Sng is a common symptom of herpes zoster associated with postherpetic pain

Herpes zoster is a skin disorder with a lifetime prevalence of 30%. Sng reflects a somatosensory response to tissue acidosis and is proposed as a symptom in herpes zoster. However, its prevalence and clinical significance in herpes zoster remain unclear. We examined the prevalence and temporal pattern of sng, and its associations with pain and itch.

A total of 137 adults with acute-phase herpes zoster were consecutively enrolled. The primary outcome was the prevalence of sng at baseline and at weeks 2, 4, and 12. Secondary outcomes included numeric rating scale (NRS) scores for sng, pain, and itch, correlations among these symptoms, and the association of baseline sng with subsequent pain and itch.

At baseline, 49.6% of patients reported sng, rarely as an isolated symptom but usually with pain and itch. Of 105 sng(+) myotomes, 20 (19.05%), 15 (14.29%), 11 (10.48%), and 11 (10.48%) were located on the back, chest, head, and waist, respectively. Sng severity was strongly correlated with pain severity in affected myotomes (r = 0.6712, p < 0.0001), but not with itch severity (r = -0.0329, p = 0.7388). Both the prevalence and severity of sng decreased over time. Furthermore, baseline sng NRS was correlated with pain and itch at week 12 (r = 0.48, p < 0.01; r = 0.40, p = 0.02).

Sng is common in herpes zoster, typically coexisting with pain and affecting axial myotomes. Its severity declines over time but may be associated with persistent pain and itch.