Journal of Pain Research (Oct 2023)
Analysis of the Risk Factors for Mechanical Allodynia in Herpetic Neuralgia: A Retrospective Cross-Sectional Study
Abstract
Gang Xu,1,2 Weiwei Gong,2,3 Shihong Dong,2 Guojiong Hu,2,4 Weizhen Tang,1 Hecheng Yu1 1Department of Rehabilitation Medicine, Affiliated Tenth People’s Hospital of Tongji University, Shanghai Tenth People’s Hospital, Shanghai, 200072, People’s Republic of China; 2Department of Rehabilitation Medicine, Tongji University School of Medicine, Shanghai, 200092, People’s Republic of China; 3Department of Rehabilitation Medicine, Shanghai First Rehabilitation Hospital, Shanghai, 200090, People’s Republic of China; 4Department of Rehabilitation Medicine, Affiliated Yangzhi Rehabilitation Hospital of Tongji University, Shanghai, 201619, People’s Republic of ChinaCorrespondence: Gang Xu, Department of Rehabilitation Medicine, Affiliated Tenth People’s Hospital of Tongji University, Shanghai Tenth People’s Hospital, Shanghai, 200072, People’s Republic of China, Tel +86 21-66306496, Fax +86 21-66301051, Email [email protected]: Mechanical allodynia is reportedly common during herpetic neuralgia. The purpose of this study was to establish a risk prediction model to predict the individual risk of allodynia in herpetic neuralgia.Methods: Three hundred and eighty-six patients with trunk herpetic neuralgia were divided into two regions, T2-5 and T6-11. The causality between allodynia and other factors was analyzed by a binary logistic regression model.Results: 42.2% of subjects had allodynia, 137 suffered from dynamic allodynia, and 110 with dynamic allodynia experienced local sweating. The following 5 items as predictors determined this model: local sweating (Odd Ratio = 27.57, P< 0.001), lesion location (Odd Ratio=2.46, P =0.017), pain intensity (Odd Ratio=1.38, P =0.020), pain duration (Odd Ratio=0.94, P =0.006), and local scars (Odd Ratio=0.07, P< 0.001). The presence and development of allodynia are associated with local sweating. The positive proportion of the Iodine-starch test between the T2-5 (50.0%) with the T6-11 (23.7%) had a statistically significant difference (χ2=5.36, P=0.021). 29.5% of patients at the T2-6 had obvious sweating, which was different from only sticky feelings at the T6-11 (70.5%, χ2=10.88, P=0.001). 19.2% of patients with residual scars and allodynia was significantly lower than 48.5% of patients without allodynia (χ2=15.28, P< 0.001).Conclusion: This analysis suggests that local sweating is a concomitant symptom in dynamic allodynia, which imply the sympathetic nerves innervating the sweat glands of the skin were also involved during herpetic neuralgia. This may assist in the evaluation of dynamic allodynia and prove the role of sympathetic nerve intervention for herpetic neuralgia.Keywords: herpetic neuralgia, mechanical dynamic allodynia, sweating, sympathetic nerves, peripheral sensitization
