Purpose: We have previously reported the physiological and biochemical effects of bath salts. In this study, we used bath additive containing artificial carbon dioxide and sodium chloride (S bath additive), and the acute effects of bathing once with S bath additive and chronic effects of daily bathing with S bath additive for 15 consecutive days were compared with the effects of bathing once in plain water. Improvement in 10 symptoms was investigated using a 5-point verbal rating scale (VRS). Methods: Nine patients aged 51-82 years (mean, 66.6 years) with cold intolerance and lower leg pain were treated with balneotherapy. Whole-body bathing at 40°C was performed for 10 min daily (day 1, bathing in plain water; days 2-16, bathing with S bath additive). On days 1, 2, and 16, changes in patient’s subjective symptoms were evaluated using a VRS ranging from -1 to +3. Results: Compared with bathing once in plain water, bathing once with S bath additive was improvement of coldness, body warmth, blood circulation promotion, limb warmth, lightness of foot, and coldness in limbs. Daily bathing with S bath additive for 15 days significantly improved all symptoms compared with bathing in plain water. A comparison between single and daily bathing with S bath additive showed that relieving fatigue and lumbago were significantly improved after consecutive bathing, demonstrating the benefits of long-term usage. Discussion: Bathing once with S bath additive had acute effects on symptoms associated with peripheral circulation, such as coldness in limbs, body warmth, and limb warmth. Daily bathing with S bath additive improved bone- and joint-related symptoms, such as lumbago and shoulder stiffness, demonstrating that the chronic effects of S bath additive differ from the acute ones. These results are consistent with previous studies on natural hot springs which found that the efficacy of short-term treatment was distinct from that obtained after >2 weeks of treatment.

A woman in her 80s developed a feeling of abnormal sensation in her face and excessive salivation. She was diagnosed with right facial nerve paralysis and was admitted to a local hospital. On admission, serum creatinine level was 0.54mg/dL and estimated glomerular filtration rate was 79mL/min/1.73m2. She was started on oral valacyclovir at a dose of 3,000mg/day to treat the right facial nerve paralysis. However, 5 days after starting oral administration, she developed generalized fatigue, vertigo, and vomiting. Serum creatinine level rose to 4.99mg/dL with mild disturbance of consciousness, so she was transported to our hospital on suspicion of acyclovir-induced encephalopathy. We performed hemodialysis for 3 consecutive days to remove the acyclovir from the circulation, which subsequently improved all her symptoms. She was later diagnosed with allergic tubulointerstitial nephritis based on renal biopsy.After discharge from our hospital, laboratory data showed a serum creatinine level of 0.67mg/dL. We later confirmed that the serum acyclovir level before the first hemodialysis session had been very high (11.9μg/mL).