Differential Diagnosis for 19-month-old Male with Fever and Complex Medical History
- Single most likely diagnosis:
- Urinary Tract Infection (UTI): Given the patient's history of congenital posterior urethral valves, chronic kidney disease (CKD), and recurrent multi-drug resistant organism (MDRO) UTIs, a UTI is the most likely cause of the fever. The absence of nitrates or leukocyte esterase in the urinalysis does not rule out a UTI, especially in the context of a complex urinary tract and possible MDRO infection which may not always present with typical urinalysis findings.
- Other Likely diagnoses:
- Sepsis: Although the chest X-ray does not show pneumonia, the patient's history of recurrent infections and CKD puts him at risk for sepsis, which could be due to a variety of sources including the urinary tract, even if the urinalysis is not typical.
- Viral illness: Given the age of the patient and the absence of specific findings pointing to a bacterial infection, a viral illness could be a cause of the fever.
- Do Not Miss diagnoses:
- Pyelonephritis or upper urinary tract infection: Despite the urinalysis results, an upper urinary tract infection could be present, especially in a patient with a history of urinary tract abnormalities and recurrent infections.
- Sepsis due to a non-urinary source: Although less likely given the patient's history, sepsis from another source (e.g., gastrointestinal, skin) should not be missed as it could be life-threatening.
- Peritonitis: If the patient is on peritoneal dialysis (not explicitly stated but possible given CKD), peritonitis is a critical diagnosis not to miss.
- Rare diagnoses:
- Tuberculosis (TB) of the urinary tract: Although rare, especially in this age group, TB could present with non-specific symptoms including fever and could be considered in a patient with recurrent infections and an atypical presentation.
- Fungal infection: In immunocompromised patients or those with complex medical histories, fungal infections can occur and might present with fever and non-specific symptoms.