Perianal venous thrombosis

This code describes a thrombosed external hemorrhoid, which is a blood clot that forms in a vein just under the skin around the anus. It typically presents as a painful, firm, bluish lump in the perianal region.

Use this code when documentation explicitly states perianal venous thrombosis, thrombosed external hemorrhoid, or an acute perianal hematoma. It is appropriate for both spontaneously resolving and surgically excised cases.

• Differentiate from internal hemorrhoids, which are coded differently even if thrombosed.
• Do not use for non-thrombosed external hemorrhoids (K64.3).
• Consider an additional code for any associated complications, such as ulceration or infection, if documented.