My penis and body itches me all over... i've got small numbs over my penis.. it itches badly. i've had it for weeks now possible causes pls?

See below: Causes of generalized itching (aka “pruritis”) are too many to list. Pruritus can be a symptom of 1) a dermatologic condition such as an allergic response to something (chemical, medication, food); infestation (lice, crabs); atopic; or 2) an underlying systemic disease such as lymphoma, kidney, thyroid, and liver diseases, and diabetes. Recommend dermatologist if skin lesions present or a PCP.