A case of rheumatoid arthritis presenting with postherpetic neuralgia and abdominal-wall pseudohernia

Postherpetic neuralgia is a common complication, while the postherpetic abdominal-wall pseudohernia (AWP) is a quite rare complication of herpes zoster (HZ). We report a patient >45 years of age with a history of rheumatoid arthritis (RA) who presented with two chronic HZ complications. A 75-year-old woman was admitted with neuralgia following cutaneous herpes zoster 6 weeks before. She was on long-term glucocorticoid, antimalarial and non-steroidal anti-inflammatory treatment. Confluent ulcers began to fill with granulation tissue, crusts, scars and skin discoloration in the area of the left T12-L2 dermatomes and reducible, painless swelling of the left flank, 20 × 20 cm, without palpable defect in abdominal-wall. There were typical joint deformity and positive rheumatoid factor. On neurological examination superficial abdominal reflexes were diminished in the left side, with hypesthesia of the overlying skin. Needle electromyography revealed denervational changes limited to the left-side muscles (on affected dermatomes T12-L2). Thoracoabdominal CT did not reveal the presence of existing hernia. There was an abdominal distension, the left abdominal-wall was thinner than the right side. The patient was treated with an oral preparation containing benfotiamine and vitamins B6 and B12, carbamazepine, amitriptyline, gabapentin, and local lidocaine. Skin rash left with scarring and pigmentary changes and the abdominal-wall swelling resolved within 8 months, however, the pain still persisted. To our best knowledge, this is the first observation of RA-associated postherpetic AWP. This rare motor complication appears to be self-limited with a good prognosis for recovery, while postherpetic neuralgia may require a combination of treatments for adequate pain relief. Older age, female sex, greater rash and acute pain severity are considered as risk factors associated with severe postherpetic neuralgia. In addition, patients with RA, mainly those treated with oral corticosteroids, are also at increased risk of HZ complications.