Dermatological findings aid early detection of complex regional pain syndrome

By Will Boggs MD

NEW YORK (Reuters Health) - Dermatological findings can aid in the early detection of complex regional pain syndrome (CRPS), researchers from Canada report.

"All CRPS patients will eventually develop skin manifestations," Dr. Alain Brassard from University of Alberta in Edmonton told Reuters Health by email. "The early erythema may be so subtle that it may be unnoticed when there is a flare of the pain."

CRPS is typically a triphasic disorder with an early stage described as pain in a limb, with warm extremities that progressively cool, followed by atrophy as the condition worsens.

Dr. Brassard and Rameez Kabani describe a man in his 30s with chronic pain of the left arm who initially had a normal skin examination. During the visit, he developed gradual, mild erythema, accompanied by swelling and increased temperature of the left forearm.

A lengthy differential diagnosis had been excluded by previous examinations and imaging, according to the April 23 JAMA Dermatology online report.

Based on the dermatological observations in the context of his chronic pain, the authors diagnosed the patient as having CRPS with the erythema presenting secondary to neurologic stimulation.

A poorly understood disorder with unclear pathogenesis, CRPS is increasing in prevalence among adolescents and young adults. Women are affected three times more frequently than men, and the mean age at diagnosis is 42 years.

"Skin changes are common and often-critical features required for the diagnosis of CRPS," the authors say. "Edema and erythema were found in most patients, while dermatitis, erythematous papules, folliculitis, cutaneous atrophy, ulceration, and bullae were also seen to a lesser degree" among individuals in a retrospective medical chart review, published in the Journal of the American Academy of Dermatology in 2001.

"The purpose of this article was to make sure that the dermatology community is aware that early on, there may be erythema and with accentuation of pain on a limb may herald a CRPS diagnosis," Dr. Brassard said. "And if so, a prompt referral to a pain clinic should be done as stage 1 could be treated successfully."

Dr. Nader Nader from SUNY Buffalo and VA Western New York Healthcare System in Buffalo told Reuters Health by email, "Dermatologic findings often help to confirm the diagnosis, but other clinical indicators of CRPS should also be sought."

He added, "Skin findings can be highly variable. The degree of skin changes often seems to correlate with the severity of CRPS."

"Color and temperature changes over the skin surrounding the area in question are the most common encountered signs," Dr. Nader said. "Additionally, pilomotor reflex is exaggerated in CRPS and manifest by developing goose bumps without being cold due to autonomic dysfunction. There is a significant level of hyperalgesia and allodynia manifested as increased sensitivity toward touch and air in these patients."

Three of the four symptoms and three of the four signs that comprise the diagnostic criteria for CRPS proposed by the International Association for the Study of Pain involve skin changes.

SOURCE: http://bit.ly/1khRGT6

JAMA Dermatol 2014.

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