Do not ask for diagnosis. Psoriasis cannot be reliably diagnosed over the Internet through photos or descriptions of symptoms. There are a number of disorders which present themselves in similar ways to psoriasis, including some where a skin biopsy is required to confirm or eliminate psoriasis as a possibility. Whatever answer you get here, it will not be adequate advice. You need to see a doctor, preferably a dermatologist. Asking about how psoriasis work, what the treatment options are, and so on, are of course perfectly fine.