Lichen planus (LP for short) is one of the itchiest skin conditions known to man.  It typically shows up as small (about 1/4 - 1/2 inch) purplish bumps on the skin that itch like crazy. The most common areas to get it are on the wrists and/or shins, although it is possible to have it on any part of the body. Anyone can get it at any age.  Once you get it, it may last a few months and go away without treatment or it may last for years.  

It is usually diagnosed by a dermatologist doing a skin biopsy, which entails taking a tiny little sample from the skin and sending it to the lab, but in some cases a dermatologist can tell it is lichen planus without having to do a biopsy.

Treatment is usually with topical steroid creams, which help make it itch less, but usually don’t make it go away, and which can have side effect like thinning or discoloring the skin around the lichen planus.