Differential Diagnosis for Sores in the Corner of the Mouth

• Single Most Likely Diagnosis
  • Angular cheilitis: This condition is characterized by inflammation of the corners of the mouth, often due to fungal or bacterial infections, and can be exacerbated by factors such as vitamin deficiencies, dehydration, or mechanical factors like drooling or poorly fitting dentures. It's a common condition that matches the symptom description closely.
• Other Likely Diagnoses
  • Herpes simplex virus (HSV) infection: HSV can cause painful sores around the mouth, including the corners. The primary infection can be severe, and subsequent outbreaks are usually milder but can still cause significant discomfort.
  • Impetigo: A highly contagious bacterial skin infection that can cause sores or blisters around the mouth, including the corners. It's more common in children but can occur in adults as well.
  • Eczema (atopic dermatitis): This chronic skin condition can lead to itchy, inflamed skin, including around the mouth. Sores in the corner of the mouth could be a manifestation of eczema, especially if there's a history of atopic diseases.
• Do Not Miss Diagnoses
  • Oral cancer: Although less common, sores in the corner of the mouth that do not heal could be a sign of oral cancer. It's crucial to rule out this diagnosis, especially in individuals with risk factors such as tobacco use, alcohol consumption, or a history of radiation therapy to the head and neck.
  • Sjögren's syndrome: An autoimmune disorder that can cause dry mouth and skin, potentially leading to sores in the corners of the mouth. Missing this diagnosis could lead to delayed treatment of the underlying condition.
• Rare Diagnoses
  • Melkersson-Rosenthal syndrome: A rare neurological disorder characterized by recurrent, facial paralysis or weakness (similar to Bell's palsy), swelling of the face and lips (usually the upper lip), and the development of folds and furrows in the tongue (fissured tongue). It can also cause sores in the corners of the mouth.
  • Plummer-Vinson syndrome: A rare condition characterized by difficulty swallowing, iron-deficiency anemia, and formation of esophageal webs. It can also lead to sores in the mouth, including the corners, due to the associated nutritional deficiencies.