How is hairy tongue (lingua villosa nigra) diagnosed?

Correct answer: D. Clinical examination — elongated brown-black projections on the dorsal tongue, associated with predisposing factors

• A. CT imaging has no role in diagnosing hairy tongue — it is a clinical diagnosis.
• B. Biopsy (showing filiform papilla hyperkeratosis) can confirm the histopathology but is NOT required for clinical diagnosis. The characteristic appearance is sufficient.
• C. Tongue swab culture may identify chromogenic bacteria or Candida but is not the standard diagnostic approach for hairy tongue.
• D. CORRECT. Hairy tongue is a CLINICAL diagnosis based on the characteristic appearance: elongated brown, black, green, or yellow hairy projections on the posterior dorsal tongue. No biopsy or special testing is required. A thorough history identifies predisposing factors (antibiotics, tobacco, poor oral hygiene, coffee/tea, xerostomia, hydrogen peroxide rinses).