Furuncle of left upper limb

This code describes a localized, painful, pus-filled inflammation of a hair follicle and surrounding tissue, specifically located on the patient's left upper extremity. It represents a bacterial infection, typically staphylococcal, that has progressed beyond a simple folliculitis.

This code is appropriate when documentation clearly indicates a diagnosis of a furuncle (boil) affecting any part of the left arm, including the shoulder, upper arm, elbow, forearm, wrist, or hand. Supporting documentation should specify the left side and confirm the nature of the lesion as a furuncle.

• Ensure the documentation specifies "left upper limb" to avoid laterality errors.
• Distinguish from carbuncles (L02.41-) which involve multiple interconnected furuncles.
• Do not use for abscesses without clear documentation of a furuncle as the origin.