The Effects Of Cutaneous Nerve Block On Zoster Associated With Neuropathic Pain

Background: The herpes zoster patients have symptoms of overreactions to involved tissues and local immune inflammatory of the nerve. Pathologic damage occurred to nerve endings [1]. Acute herpes zoster pain depends on peripheral nerve endings and ganglion of the inflammatory response, and tissue injury, as well. The damaged skin biopsy also showed the damage of immune inflammatory response in early peripheral nerve. Pathological changes of peripheral nerve and nerve impulse conduction abnormalities, resulting in peripheral and central nervous system function, has a variety of pathological changes leading to postherpetic neuralgia persistent pain or various states of pain[2] [3]. Clinical observations shows that herpes zoster skin lesions of nerve block area can speed up the lesion area of scab and the healing process.Objective: Clinical evaluation in acute herpes zoster by nerve block is to be effective in inhibiting autoimmune peripheral nerve inflammation to control neurogenic pain caused by herpes zoster.Methods: 72 patients with herpes zoster, were randomly divided into 2 groups: cutaneous nerve block group (L group, n = 36), then the group was divided into 2 sub-groups: L1 group (n = 18, pathological lesions period) and the L2 group (n = 18, lesion healing); conservative treatment group (N group, n = 36), further divided into N1 group (n = 18, lesions period) and the N2 group (n = 18, lesion healing). L group received 0.3% lidocaine + adenosine mecobalamin 0.5mg + methylprednisolone 40mg, total 10-15ml, blocking the most severe skin lesions or pain in the most obvious areas of skin, from the nerve proximal to the distal. N group routine use of oral antiviral drugs, vitamin B12, analgesic drugs and for external use in the lesion area. Observation should includes two aspects: ? different treatments of herpes zoster skin lesions on the healing of skin lesions; ? involvement of different neural areas before and after different treatment, pain intensity and nature of change; ? changes in the nature of pain after treatment, VAS score level correlation with the incidence of PHN.Results:First, there is no significant difference in general conditions of patients, the scope of lesion, pain, and onset time before treatment (Table 1)Second, the effects of different treatments on healing of acute herpes zoster skin lesions Apply two methods of treatment during skin lesions in herpes zoster lesions. Compare lesion area scab time with pain relief (see Table 2). The two treatment times are around four weeks. Clinical observations are:1)Between the two treatment groups, there is no significant difference in times of rash occurred and receiving treatment (p> 0.05);2)Compare scab time in different lesion ranges:①Comparison of different treatment groups showed, averagely Group L1 was 3.5±1.4 days earlier than Group N1 in lesion scab. Compare groups of same lesion areas but different scab lesions times (P <0.05);②Comparison of different skin lesions showed that between Group L1 and Group N1, the smaller the lesion area, the earlier the scab, skin lesions range of <1% and> 2% were significantly different (P <0.05) ;③VAS pain score in different skin lesions between two groups and among each group showed that the smaller the lesion range, the more significant the pain relief (P <0.05).Third, compare the pain of neural regions involved before and after treatment among different groups (see Table 3,4,5,6)1, The nature of pain of nerves involved mostly are sustained burning pain, allodynia, hypoesthesia, and spontaneous pain.2, The effects on the nature of nerve pain before and after treatment with different methods①Comparison of before and after treatment showed significant difference (p <0.05).②The overall comparison of Group L and Group N: Group L showed significantly decreased ratio in continued burning, allodynia, and spontaneous pain after 4-week treatments (p <0.05), significantly increased ratio in hypoesthesia (p <0.05).3, The overall VAS pain score comparison between Group L and Group N showed that the pain was less severe in Group L, p <0.05, which was statistically significant.4, The effects on different periods of nerve pain in affected lesion area with different treatments①Group L1 and Group L2 : Group L1 showed significantly lower ratio of sustained burning than Group L2 (p <0.05) There is no significant difference in allodynia and hypoesthesia. Group L2 showed slightly increase in spontaneous pain, which is not statistically significant;②Group N1 and Group N2: Group N1 showed significantly decrease in continued burning and allodynia compared with Group N2 (p <0.05) There is no significant difference of hypoesthesia and spontaneous pain in both groups.5, The effect comparison of treatment involved between pathological lesion affected (Group N1 and L1) and the healing of skin lesions affected (Group N2 and L2): there is significant decreased percentage in continued burning and allodynia in Group N1 and L1 (p <0.05); there is no obvious increase of hypoesthesia in Group N1 and L1, but significantly reduced in spontaneous pain (p <0.05).Conclusion:1, Early block treatment of herpes zoster skin lesions can inhibit the immune inflammatory reaction zone, so as to accelerate the healing of local lesions scab;2, It can also significantly reduce the pain of herpes zoster affected area, and facilitate the change of pain type;3, The results of two treatments showed that the smaller the lesion area, the more significant the treatment4, The results also showed that early intervention in the treatment of herpes zoster skin lesions can be more effective in controlling pain.