Tinea nigra

This code represents Tinea nigra, a superficial fungal infection of the stratum corneum, typically presenting as a solitary, irregular, non-scaly, dark brown to black macule or patch. It is caused by Hortaea werneckii (formerly Exophiala werneckii) and most commonly affects the palms or soles.

Assign this code when documentation confirms a diagnosis of Tinea nigra, often characterized by its distinctive hyperpigmented appearance and location. Microscopic examination (e.g., KOH preparation) revealing septate hyphae and budding cells can support the diagnosis.

• Differentiate from melanoma or junctional nevi, which may have similar appearances but require different diagnostic and coding approaches.
• Ensure documentation specifies "Tinea nigra" to avoid confusion with other tinea infections.
• This code is specific to the fungal infection itself; do not use for non-fungal hyperpigmentation.