• Oral candidiasis is only rarely confused with other oral conditions.
• Oral candidiasis is uncommon in people other than infants, denture wearers, and the elderly. Have an increased threshold for suspicion of other oral conditions in otherwise healthy individuals.
• In otherwise healthy people, candidiasis may be the first presentation of an undiagnosed risk factor, such as HIV infection, cancer, diabetes, anaemia, or haematinic deficiencies.
• Leukoplakia is defined as a white patch or plaque on the mucosa that cannot be rubbed off [Scully, 2004].
• It may be caused by chronic exposure to irritants (particularly tobacco), or chronic infection (particularly oral candidal infection).
• It is most commonly a benign condition, but may be premalignant.
• Biopsy of leukoplakia is required to distinguish benign lesions from premalignant lesions.
• Lichen planus is an inflammatory condition that affects 1–2% of adults, and is described as reticular or erosive.
• Reticular lichen planus is characterized by bilateral, asymptomatic, white, lacy, striations (or papules) on the posterior buccal mucosa. This form is easily identifiable and does not usually require further investigation.
• Erosive lichen planus manifests as zones of tender erythema and painful ulcers surrounded by white, radiating striae. It may require biopsy to rule out serious causes.
• Hairy tongue results from elongation of the filiform papillae on the dorsum of the tongue. It is associated with poor oral hygiene and overuse of mouthwashes.
• Erythema migrans (also known as geographic tongue or benign migratory glossitis) is an inflammatory disorder affecting 1–3% of the population, and is associated with atopic conditions and psoriasis. It is characterized by central erythema caused by atrophy of the filiform papillae, and surrounding (slightly elevated) white-yellow borders.

[Breathnach and Black, 2004; Scully, 2004; Gonsalves et al, 2007]