Periungual inflammation, also known as boil along the claw, is a purulent infection of the tissues around the nail caused by minor local injuries, starting with redness, swelling and severe pain on one side of the nail or at the nail root, and then gradually pus, which accumulates under the nail to form a subnail abscess, which is often chronic due to the lack of drainage of pus after it breaks down. Nail groin infection at the beginning of a side of the nail groove redness, swelling and pain, within a short period of time can be pus infection, can spread to the root of the nail and the opposite side of the nail groove, the formation of periungual inflammation, but also spread to the nail to form a subnail abscess. The two are still different, so how to check the two diseases on both beds? The following is an introduction to the examination items of periungitis and gray nail: examination of periungitis: bacteriological and fungal examination of secretions taken by swab. The examination of onychomycosis: sometimes the white blood cell count can be increased, X-ray examination has no positive findings.