A meta-analysis of combined oral and topical herbal medicine treatment for atopic dermatitis, and a systematic review of herbal medicine combined with topical preparations for adult acne, have been reported.

The layers on which they act differ. The topical acts on that spot; the oral acts on the whole-body condition. So we often look at them together.

However, you do not necessarily have to do both. If the extent is small, there are cases where the topical alone is enough, so we discuss and decide after examination.