Factors influencing the duration of treatment of acute herpetic pain with sympathetic nerve block: importance of severity of herpes zoster assessed by the maximum antibody titers to varicella-zoster virus in otherwise healthy patients.

Antibody responses to varicella-zoster virus (VZV) were serially investigated by the complement-fixation test in 72 Japanese of both sexes, suffering from herpes zoster (HZ), but otherwise healthy. Our objective was to elucidate whether there were mutual relationships among severities of skin lesion, maximum antibody titers to VZV, and duration of treatment for acute herpetic pain (AHP). Patients were divided into 3 groups: mild group (n = 26), moderate group (n = 26) and severe group (n = 20), according to the severity of the skin lesions. The 3 groups did not differ significantly with respect to age (P greater than 0.6). All patients were treated with regional sympathetic nerve blocks (SNBs) until pain relief was achieved. The durations of treatment for AHP became significantly longer as HZ increased in severity; the mean log10 durations of treatment (+/- S.E.) for the mild, moderate, and severe groups were 1.383 +/- 0.037, 1.616 +/- 0.055, and 1.888 +/- 0.069 days, respectively (P less than 0.01 for the mild group vs. the moderate group, and P less than 0.001 for the moderate group vs. the severe group). Irrespective of age, the maximum antibody titers closely paralleled the severities of the skin lesion of HZ; the mean maximum log2 antibody titers (+/- S.E.) for the mild, moderate, and severe groups were 5.12 +/- 0.24, 6.73 +/- 0.20, and 8.00 +/- 0.18, respectively (P less than 0.001 for the mild group vs. the moderate group and for the moderate group vs. the severe group).(ABSTRACT TRUNCATED AT 250 WORDS)

T-lymphocyte subsets in otherwise healthy patients with herpes zoster and relationships to the duration of acute herpetic pain.

T-lymphocyte subsets (CD3, CD4, and CD8 lymphocytes) in peripheral blood, parameters of cell-mediated immunity, were serially measured in 62 otherwise healthy Japanese patients with herpes zoster (HZ), and the findings were compared with those of 20 age-matched healthy controls who had had varicella but not HZ. Our objective was to elucidate whether there were changes in cell-mediated immunity, even in immunocompetent patients with HZ, and to investigate relationships between these variables and the duration of acute herpetic pain (AHP). All the patients underwent repeated sympathetic nerve blocks until pain was relieved. As compared with controls, there were slight increases in the percentages of CD4 lymphocytes (helper/inducer) and highly significant increases in the percentages of CD8 lymphocytes (suppressor/cytotoxic), resulting in marked decreases in CD4/CD8 ratios in the acute phase of HZ. The percentages of CD3 lymphocytes (pan-T lymphocytes) did not differ significantly. The duration of AHP was analyzed in 49 patients in whom T-lymphocyte subsets were measured more than twice. There was a weak but statistically significant positive linear correlation between age and the duration of AHP (r = 0.43, P < 0.01). There were statistically highly significant positive linear correlations between the number of days on which percentages of CD3 (r = 0.72, P < 10(-8)) and CD4 lymphocytes (r = 0.60, P < 10(-5)), and CD4/CD8 ratios (r = 0.62, P < 10(-5)) reached the maximum values after the onset of HZ and the duration of AHP. These correlation coefficients were higher than that between age and the duration of AHP.(ABSTRACT TRUNCATED AT 250 WORDS)

Severity of skin lesions of herpes zoster at the worst phase rather than age and involved region most influences the duration of acute herpetic pain.

