Water-Filtered Infrared A Irradiation in Axial Spondyloarthritis: Heat for Lower Back Pain

The effect of serial locally applied wIRA (sl-wIRA) in patients with axial spondyloarthritis (axSpA) is described: time of onset and duration of pain reduction, changes in disease activity and functionality, and changes at the molecular level (cytokines). Seventy-one patients with axSpA receiving an inpatient 7-day multimodal rheumatologic complex therapy (MRCT) were randomized into two groups: 35 patients with standardized MRCT (control group = CG) and 36 patients (intervention group = IG) with additive serial sl-wIRA (2 irradiations/day, total of 12 applications) of the back region. In IG, a significant pain reduction compared to daily baseline values was observed on days 1, 2, and 6 and compared to CG. There was a significant improvement of the global health and functional parameters in IG, a significant reduction of disease activity, and a significant drop in TNF-α serum levels, also significantly different to CG. Levels of IL-1, -6, -10 remained unchanged. sl-wIRA, as part of an MRCT in axSpA patients, caused a significant pain decrease on days 2 and 6, allowing an analgesics reduction. Improvement in the general state of health was noted. Decreasing serum levels of TNF-α may explain, at the molecular level, the subjective pain relief.