Polypodium species, particularly Polypodium leucotomos, have a history of traditional use in several cultures for various skin conditions, including rashes and hives (urticaria). Ethnobotanical records indicate that extracts from Polypodium rhizomes have been used in folk medicine, especially in South America and parts of Europe, for skin protection and to alleviate inflammatory skin reactions. However, the primary traditional uses documented are for conditions such as psoriasis, eczema, and general skin inflammation, rather than specifically for acute rashes or hives. Scientific studies on Polypodium leucotomos have focused mostly on its photoprotective and anti-inflammatory effects, with some evidence suggesting it may reduce symptoms of certain chronic skin disorders. Its antioxidant and immunomodulatory properties may theoretically contribute to skin barrier support and reduced inflammation. Nonetheless, high-quality clinical trials directly examining its efficacy for acute rashes or hives are lacking. The available traditional use and some mechanistic rationale provide a modest basis for its use, but the evidence is limited and not robust. Therefore, Polypodium’s use for rashes and hives is primarily justified by tradition, with a low but present level of supporting evidence.