Complex regional pain syndrome following viper-bite.

BACKGROUND

Complex regional pain syndrome (CRPS) may occur following fractures, surgery or different trauma. Development of CRPS following snake-bite has only been published in three reports (from Turkey, Nepal and Korea), although snake bites occur frequently world-wide. There has been no report from Western Europe. Vipera Berus is a common snake in European countries and the only venomous snake in Norway. We here describe the development of CRPS in a young woman as a consequence of a viper bite (Vipera Berus) in the right arm.

METHODS

We performed a clinical investigation (inspection, measurement of skin temperatures, sensory and motor evaluation) of the patient six months following the viper-bite, measurement of thermal thresholds (quantitative sensory testing, QST), measurement of resting sweat output (RSO) and quantitative sudomotor axon reflex (QSART) from both arms.

RESULTS

The patient fulfilled the Budapest criteria for a CRPS-condition, with continuous pain and symptoms and findings of autonomic dysfunction. In addition, we found elevated thresholds of warmth and cold, evidence of an affection of afferent A-delta and C-fibres as well as an affection of the efferent sympathetic sudomotor C-fibres by QSART. An increased RSO-volume was in inverse relationship to the decreased QSART result.

CONCLUSION AND IMPLICATIONS: It is important to be aware of viper-bite as a possible eliciting event for CRPS for early diagnosis and treatment of a patient. As long-lasting pain and oedema are known complications, it is probable that CRPS after viper-bites previously may have been underdiagnosed. As many patients are unaware of being bit, viper bite should be considered in cases of unexplained sudden pain and swelling of a limb.