Phellodendron bark (from Phellodendron amurense, commonly called Amur cork tree) has a long history of use in traditional Chinese medicine (TCM) for various skin conditions, including psoriasis. In TCM, Phellodendron bark is known as "Huang Bai" and is considered to have "heat-clearing" and "dampness-drying" properties. It is often used in formulations aimed at relieving inflammation, itching, and redness associated with skin disorders. Historical texts and TCM practitioners have recommended it for conditions with symptoms similar to psoriasis, such as chronic dermatitis and eczema.

However, scientific validation for the use of Phellodendron bark specifically for psoriasis is limited. Some laboratory and animal studies indicate that compounds found in Phellodendron bark, such as berberine, exhibit anti-inflammatory and immunomodulatory effects, which could theoretically be beneficial for psoriasis. Nevertheless, robust clinical trials in humans with psoriasis are lacking. Most of the existing evidence comes from traditional use and anecdotal reports rather than well-designed scientific studies. Therefore, while Phellodendron bark is traditionally used for psoriasis and related skin issues, current scientific evidence supporting its efficacy for this specific condition is modest and not conclusive.