A study on the treatment of the acute phase of herpes zoster for prevention: A retrospective study of 140 cases treated during the last 3 years and 10 months

Abstract

【Background】 In the treatment of acute herpes zoster, several treatments have been widely used. However, some patients suffer from post-herpetic neuralgia, an intractable pain. No guidelines for the treatment of acute herpes zoster have been established. In this study, we evaluated the effects of analgesics and the timing of nerve blocks (NB) on the pain management of acute herpes zoster.
【Methods】We divided 140 cases into groups and retrospectively evaluated the effects of analgesics and the timing of interventions on the pain management of acute herpes zoster.
Study I : We divided 140 cases into 4 groups according to treatment: Group 1 (opioids, NB and analgesic adjuvant (AA), n= 58 ), Group 2 ( NB and AA, n= 38 ), Group 3 (opioids and AA, n= 21 ) and Group 4 (AA, n= 23 ).
Study II : We divided 140 cases into NB groups (Group 1 + Group 2 ) and non-NB groups (Group 3 +Group 4 ).
Study III : We divided 140 cases into opioid groups (Group 1 + Group 3 ) and non-opioid groups (Group 2 + Group 4 ). We further divided each group in Study I - III into 2 subgroups, early group (treatment before one month after onset) and late group (treatment after one month).
Study IV : To determine the effective timing of NB, we conducted a sensitivity analysis of 96 NB cases at different cutoff days ( 20 - 40 days) . In addition, in Study I - IV, we compared the VAS values at 3 months and 6 months after the onset between all groups.
To evaluate the rate of VAS reduction, we applied a logarithmic linear regression model ( Log ( VAS ) = β₀ + β₁ (months)) to each data set. We also conducted a sensitivity analysis to determine the optimal cutoff days.
【Results】All groups treated within 30 days after the onset exhibited lower VAS values at 6 months after the onset. The β₁ values of the early treatment groups ( 0.260 - 0.302 ) was higher than those of the late treatment groups ( 0.204 - 0.214 ), indicating that the treatment at the early phase decreases pain more quickly. Initiating NB within 3 0 days after the onset is optimal. Presumably, initiating NB within 34 days is acceptable.
【Conclusion】It is important to relieve severe pain early in the treatment of the acute herpes zoster. Our results suggest that initiating NB within 30 days after the onset and / or opioid therapy as soon as possible improve post-herpetic pain management.