I. Introduction

Complex regional pain syndrome (CRPS) is a very rare chronic painful condition involving the limbs. CRPS is described by other terms like causalgia, reflex sympathetic dystrophy (RSD), algodystrophy, post- traumatic dystrophy, Sudeck atrophy and shoulder-hand syndrome characterized by searing pain, hyperalgesia, allodynia,edema of the limb along with sudomotor, vasomotor, and skin changes. The case is being reported for its rarity and that it was diagnosed by careful history taking only (1).

II. PRESENTATION

53 year old male with no co morbidities for 1 year on medication presented with swelling, pain and stiffness of left ankle for 9 months. History of fracture of dorsum of right foot for which native treatment was taken, following which patient developed symptoms. No relevant family, personal history. CNS examination revealed shortening of right lower limb with decreased power and absence of ankle reflex. His MRI right ankle joint reveals mild effusion, mild marrow edema, mild peritendinous fluid along tibialis posterior and peroneus tendon, mild sprain like features.

III. COURSE AND MANAGEMENT

On further evaluation, the acute phase reactants, blood sugars and all other routine blood and urine tests were in normal limits. Tc 99 MDP-whole body three phase skeletal scintigraphy shows mild abnormal increased radiotracer distribution noted in small joints of right foot, abnormal increased Tc99- MDP uptake noted in periarticular surfaces of right ankle joint, inter tarsal, joints, tarsometatarsal joints and metatarsophalangeal joints with no evidence of abnormal increased 99Tc-MDP uptake noted in any other small and large joints of the body with Three phase bone scan findings suggestive of reflex sympathetic dystrophic features. Nerve conduction study shows peroneal neuropathy of right lower limb. Patient was started on NSAIDS, steroids and other supportive measures. Patient improved symptomatically on follow up.

IV. DISCUSSION

Complex Regional Pain Syndrome (CRPS) is a varying painful condition with pathognomonic features of regional pain that is disproportionate temporality and severity to the usual course of any known cause. The etiology of CRPS is not clear. It has an incidence of 5-6/100000/year, Mean Age 36-46 years, 78% of the cases are seen in women. In 58% cases, it occurs in the upper extremities, 42% in the lower extremities (2).

Type I CRPS is the most common. It often involves a limb without a direct nerve injury. CRPS Type II is recently alluded to as causalgia, includes a characterized apprehensive pathway and is related with an immediate nerve injury (2). Characteristic triad of symptoms comprises autonomic, sensory, motor features. Autonomic signs like Edema, Skin temperature changes, Skin color changes, Sweating, Nail and hair changes are commonly seen .Sensory features like burning ,aching throbbing, shooting, hyperalgesia and Motor change like weakness, distal tremors, dystonia can be noted. Differential diagnosis for complex regional pain syndrome include Neuropathic pain syndrome, Vascular Diseases, Cellulitis, Inflammation, Myofascial pain. Blood investigations do not play a major role in the diagnosis. Three- phase bone scintigraphy is highly sensitive and specific for CRPS while Plain radiographs and MRI have not been shown to be sensitive or specific for CRPS.

Treatment include drugs like steroids, vitamin c, alendronate, bretylium, ketansarin, phentolamine lidocaine, calcitonin, clonidine, baclofen. Early physical therapy is essential to avoid Edema, pain, atrophy and contractures (3). Psychological dysfunction is a reflection of the disease. Pain coping skills, Relaxation training, Cognitive behavioral therapy, Mirror therapy are the other treatments of choice.

V. CONCLUSION

Complex Regional Pain Syndrome is a chronic debilitating painful condition is presented for its rare incidence. Early diagnosis and management is essential to help patients and reduce suffering.

VI. References

Author(s) (2021) “Delayed Inhalational Injury due to Accidental Muriatic Acid Poisoning”, IARS’ International Research Journal. Victoria, Australia, 11(2), pp. 15–17. doi: 10.51611/iars.irj.v11i2.2021.161.

Herrick AL. Reflex sympathetic dystrophy (Complex regional pain syndrome type I). In: Rheumatology. Hochberg, Silman, Smolen, Weinblatt, Weisman, editors. 3rd ed. Mosby; 2003:725-32

Burns AWR, Parker DA, Coolican MRJ, Rajaratnam K. Complex regional pain syndrome complicating total knee arthroplasty. J Orthop Surg. 2006; 5:280– 283.

Rizzi R, Visenten M, Mazzetti G: Reflex sympathetic dystrophy. In: Benedietti C, Chapman CR, Morikcca G, editors. Recent advances in the management of pain. Advances in pain research and therapy, Volume 7. New York Raven press; 1984. p. 451– 465.