Differential Diagnoses for Strep Throat

When considering the differential diagnoses for strep throat, it's essential to categorize them based on their likelihood and potential impact on patient health. The following categorization helps in prioritizing diagnoses and ensuring that critical conditions are not overlooked.

• Single Most Likely Diagnosis

  • Viral pharyngitis: This is the most common cause of sore throat and often presents with similar symptoms to strep throat, such as throat pain, fever, and swollen lymph nodes. The justification for considering viral pharyngitis as the single most likely diagnosis lies in its high prevalence and the fact that most cases of sore throat are viral in nature.

• Other Likely Diagnoses

  • Infectious mononucleosis (mono): Caused by the Epstein-Barr virus, mono can present with sore throat, fever, and lymphadenopathy, similar to strep throat. The presence of fatigue, hepatosplenomegaly, and atypical lymphocytes on a blood smear can help differentiate it.
  • Acute tonsillitis: This condition can be caused by either viral or bacterial pathogens and presents with symptoms similar to strep throat, including severe throat pain and difficulty swallowing.
  • Laryngitis: Inflammation of the larynx can cause throat pain and hoarseness, sometimes mimicking the symptoms of strep throat.

• Do Not Miss Diagnoses

  • Epiglottitis: Although rare, epiglottitis is a medical emergency that can cause severe respiratory distress. It presents with sudden onset of severe sore throat, difficulty swallowing, and shortness of breath. The potential for airway obstruction makes it a critical diagnosis not to miss.
  • Lemierre's syndrome: A rare but serious condition characterized by a bacterial infection of the throat, followed by septic thrombophlebitis of the internal jugular vein. It can present with severe sore throat, fever, and neck pain.
  • Diphtheria: A bacterial infection affecting the mucous membranes of the throat and nose. Though rare in areas with high vaccination coverage, it can cause severe respiratory illness and is a critical diagnosis not to miss due to its potential for high morbidity and mortality.

• Rare Diagnoses

  • Gonococcal pharyngitis: A sexually transmitted infection that can cause sore throat. It's rare but should be considered in individuals with high-risk sexual behavior.
  • Tuberculous pharyngitis: A rare form of tuberculosis that affects the pharynx, presenting with chronic sore throat, fever, and weight loss.
  • Syphilitic pharyngitis: A manifestation of secondary syphilis, which can cause sore throat among other systemic symptoms. It's rare and typically seen in individuals with untreated syphilis.