
Epidemiology
Among the pediatric population (children under 18 years
of age), CRPS type I is more common among girls. The
mean age at diagnosis is around 12 years of age. The
lower extremity is more commonly involved than the
upper, with some reports stating a predilection towards
involvement of the foot [
3–6
].
Information regarding the epidemiology of pediatric
CRPS type II is wanting. There are case reports of CRPS
type II among children as young as 3 years of age [
7–9
].
Currently, there are no data available regarding the
incidence of pediatric CRPS.
Etiology and pathogenesis
The specific causes of CRPS are unknown. There is a
general paucity of studies among the pediatric
population regarding the etiology and pathogenesis of CRPS,
although a variety of studies among adult patients
present interesting hypotheses. However, the
pathogenesis of pediatric CRPS is not necessarily identical to that
of adult CRPS.
Trauma
In many cases, CRPS follows a relatively minor trauma,
usually a sprain, twist, dislocation or soft tissue injury. In
some cases, no previous injury was recalled [
3–6, 10–13
].
Fractures are the precipitating event in about 5–14 % of
cases and surgical procedures in 10–15 % [14].
Psychological factors
Stress has an important role in inducing or perpetuating
CRPS. Cruz et al. found that children with CRPS showed
generally intact cognitive function. However, they
demonstrated an elevated risk of somatic symptoms and
emotional distress, especially anxiety [
15
]. These findings
correlate with those of Logan et al., who found that
children with CRPS reported greater functional disabilit (...truncated)