What is the cause of ketonuria (ketones in urine) with dysuria (painful urination)?

From the Guidelines

Ketones in urine with dysuria are most likely caused by a urinary tract infection (UTI) complicated by mild ketosis, which may be due to dehydration, fasting, or diabetes, and requires prompt medical evaluation and treatment. The presence of ketones in urine, as discussed in the guidelines for laboratory analysis in the diagnosis and management of diabetes mellitus 1, suggests that the body is breaking down fat for energy, which can be a result of various factors including dehydration, fasting, or diabetes. Dysuria, or painful urination, is a central symptom in the diagnosis of UTI, with high specificity, especially in young women 2.

When evaluating the combination of ketones and dysuria, it is essential to consider the potential for a UTI, which can progress to more severe infections like kidney infections if left untreated. The guidelines for recurrent uncomplicated urinary tract infections in women 2 emphasize the importance of acute-onset symptoms, including dysuria, in diagnosing UTIs.

Given the potential risks, it is crucial to seek medical attention within 24-48 hours, increase fluid intake to at least 2-3 liters of water daily, and provide a urine sample for culture. While waiting for medical care, over-the-counter phenazopyridine (AZO) can temporarily relieve urinary pain at a dose of 100-200mg three times daily for no more than 2 days. For individuals with diabetes, it is vital to check blood glucose levels and follow the sick-day management plan, and for non-diabetics, ensuring adequate carbohydrate intake and hydration is necessary.

The treatment of UTIs typically involves antibiotics like nitrofurantoin, trimethoprim-sulfamethoxazole, or ciprofloxacin for 3-7 days, depending on the severity and patient factors. Prompt medical evaluation and appropriate treatment are essential to prevent complications and improve outcomes.

From the Research

Causes of Ketonuria with Dysuria

• Ketonuria, or the presence of ketones in the urine, can be caused by various factors, including diabetes mellitus, fasting, or a low-carbohydrate diet 3.
• Dysuria, or painful urination, is often caused by urinary tract infections (UTIs), which can be complicated by the presence of ketones in the urine 4, 5, 6, 7.
• The combination of ketonuria and dysuria can be indicative of an underlying condition such as diabetes mellitus, which can increase the risk of UTIs 3.
• Other possible causes of dysuria include sexually transmitted infections, bladder irritants, skin lesions, and chronic pain conditions 4, 7.
• A comprehensive history and physical examination, as well as laboratory tests such as urinalysis and urine culture, can help determine the cause of dysuria and ketonuria 5, 6, 7.

Diagnostic Approach

• A targeted history and physical examination can help identify the cause of dysuria and ketonuria 4, 5, 7.
• Urinalysis and urine culture can help confirm the presence of a UTI and identify the causative organism 3, 4, 5, 6, 7.
• Further diagnostic evaluation, such as imaging studies, may be necessary in some cases to rule out other causes of dysuria and ketonuria 5, 6, 7.

Treatment and Management

• Treatment of UTIs typically involves antimicrobial therapy, although the choice of antibiotic may be complicated by antimicrobial resistance 3, 6.
• Management of ketonuria and dysuria may also involve addressing underlying conditions such as diabetes mellitus 3.
• Prevention of recurrent UTIs and ketonuria may involve antimicrobial-sparing approaches, such as behavioral modifications and dietary changes 6.