Potassium iodide (KI), initially derived from seaweed in the early 19th century, is used for treating sporotrichosis in dermatological practice. KI has also been used to treat several noninfectious inflammatory skin diseases. However, the mechanisms underlying the improvement in such skin diseases remain unknown, and KI is not used widely. Thus, although KI is an old drug, physicians may not prescribe it frequently because they lack knowledge about it. Although KI is very inexpensive and causes few side effects, it has been superseded by new powerful and expensive drugs, such as biological agents. We applied 3% KI topically to areas of inflammation induced by SDS in mice. The levels of IL-1 and TNF-α gene expression were reduced, whereas that of IL-10 gene expression was increased. Small interfering RNA that was designed to reduce IL-10 gene expression levels was injected into the same mice, and the anti-inflammatory effects of KI were not observed. Thus, the pharmacologic action of KI is based on its anti-inflammatory effects caused by the increase in IL-10 levels. This information would increase dermatologists’ awareness of KI as an efficacious and cost-effective treatment.

碘化钾（KI）最初源自19世纪初期的海藻，在皮肤病学实践中用于治疗孢子囊病。KI也已用于治疗几种非感染性炎症性皮肤病。然而，改善这种皮肤疾病的潜在机制仍是未知的，并且KI没有被广泛使用。因此，尽管KI是一种古老的药物，但医生可能不会经常开处方，因为他们缺乏有关KI的知识。尽管KI非常便宜并且几乎没有副作用，但是它已被功能强大且价格昂贵的新型药物（例如生物制剂）所取代。我们将3％KI局部应用于小鼠SDS诱发的炎症区域。水平的IL-1和TNF- α基因表达的减少，而其的IL-10基因表达增加。将旨在降低IL-10基因表达水平的小分子干扰RNA注入同一只小鼠中，未观察到KI的抗炎作用。因此，KI的药理作用是基于IL-10水平升高引起的抗炎作用。该信息将提高皮肤科医生对KI作为一种有效且具有成本效益的治疗方法的认识。