Duration of acute herpetic pain (AHP) in 1431 patients for whom treatment was begun within 14 days after the onset of herpes zoster (HZ) was analyzed with respect to age, involved region, and severity of skin lesions. All patients were treated with repeated sympathetic nerve blocks until their pain was almost nil. Severity of the skin lesions at the worst phase was defined as mild when they covered less than one-quarter of the primary dermatome, as severe when they covered more than three-quarters of the primary dermatome, and moderate if they were between mild and severe. Without taking into account the severity of skin lesions, the duration of AHP for those aged 60 years or over and for those with trigeminal involvement was significantly longer than for patients aged under 40 years (P < 0.01 and P < 0.001) and for patients with thoracic (P < 0.001) and lumbosacral (P < 0.01) involvement, respectively. However, duration of AHP was significantly longer with increase in the severity of skin lesions in all age groups (the mild group versus the moderate group, P < 0.01 and P < 0.001; the moderate group versus the severe group, P < 0.01 and P < 0.001). The mean duration of AHP for patients aged 60 years or over with mild skin lesions ranged from 17.4 to 22.9 days, while that for patients aged 30-59 years with severe skin lesions ranged from 37.2 to 50.1 days. In addition, duration of AHP was significantly longer with increase in the severity of skin lesions in all regions (the mild group versus the moderate group, P < 0.01 and P < 0.001; the moderate group versus the severe group, P < 0.05 and P < 0.001). The mean duration of AHP for those with trigeminal involvement with mild skin lesions was 19.5 days, while the range was from 51.3 to 55.0 days for patients with severe skin lesions involving regions other than the trigeminal area. The frequency of severe skin lesions was significantly higher (P < 0.001) in patients aged 60 years or over and in those with trigeminal involvement. Multiple stepwise regression analysis revealed that the most important factors influencing the duration of AHP were the severity of skin lesions of HZ at the worst phase (r = 0.412), age (r = 0.277) and the involved region (r = -0.101). Thus, AHP in the elderly and in cases of trigeminal involvement is longer because of higher frequencies of severe HZ in the elderly and in trigeminal involvement rather than "being aged' and "trigeminal involvement' itself. We propose that one needs to analyze the results of treatment of AHP with respect to the severity of skin lesions at the worst phase.

Biphasic vasomotor reflex responses of the hand skin following intradermal injection of melittin into the forearm skin.

Melittin is the main toxin of honeybee venom. Previously, we have reported that intradermal injection of melittin into the volar aspect of forearm in humans produces a temporary pain and a subsequent sustained increase in the skin temperature due to axon reflex. To clarify the interaction between nociceptive inputs and vascular changes, we studied the influence of noxious stimulation by intradermal melittin on the vasomotor control of the distal extremities in human volunteers. Temperature changes of the bilateral palmar surface were recorded by means of a computer-assisted infrared thermography. Unexpectedly, we found a biphasic response of skin temperature. The skin temperature of both fingers and hands decreased immediately after the melittin injection and then increased well above the control level, prior to the injection. There was a considerable individual variation in the baseline skin temperature, prior to melittin. The skin temperature in a finger/hand with lower preinjection value increased more markedly in the second phase. Consequently, the individual variation in the peak temperature of the second phase was less pronounced. The initial decrease was interpreted as sympathetic vasoconstrictor reflex induced by noxious stimulation and the later increase as release of sympathetic vasomotor tone.

Optimum pain relief with continuous epidural infusion of local anesthetics shortens the duration of zoster-associated pain.

OBJECTIVE: To investigate effects of continuous epidural infusion (CEI) of 0.5% bupivacaine added to intermittent epidural boluses (IEB) on the duration of zoster-associated pain (ZAP), as compared with continuous infusion of normal saline placebo added to IEB. DESIGN: A prospective, double-blind, randomized, placebo-controlled study. SETTING: A university hospital and an affiliated clinic in Japan from 1996 through 1999. PATIENTS: 56 immunocompetent herpes zoster (HZ) patients, 50 years or older, within 10 days of rash onset and with severe pain and eruption. INTERVENTIONS: Patients were hospitalized and randomly allocated into 2 groups. CEI group given CEI of 0.5% bupivacaine (0.5-1.0 mL/h) plus IEB of 0.5% bupivacaine 4 times daily (n = 29). IEB group given normal saline infusion plus IEB of 0.5% bupivacaine 4 times daily (n = 27). All patients received oral acyclovir 800 mg, 5 times daily, for 7 days. OUTCOME MEASURES: The number of days required for complete cessation of ZAP and the proportion of subjects with allodynia beyond 30 days. RESULTS: The median time to cessation of ZAP was significantly shorter in the CEI group than in the IEB group (29 days vs. 40 days, P = 0.002). The number of patients whose allodynia persisted beyond 30 days of treatment was significantly lower in the CEI group than in the IEB group (10% vs. 37%, P = 0.027). CONCLUSIONS: CEI of 0.5% bupivacaine plus IEB was associated with a shorter duration of ZAP and fewer patients with allodynia beyond 30 days, compared with IEB plus normal saline infusion. Patients at high risk for developing postherpetic neuralgia (PHN) can be managed with intensive therapies at the early stage of disease, such as CEI, which maintains effective analgesia and may reduce the burden of PHN.