There is a difference between psoriasis and papulosquamous syphilis rash. The difference between psoriasis and papulosquamous syphilis is mainly in terms of the infectiousness of the disease, the characteristic symptoms, and the extent of the disease attack. Psoriasis is a chronic recurrent skin disease with erythematous scales as the main symptom, and it is not contagious. Papulosquamous syphilis rash is mainly due to syphilis spirochete infection and caused by a chronic sexually transmitted diseases, can be directly or indirectly transmitted through the toiletries, infectious. Psoriasis usually presents with a rash that is markedly and intensely itchy, whereas papulosquamous syphilis causes a less itchy rash than psoriasis. In the early stage, papulosquamous syphilis only invades the skin and mucous membrane tissues, and in the late stage, it can involve all organs and systems of the body, especially the cardiovascular and nervous systems. Psoriasis, on the other hand, mainly attacks skin tissues and generally does not affect other body systems or tissues. If there are related symptoms, you should seek medical treatment in time to avoid delaying the condition. Pay attention to skin hygiene and care, quit smoking and drinking, and avoid overwork.