Glossitis may be related to local conditions (infections, irritation) or be a sign of a systemic disease. Inflammation of the dorsal aspect of the tongue usually results in the loss of filiform papillae, i.e. atrophy (smooth tongue). The tongue may also have sores or be affected by various diseases of the oral mucosa . Cancer of the tongue is hardly ever encountered on the dorsal surface of the tongue. Leukoplakia and erythroplakia are an indication for a biopsy if they do not disappear within 2–3 weeks after the removal of potentially irritating factors.