Lichen oil, typically derived from species like Usnea barbata or other fruticose lichens, has a history of use in traditional and folk medicine, including as a topical remedy for skin complaints such as itching. Ethnobotanical records from Europe, Asia, and North America document the external use of lichen extracts and oils to soothe irritated skin, rashes, and minor wounds. The basis for this use likely stems from the presence of secondary metabolites in lichens, such as usnic acid, which are known to have mild antimicrobial and anti-inflammatory properties. However, these traditional applications are largely anecdotal and have not been systematically evaluated in controlled scientific studies for the specific indication of pruritus (itching).

Scientific literature offers minimal direct evidence supporting lichen oil’s efficacy in the treatment of itching. Most available studies focus on the antimicrobial properties of lichen extracts, and only a handful of in vitro or animal studies address potential anti-inflammatory effects. No robust clinical trials or systematic reviews have established a clear benefit of lichen oil for relieving itching in humans. As such, while its use is grounded in tradition and there is a plausible mechanism of action related to its bioactive compounds, the overall evidence is weak and not considered scientifically validated at this time.