A 53-year-old female visited our office for dermatopathy of 'the right side of the trunk'. For one week prior to the appearance of the lesions she was feeling pain and 'a strange, creeping sensation' over the affected area. The patient had a known history of rheumatoid arthritis for which she was receiving medications, namely, methotrexate 10 mg p.o. once weekly and prednisolone 5 mg p.o. once daily. Five months prior to her visit she had a hospitalisation due to exacerbation of rheumatoid arthritis manifested by arthritis and pulmonary involvement. Throughout her childhood she suffered from uncomplicated mumps, chickenpox and pertussis.

Figure 1

The cutaneous eruption at the time of presentation had a dermatomal distribution extending from her right upper abdominal quadrant to her back and consisted of small vesicles coalescing to form plump-reddish plaques (Figures 1 and 2). Lesions were extremely tender on palpation. Lung auscultation revealed bilateral crackles at the lower fields, which, according to previous medical reports, were first noticed at her previous hospitalisation.

Differential diagnosis
Herpes zoster, allergic contact dermatitis, pityriasis rosea, candida intertrigo, drug eruption, dermatitis artefacta.

Diagnosis
Herpes zoster. The morphology and distribution of the eruption as well as history and clinical course, all contribute to the diagnosis. Also the fact that the patient was immunosuppressed was taken into consideration in favour of this diagnosis.

Treatment
The patient received intravenous acyclovir 500 mg, 4 times per day, for 10 days. At the same time corticosteroids for rheumatoid arthritis were discontinued. Nimesulide 100 mg p.o twice daily and codeine phosphate 30 mg combined with paracetamol 500 mg p.o. every 8 hours were provided, to manage inflammation and acute pain of herpes zoster, respectively. After 10 days the patient was discharged from the hospital with her lesions in regression but still with neuralgia. One month after leaving hospital corticosteroids were restarted due to exacerbation of rheumatoid arthriris. Herpetic neuralgia resolved gradually over a 2 month period. Nimesulide and combined codeine-paracetamol were gradually reduced and discontinued when the pain stopped.

Teaching points

• Immunosuppression increases both the risk for herpes zoster infection-reactivation and the risk for complications from the disease. Thus, hospitalization and intravenous acyclovir administration should be considered for the compromised host.
• Recent data supports the distinction between acute herpetic neuralgia (within 30 days of rash onset), subacute herpetic neuralgia (30-120 days after rash onset), and chronic (postherpetic) neuralgia (defined as pain presenting at least 120 days after rash onset) [1,2]. Thus, neuralgia is considered as a continuum with fluctuations.
• Although adequate antiviral therapy inhibiting replication of varicella zoster virus, attenuates the severity of zoster (viral shedding is decreased, rash healing is hastened, and the severity of acute pain is reduced), still some patients with zoster experience prolonged pain [3]. In patients over 50 years, 20% continue to report pain six months after the onset of the rash despite treatment with acyclovir, valaciclovir or famciclovir.
  

  Figure 2

Reference List

1. Desmond RA, Weiss HL, Arani RB, Soong SJ, Wood MJ, Fiddian PA et al. Clinical applications for change-point analysis of herpes zoster pain. J Pain Symptom Manage 2002; 23(6):510-516.
2. Dworkin RH, Schmader KE. Treatment and prevention of postherpetic neuralgia. Clin Infect Dis 2003; 36(7):877-882.
3. Schmader KE. Epidemiology and impact on quality of life of postherpetic neuralgia and painful diabetic neuropathy. Clin J Pain 2002; 18(6):350-354.

Acknowledgements

1. This case was prepared for our website by P. I. Vergidis, MD.
2. We thank Dr. G. Peppas for his contribution in the management of the case.