Differential Diagnosis for a Single Pustule on the Tonsil
- Single Most Likely Diagnosis
- Tonsillar abscess or peritonsillar abscess: This is the most common cause of a single pustule on the tonsil, resulting from a bacterial infection, typically by Streptococcus pyogenes or Staphylococcus aureus.
- Other Likely Diagnoses
- Infectious mononucleosis (mono): Caused by Epstein-Barr virus, it can lead to tonsillar exudates or pustules, especially in adolescents and young adults.
- Streptococcal pharyngitis: Although it more commonly presents with bilateral tonsillar exudates, a single pustule can be seen, especially in the early stages of the infection.
- Vincent's angina: A rare form of acute necrotizing ulcerative gingivitis that can extend to the tonsils, causing pustules or ulcers.
- Do Not Miss Diagnoses
- Lemierre's syndrome: A rare but potentially life-threatening condition caused by Fusobacterium necrophorum, which can lead to a single pustule on the tonsil as an initial presentation, followed by severe complications like sepsis and jugular vein thrombosis.
- Diphtheria: Although rare in areas with high vaccination coverage, it can cause a single pustule or membrane on the tonsil and is a critical diagnosis not to miss due to its potential for severe respiratory and cardiac complications.
- Rare Diagnoses
- Tuberculosis: Can cause a single pustule or ulcer on the tonsil, especially in immunocompromised individuals or those from endemic areas.
- Histoplasmosis: A fungal infection that can cause oral lesions, including a single pustule on the tonsil, particularly in immunocompromised patients.
- Syphilis: Primary syphilis can manifest as a single painless ulcer or pustule on the tonsil, which is a rare but important diagnosis to consider, especially in sexually active individuals.