Periodic acid-Schiff (PAS) staining for glycogen in clinically normal psoriatic and non-psoriatic skin.

PAS staining was used to assess the glycogen content of clinically normal forearm epidermis in 32 patients with active psoriasis, 30 patients with inactive psoriasis and 40 non-psoriatic subjects. Glycogen accumulation was greater in patients with active than in those with inactive psoriasis. The inactive psoriatics showed significantly less glycogen accumulation than the controls.