Pentacyclic triterpenoids, a class of phytochemicals found in many medicinal plants (such as betulinic acid, oleanolic acid, and ursolic acid), have been investigated for their anti-inflammatory, antioxidant, and wound-healing properties, which are relevant to the management of dermatitis. Scientific studies, primarily in vitro and in animal models, indicate that pentacyclic triterpenoids can modulate pathways involved in skin inflammation, such as inhibiting NF-κB activation and reducing the expression of pro-inflammatory cytokines (e.g., TNF-α, IL-1β).

Some specific triterpenoids, like glycyrrhetinic acid (from licorice root), have been formulated into topical creams and studied in small clinical trials for atopic dermatitis and other inflammatory skin conditions. These studies report improvements in symptoms like erythema and pruritus, attributed to anti-inflammatory and skin barrier-supporting actions. However, the clinical evidence is still limited in scale and quality, and most data come from preclinical research. There are also reports of traditional use of triterpenoid-rich plant extracts for skin conditions, but this is not as widely documented as the growing scientific literature.

In summary, while there is promising mechanistic and preclinical evidence, and some early clinical support for the use of pentacyclic triterpenoids in dermatitis, robust, large-scale clinical trials are still lacking. Thus, the evidence base is moderate, justifying a score of 3 out of 5.