Both pemphigus foliaceus and pityriasis rosea present with flaky red, scaly patches, but the difference is significant. In terms of etiology, pemphigus foliaceus is a fungal infection with Malassezia furfur, while the cause of pityriasis rosea is not particularly clear, but is related to bacterial and viral infections. In clinical manifestation, pemphigus foliaceus manifests as brown or pale white patches with slight scaling on the surface. Pityriasis rosea manifests itself as a rose-red oval-shaped patch with a layer of bran-like scales on its surface, especially around the periphery, with no conscious symptoms such as pain or itching. In terms of examination, spores can be detected by fungal microscopy in patients with lichen planus, while pityriasis rosea has no abnormal findings of examination.