The Effect of Light Emitting Diode on Acute Pain and the Inhibitory Effects of Postherpetic Neuralgia in Patients with Herpes Zoster

Jung, Se Won; Son, Hyun Ho; Lee, Young Seok; Lee, Sook Kyung

Abstract

BACKGROUND
Acute pain and postherpetic neuralgia often interfere with life quality severely. Light emitting diode (LED) has been proposed as one of the effective therapeutic tools for pain reduction. However, little has been published in the Korean medical literature about the effect of LED on acute pain and the inhibitory effects of postherpetic neuralgia (PHN) in patients with herpes zoster.
OBJECTIVE
The purpose of this study was to evaluate the efficacy of LED on acute pain and the inhibitory effects of PHN in patients with herpes zoster.
METHODS
Sixty patients who were hospitalized for herpes zoster were evaluated according to their age, sex, associated disease, nature of pain, interval between diagnosis, therapy, and PHN. The patients were randomly placed into either a LED group treated with I.V acyclovir, analgesics and LED or a control group treated with I.V acyclovir and analgesics alone. The severity of pain was evaluated by patients themselves using a visual analogue scale (VAS) and a verbal rating scale (VRS) at one week intervals. The occurrence of PHN was assessed at 4 weeks after the initial development of the characteristic skin lesion of herpes zoster.
RESULTS
The average days required for pain relief was significantly shorter in the LED group than the control group. The average weeks needed to reduce pain from 100 to 50 in the VAS, implicating relief of acute pain, were 1.4 weeks in the LED group and 1.8 weeks in the control group (p<0.05). The total number of patients reported to have experienced a drop in the amount of pain from 100 to 50 within a week was greater in the LED group (20 patients) than the control group (10 patients) (p<0.05). However, there was no difference in the onset of PHN between the two groups (p>0.05).
CONCLUSION
LED is an effective method which can be used to relieve acute herpes zoster pain quickly; however, LED cannot reduce the onset of PHN effectively.