Out of more than 3,000 skin diseases, how do you know what condition you have? These 23 skin rash pictures and expert tips ...

A close-up of Pityriasis Rosea, a common skin condition characterized by a red, scaly, circular rash. This initial "herald patch" often appears before smaller lesions spread across the body.

Lyme disease can be diagnosed by the rash alone, new advice for the NHS says. People with the "bull's eye" circular rash do not need a blood test and should be treated immediately to avoid ...