Does Repetitive Peripheral Nerve Blocks Vs Single Peripheral Nerve Block Vs Standard Medical Treatment Provide a Better Pain Relief on Zoster Pain at the Acute Phase and Reduce the Risk of Post Herpetic Neuralgia?

Study Model:

Randomized prospective registered After approval by the ethical committee of VinMec international Hospitals Institution , after approved registration prior to start the study to www.clinicaltrial.gov, 80 patients will be enrolled to participate to the study.

Inclusion criteria; Acute zona diagnosed by the dermatologist Acute skin rash with blisters in a limited area on one side of the body Eruption Unilateral On dermatome between C5 and S2 Age 18 to 85 years Old [YO], males and females American Society of Anesthesiologists score [ASA] grades I & II Patient who accepted to participate as volunteers and signed an informed consent

Exclusion criteria; Psychiatric disease Central nervous system disease or pre-existing neuropathy Coagulation abnormalities or anti-coagulant treatment (heparins Anti vit K anti thrombin) Contra indication to perform a peripheral nerve block or interfascial block Infection of the skin overlying the puncture site of the block Allergy to local anaesthetic or prednisolone Contra indication to prednisolone ASA III and IV Morbidity Obese BMI > 30 Pregnant woman Baseline evaluation; Date of first rash appeared Pain VAS score from 0 no Pain to 10 the worst imaginable pain Localization of the pain (Skin mapping of the painful area and allodynia area) Quality of life before the rash evaluated by the quality of Life questionnaire SF36 published with a certified translation in Vietnamese As soon as the diagnosis will be done by dermatologist the following treatment will be prescribed according to international published standards of Herpes; Oral administration of Acyclovir 800 mg 5 times a day for 7 days Oral administration of prednisolone except if contra indication 30mg twice daily on d1 > 7 15mg twice daily on d8 > 14 7.5mg twice daily on d15 > 21

Patient flow chart: