Complex Regional Pain Syndrome following an Episode of Herpes Zoster: A Case Report

INTRODUCTION: Complex regional pain syndrome (CRPS) is characterized by searing pain, hyperalgesia, edema, allodynia, and skin changes. CRPS may be difficult to diagnose and to treat given poorly understood mechanisms as well as its presentation of symptoms that may mimic common conditions such as joint stiffness in this condition as well as rheumatoid arthritis. CASE REPORT: A 71-year-old female presented to our clinic post shingles of the right upper extremity. We diagnosed her with CRPS based on the Budapest diagnostic criteria and the clinical findings of pain and decreased the range of motion along with edema, hypersensitivity, discoloration and allodynia of the right thumb and index finger. She was treated with vitamin C as well as gabapentin and physical therapy. The patient was unable to go consistently to physical therapy due to insurance limitations, and we found no clinical benefit of vitamin C in reducing her symptoms. She was lost to follow-up during her treatment but re-emerged at 21 months. At that time she reported, she was largely unchanged in regards to her right-hand symptoms but did believe the gabapentin was helpful and still continued to take 300 mg daily. CONCLUSION: This case report highlights the usefulness of the Budapest diagnostic criteria to make the diagnosis of CRPS when associated with shingles, which can cause long-term pain and mimic some findings. Prompt diagnosis is important, as recovery typically extends beyond 6 months; our patient still reported continued symptoms at 21 months post initial presentation. Our primary treatment plan was physical therapy, which she discontinued due to insurance limitations. We recommend that patients, physicians, and third-party payers work together to extend access to physical therapy. More investigation is warranted regarding symptomatic treatment, as we found limited clinical benefit of gabapentin and vitamin C.