LAUSR

Complex regional pain syndrome (CRPS) is a chronic pain disorder most often localized to 1 or more limbs, and is associated with dysfunctional motor, sensory and/or autonomic nervous systems. There exist many alternative names in the literature for CRPS; these include reflex sympathetic dystrophy, algodystrophy, algo-neurodystrophy, causalgia, Sudeck atrophy and, shoulder-hand syndrome.1 CRPS was initially described after injury as disproportionate symptoms in time or intensity to the usual course of symptoms.2 Mitchell et al have described this syndrome after gunshot injuries during the American civil war.3 Apart from trauma, numerous other associations or triggers exist for this syndrome. These include headache, psychosis/neurosis, operated intracranial tumors, seizure disorder, and use of antiepileptics, particularly phenobarbital.4 There are many published reports describing the association of this syndrome to phenobarbital in late 20th century, with a gradual decline in reports following decline in the use of this drug. The predominant difference between usual CRPS and phenobarbital-associated CRPS is the marked predilection for bilateral involvement, which often leads to a confusion with rheumatoid arthritis. Despite the potential to cause mental slowness, sedation and other side effects, phenobarbital is still used in developing countries like India due to its low cost. We describe a case of a young woman with CRPS due to phenobarbital use, who was initially wrongly diagnosed and treated for inflammatory arthritis. It is important to recognize this entity as it dramatically responds to reduction or stoppage of this drug. 2 | C A SE REPORT