diagnosis of psoriasis - general principles

Last edited 08/2019

• based on the clinical features and usually presents no diagnostic difficulty

• only rarely is confirmatory biopsy required

• the distribution, colour and typical silvery scaling of the lesion in chronic plaque psoriasis are characteristic

• solitary lesions may occasionally be mistaken for epitheliomata; flexural involvement may be confused with intertrigo caused by candida

• scalp lesions may be mistaken for seborrhoeic dermatitis

• nail lesions result in deformity that resembles that caused by a fungal infection