In most cases, a psoriasis diagnosis is rather straightforward. Your doctor will perform a physical examination of your skin, scalp, and nails, and also take your medical history. If you have a family member with psoriasis, it’s important to share that with your doctor.
In rare cases, a psoriasis diagnosis may require a biopsy, where your doctor takes a small sample of skin to examine under a microscope so he or she can determine the exact type of psoriasis and rule out other disease possibilities.