| Mucosal pallor and atrophy | Anemia | Mucosal pallor; atrophic glossitis; candidiasis (including angular cheilitis); mucosal burning, pain, or tenderness; erythema | Oral mucosal pallor may be difficult to appreciate |
| Oral lesions (including ulcerative, erosive, or white lesions; swelling; erythema) | Lichen planus | Erosive: diffuse erythema and painful ulceration with peripheral radiating striae | In symptomatic patients, oral lesions may be treated with a topical corticosteroid gel or rinse |
| Reticular: white lacy striae, especially on bilateral buccal mucosa |
| Lupus erythematosus | Oral discoid lesions, honeycomb plaques, raised keratotic plaques, erythema, purpura, petechiae, irregularly shaped ulcers, cheilitis | In discoid lupus erythematosus, oral lesions seldom occur in the absence of skin lesions |
| Benign mucus membrane pemphigoid | Diffuse and painful oral ulceration, scarring | Intact blister formation occasionally may be seen intraorally (before rupture and ulceration) |
| Pemphigus vulgaris | Diffuse and painful oral ulceration, positive Nikolsky sign | Oral lesions often are the first manifestation of disease and may precede the onset of skin lesions |
| After initiating systemic therapy, oral lesions may take longer to resolve compared with extraoral lesions |
| Crohn disease | Diffuse mucosal swelling; cobblestone mucosa; localized mucogingivitis; deep linear ulceration; fibrous tissue tags, polyps, or nodules; pyostomatitis vegetans (“snail track” ulcers on an erythematous base); possible aphthous-like ulcers | Oral lesions usually resolve with systemic treatment of underlying intestinal disease, although persistent ulcers may require application of topical corticosteroids, and persistent swelling may respond to intralesional injection of triamcinolone acetonide (Kenalog) |
| Behçet syndrome | Recurrent, painful aphthous-like ulcers, usually numerous and especially involving the soft palate and oropharynx | Oral lesions are the most common lesions associated with Behçet syndrome and may be the first manifestation of disease |
| Change in mucosal pigmentation | Addison disease | Diffuse melanin pigmentation, candidiasis (in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome) | Differential diagnosis for diffuse oral melanin pigmentation also includes ethnic pigmentation, tobacco-related pigmentation, medication-related pigmentation, neurofibromatosis 1, McCune-Albright syndrome, and Peutz-Jeghers syndrome |
| Periodontal bleeding and inflammation | Diabetes mellitus | Gingivitis, periodontitis, candidiasis, generalized atrophy of the tongue papillae, taste dysfunction, salivary dysfunction, burning mouth syndrome, delayed wound healing | Patients with diabetes and associated periodontal disease may experience improved glycemic control with periodontal treatment |
| HIV-associated periodontal disease | Linear gingival erythema: linear band of erythema along the free gingival margin | In addition to these atypical forms of periodontal disease, patients with HIV also may exhibit more conventional forms of gingivitis and periodontitis |
| Necrotizing ulcerative gingivitis: ulceration and necrosis of gingival interdental papillae, gingival bleeding and pain, halitosis |
| Necrotizing ulcerative periodontitis: gingival ulceration, necrosis, rapid loss of periodontal attachment, edema, pain, spontaneous hemorrhage |
| Thrombocytopenia | Petechiae, purpura, ecchymosis, hemorrhagic bullae, hematomas | Hemorrhage may occur with minor trauma or spontaneously |
| Leukemia | Mucosal bleeding, ulceration, petechiae, and diffuse or localized gingival enlargement; secondary infections (e.g., candidiasis, herpes simplex virus infection, periodontal bone loss) | Gingival infiltration by leukemic cells occurs most often in acute monocytic leukemia and acute myelomonocytic leukemia |
| Dental erosion | Gastroesophageal reflux disease | Water brash, xerostomia, burning sensation, halitosis, palatal erythema, dental erosion | Dental erosion may require dental restorative treatment |
| Other oral findings usually will resolve with medical management of gastroesophageal reflex disease |
| Bulimia and anorexia | Dental erosion, xerostomia, increased caries rate, sialadenosis (especially bilateral parotid enlargement) | Dental erosion may require dental restorative treatment |
| Xerostomia and sialadenosis usually resolve on normalization of nutritional status; sialogogues may help |
