Thermal imaging in acute herpes zoster or post-zoster neuralgia

Background/aims: Asymmetry of normal skin temperature patterns has been reported in patients with herpetic disorders. The aim of the study was to describe the temperature distribution in patients suffering from acute herpes zoster or post-herpetic neuralgia. Methods: Biographic data, including age, gender and time of onset of the skin lesions, were recorded. The distribution of pain was investigated by pain mapping, and the intensity of pain and dysesthesia was quantified by a visual analogue scale. Infrared thermal images of the affected body regions were performed in all possible views using either an Agema 870 or a NEC San-ei Thermotracer. Results: The mean temperature difference between the affected and the unaffected sides of the body in all patients was 0.52 +/-0.30 degreesC. Higher temperatures were detected in early cases with a disease duration of 1-9 days (mean temperature difference: 0.62 +/-0.36 degreesC) than in patients with pain scores greater than 79 (mean temperature difference: 0.48 +/-0.33 degreesC). Only 6 of 57 patients presented with a temperature difference between the affected side and contralateral side of less than 0.2 degreesC. Conclusion: Thermal asymmetry of the skin is a common finding in patients with acute herpes. However, the thermal patterns seem to correlate better with the duration of the disease than with the intensity of pain.