Differential Diagnosis for a 4-year-old Girl with Painful Urination
- Single most likely diagnosis:
- Urinary Tract Infection (UTI): The patient's symptoms of painful urination, frequent urination with small amounts, and the urinalysis results showing positive leukocyte esterase, positive nitrites, and the presence of white blood cells and red blood cells, along with a urine culture confirming 100,000 colonies of Escherichia coli, strongly support this diagnosis. The patient's history of recurrent cystitis also points towards a UTI.
- Other Likely diagnoses:
- Constipation with Urinary Retention: The patient's history of functional constipation and the presence of hard stool in the rectal vault could contribute to urinary retention, causing painful urination. However, the urinalysis and urine culture results suggest a UTI as the primary cause.
- Vaginitis: Although the genitalia are reported as normal, vaginitis could cause painful urination in a child. The absence of other symptoms like vaginal discharge makes this less likely but still a consideration.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Pyelonephritis: Although the patient does not have fever or back pain, pyelonephritis (an infection of the kidney) is a serious condition that can occur if a UTI is not properly treated. It's crucial to consider this, especially given the patient's history of recurrent UTIs.
- Obstructive Uropathy: Conditions like kidney stones or other obstructions could cause painful urination and are critical to diagnose early to prevent long-term damage.
- Rare diagnoses:
- Interstitial Cystitis: A condition causing bladder pressure, bladder pain, and sometimes pelvic pain. The symptoms can resemble those of a UTI, but the urinalysis and urine culture would typically be negative.
- Urethral Stricture or Other Anatomical Abnormalities: These could cause obstructive symptoms and painful urination but are less common and would likely require further diagnostic testing to identify.