Differential Diagnosis for a 3-year-old with the Presented Symptoms
- Single most likely diagnosis:
- Streptococcal Pharyngitis: This is likely due to the presence of purulent tonsils (3+ to 3 1/2), which is a common finding in streptococcal infections. The absence of wheezing and the specific mention of purulent tonsils point towards a bacterial infection rather than a viral one. The low oxygen saturation (Sats at 93%-95%) could be related to the infection itself or to the vomiting, which might have led to dehydration or aspiration.
- Other Likely diagnoses:
- Viral Pharyngitis: Although the tonsils are described as purulent, which leans more towards a bacterial cause, viral pharyngitis cannot be ruled out without a throat culture or rapid streptococcal antigen test. Viral infections can also cause significant tonsillar enlargement and exudate.
- Infectious Mononucleosis (Mono): This condition, caused by Epstein-Barr virus, can present with sore throat, fever, and significantly enlarged tonsils, sometimes with exudate. However, it's less common in children as young as 3 years old.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Retropharyngeal Abscess: Although less likely, this condition is a medical emergency that requires prompt diagnosis and treatment. Symptoms can include sore throat, difficulty swallowing, and in severe cases, respiratory distress. The absence of labored breathing and specific mention of tonsillar size does not rule out this condition entirely.
- Epiglottitis: This is another emergency condition that, although rare in the era of widespread vaccination against Haemophilus influenzae type b (Hib), can still occur. It presents with severe sore throat, difficulty swallowing, and can lead to airway obstruction. The child's ability to breathe without labor suggests this might be less likely, but it cannot be dismissed without further evaluation.
- Rare diagnoses:
- Lemierre's Syndrome: A rare condition characterized by a bacterial infection of the tonsils followed by septic thrombophlebitis of the internal jugular vein. It's more common in adolescents and young adults but can occur in younger children. The presence of purulent tonsillitis and systemic symptoms like vomiting could potentially fit this diagnosis, although it's much less common.
- Kawasaki Disease: This condition can present with fever, rash, and other systemic symptoms, including potentially significant cervical lymphadenopathy and oral mucosal changes. While it's a diagnosis that requires consideration in children with unexplained fever and systemic symptoms, the specific findings of purulent tonsils and the clinical context provided make it less likely in this scenario.