About Psoriasis: Making the Diagnosis
There is no laboratory test for psoriasis. A doctor should have no problem recognizing this common disease from the type and location of the inflammation. There are, however, many diseases that can be confused with psoriasis: seborrheic dermatitis, eczema, lupus, syphilis, and some types of skin cancer, to name a few. An examination by a doctor will be needed to eliminate these possibilities.