Differential Diagnosis for Acute Pharyngitis
Single Most Likely Diagnosis
- Viral Pharyngitis (ICD-10: J02.9) - This is the most common cause of acute pharyngitis, often resulting from viral infections such as the common cold or influenza. The justification for this diagnosis is based on the high prevalence of viral infections in the community and the typical presentation of acute pharyngitis with symptoms like sore throat, fever, and cough.
Other Likely Diagnoses
- Streptococcal Pharyngitis (ICD-10: J02.0) - Caused by Group A beta-hemolytic streptococcus, this condition is a significant concern due to its potential complications, such as rheumatic fever. The rationale for including this diagnosis is the need to differentiate it from viral pharyngitis due to its specific treatment requirements (antibiotics) and potential sequelae.
- Infectious Mononucleosis (ICD-10: B27.0) - Caused by Epstein-Barr virus, this condition can present with acute pharyngitis, fever, and lymphadenopathy. It's considered in the differential due to its distinct clinical features and the importance of diagnosing it to guide management and predict potential complications.
Do Not Miss Diagnoses
- Lemierre's Syndrome (ICD-10: A48.8) - A rare but potentially life-threatening condition characterized by acute pharyngitis followed by septic thrombophlebitis of the internal jugular vein. The justification for including this in the "do not miss" category is its high mortality rate if not promptly diagnosed and treated with antibiotics.
- Epiglottitis (ICD-10: J05.0) - An acute inflammation of the epiglottis that can lead to airway obstruction. It's a medical emergency and must be considered in the differential diagnosis of acute pharyngitis, especially in adults, due to its potential for fatal outcomes if not immediately addressed.
Rare Diagnoses
- Diphtheria (ICD-10: A36.0) - A bacterial infection caused by Corynebacterium diphtheriae, characterized by a membrane covering the tonsils and pharynx. Although rare in areas with high vaccination coverage, it remains a consideration in unvaccinated individuals or those traveling from areas where diphtheria is endemic.
- Gonococcal Pharyngitis (ICD-10: A54.8) - Caused by Neisseria gonorrhoeae, this condition is seen in individuals with a history of oral-genital sexual contact. It's included in the rare diagnoses due to its specific risk factors and the need for targeted antibiotic treatment.