Infections
- Chronic mucocutaneous candidiasis
- COVID-19
- Enterovirus infections
- Hand foot and mouth disease
- Herpangina
- Herpes simplex (cold sores)
- Herpes zoster (shingles)
- Kawasaki disease
- Measles
- Oral candidiasis (thrush)
- Oral hairy leukoplakia
- Scarlet fever (scarlatina)
Non-infectious conditions
- Aphthous ulcers
- Behcet disease
- Black hairy tongue
- Chronic ulcerative stomatitis
- Cicatricial pemphigoid
- Denture stomatitis
- Erosive lichen planus
- Erythema multiforme
- Fissured tongue
- Geographic tongue (benign migratory glossitis)
- Hairy tongue
- Lichen planus
- Linear IgA bullous dermatosis
- Macroglossia
- Nicotine stomatitis
- Oral cancer
- Oral dysaesthesia
- Oral irritated fibroma
- Oral leukoplakia
- Oral lichenoid drug eruption
- Oral lichen planus
- Paraneoplastic pemphigus
- Pemphigus vulgaris
- Pyodermatitis–pyostomatitis vegetans
- Stevens–Johnson syndrome / toxic epidermal necrolysis (TEN)
- Stomatitis
- Transient lingual papillitis
- White sponge naevus