Boswellic acids, the active compounds from Boswellia serrata (frankincense), are primarily known for their anti-inflammatory properties. There is some scientific rationale for their use in treating psoriasis, an inflammatory skin disorder. In vitro and animal studies have shown that boswellic acids can inhibit pro-inflammatory mediators such as 5-lipoxygenase (5-LOX), and may reduce cytokines like TNF-α and IL-1β, which are implicated in psoriasis pathogenesis.

However, clinical evidence specifically supporting the use of boswellic acids in psoriasis is limited. A small number of preliminary studies and case reports suggest potential benefit. For instance, a 2003 pilot study ("Topical Boswellic acids in the treatment of plaque psoriasis," Fitoterapia) found that a topical boswellic acid preparation led to improvement in psoriatic lesions in a small number of patients. However, this study was small and not rigorously designed. There are no large-scale, randomized controlled trials confirming efficacy and safety in humans for this indication. Most clinical evidence for boswellic acids pertains to other inflammatory diseases, such as osteoarthritis and inflammatory bowel disease.

In summary, while there is a plausible scientific mechanism and some early clinical data suggesting potential benefit, robust evidence for the use of boswellic acids in psoriasis is lacking. The evidence rating is therefore low, reflecting the need for larger, well-designed clinical trials.