Differential Diagnosis for Infection in the Corner of the Mouth
- Single Most Likely Diagnosis
- Angular cheilitis: This is the most common condition affecting the corners of the mouth, characterized by inflammation, redness, and sometimes infection. It is often caused by fungal (Candida) or bacterial infections, and can be exacerbated by factors such as vitamin deficiencies, dry mouth, or ill-fitting dentures.
- Other Likely Diagnoses
- Impetigo: A highly contagious bacterial skin infection that can occur around the mouth, including the corners. It presents with honey-colored crusts and can be itchy or painful.
- Herpes simplex virus (HSV) infection: Although more commonly associated with cold sores on the lips, HSV can also cause infections in the corner of the mouth, presenting with vesicles that rupture to form ulcers.
- Staphylococcal infection: Staphylococcus aureus can cause skin infections, including those in the corner of the mouth, which may present as abscesses, folliculitis, or impetigo.
- Do Not Miss Diagnoses
- Actinomycosis: A rare bacterial infection that can cause chronic abscesses or masses in the face and neck, including the corner of the mouth. It's crucial to consider this diagnosis due to its potential for extensive tissue destruction if left untreated.
- Tuberculosis (TB): Although rare, TB can manifest as a chronic infection in the corner of the mouth, especially in immunocompromised individuals. Missing this diagnosis could have severe consequences due to the potential for systemic spread.
- Sarcoidosis: An autoimmune disease that can cause granulomatous inflammation in various parts of the body, including the skin around the mouth. While not typically infectious, it's a critical diagnosis to consider due to its systemic implications.
- Rare Diagnoses
- Histoplasmosis: A fungal infection that can cause oral lesions, including in the corners of the mouth, particularly in immunocompromised patients.
- Blastomycosis: Another fungal infection that can manifest with oral lesions, including in the corner of the mouth, though it's more commonly associated with lung infection.
- Leishmaniasis: A parasitic infection that can cause skin lesions, which in rare cases might appear in the corner of the mouth, especially in travelers to endemic areas.