What is the difference between skin cancer and psoriasis

Skin cancer is a very harmful disease that will cause great trouble to the patient's life. With bad living habits, more and more patients are suffering from skin cancer. So what is the difference between skin cancer and psoriasis? Let's learn about it together.

Early skin cancer often manifests as erythematous or papular lesions that are slightly higher than the skin surface, often accompanied by scaly desquamation or crust formation on the surface. The symptoms are similar to benign skin diseases such as psoriasis, eczema, and inflammation. As the lesion develops further, some characteristic signs will appear, such as a shiny, translucent papular nodule with bleeding on the surface and telangiectasia. Or a scar-like fibrous plaque with a smooth surface, without obvious telangiectasia, ulcers, and protrusions. Or there are small black spots in the lesion that merge with each other.
The above characteristics of skin cancer are very similar to the symptoms of certain precancerous lesions such as solar keratosis and keratoacanthoma, and it is difficult to distinguish them. Solar keratosis has rough erythema that is higher than the skin surface, and the surface is covered with scales. After removing the scales, the erythema often has no obvious protrusion. This is very similar to the erythema-like papules with clear boundaries and slightly higher than the skin surface of squamous cell carcinoma in situ, but the scales and crusts of the latter are more obvious, and the lesions are more substantial. Keratoacanthoma often occurs in exposed areas to sunlight. Without any warning signs, smooth red nodules will quickly appear within 2 to 3 weeks. There is a keratin embolus in the center, and dilated capillaries can be seen at the edge of the nodule. The nodules of squamous cell carcinoma that is distinguished from it are not smooth, and the edges of the nodules are translucent.
Psoriasis is a common, chronic, and easily recurring inflammatory skin disease with characteristic skin lesions. Initially, it is an inflammatory red papule, about the size of a millet or mung bean, which gradually expands or merges into a brown-red plaque with clear boundaries, an inflammatory red halo around it, obvious basal infiltration, and multiple layers of dry gray-white or silver-white scales on the surface. Gently scrape off the surface scales, and gradually reveal a layer of light red, shiny, translucent film, which is called the film phenomenon. Scrape off the film again, and small bleeding spots will appear, which is called the punctate bleeding phenomenon. White scales, shiny film, and punctate bleeding are important features for diagnosing psoriasis, known as the triad.