Tinea unguium

This code represents a fungal infection of the nails, commonly known as onychomycosis. It typically presents as discolored, thickened, and brittle nails, most often affecting the toenails but can also occur on fingernails. The infection is caused by dermatophytes, yeasts, or non-dermatophyte molds.

Use this code when documentation explicitly states a diagnosis of tinea unguium or onychomycosis confirmed by clinical examination or laboratory findings (e.g., KOH prep, fungal culture). This code is appropriate for both initial and subsequent encounters for this condition.

• Do not confuse with non-fungal nail dystrophies; ensure fungal etiology is documented.
• Consider additional codes for any associated complications or systemic conditions if present.
• Documentation should specify the affected nail(s) if relevant for treatment planning, though not required for this specific code.