Black piedra

This code represents black piedra, a superficial fungal infection of the hair shaft caused by Piedraia hortae. It is characterized by the formation of hard, dark, gritty nodules firmly attached to the hair, typically affecting scalp hair but can also occur on facial or body hair. The infection is generally asymptomatic and does not cause hair loss.

Use this code when documentation clearly identifies a diagnosis of black piedra. This diagnosis is typically made clinically by observing the characteristic nodules on the hair shaft, often confirmed by microscopic examination of hair samples showing ascospores and hyphae. It is important to differentiate from other hair shaft abnormalities.

• Ensure documentation specifies "black piedra" to distinguish from white piedra (coded elsewhere).
• This code is for the fungal infection itself, not for any associated symptoms or complications, which would be coded separately if present.
• Consider the patient's geographic location, as black piedra is more prevalent in tropical and subtropical regions.