Several types of psoriasis can occur on people’s skin; by far the most common is plaque psoriasis, also called psoriasis vulgaris (vulgar being Latin for common).
The majority of psoriasis studies focus on patients with plaque psoriasis, but most therapies will work for all types of psoriasis to some extent, as described in Table 1. Some people may find they have overlapping forms or a type that may evolve from one form to another over time.
John’s comment:
After first being diagnosed with psoriasis some 20+ years ago, I later came to realize that when it appears on certain parts of the body it manifests in different ways. So when I would get it in different places, sometimes I didn’t realize it was psoriasis until the dermatologist would say “yes, that is also psoriasis.”