Psoriasis is an inflammatory skin disease with huge negative impact on the quality of life of
the patients, and has an overall prevalence of 2% to 3% in the general population. Plaques
psoriasis is the most common type of the disease and presents red, well demarcated, and
silvery plaques mainly localized in the umbilical and lumbosacral area as well as in the
elbows, knees, and scalp.
Currently, pharmacological treatments such as retinoids, corticosteroids, vitamin D analogs
and biologics remain the main options for most psoriasis patients. However, side effect and
high cost barred many ordinary psoriasis patients.
A Chinese medicine formula "Inflammatory skin disease formula (ISDF)" was prescribed by Prof.
Lin for many years and observed to be effective in relieving atopic dermatitis and psoriasis
patients' clinical manifestations.
In this study, subjects with psoriasis will be randomized into treatment group of "ISDF" or
placebo group for 12 weeks.