🩺 Urinary Tract Infection (UTI) (OSCE focused)

Candidate Instructions:You are a final-year medical student in General Practice. A 28-year-old woman presents with urinary symptoms. Take a focused history, perform a relevant examination, and discuss your differential diagnoses and initial management plan. You are not required to perform an intimate examination.

🧬 Background

• Urinary tract infections (UTIs) are among the most common bacterial infections in adults.
• Caused in 70–90% cases by E. coli, followed by Klebsiella, Proteus, and Enterococcus.
• Women are at higher risk due to a shorter urethra, sexual activity, and pregnancy-related changes.
• Complications include pyelonephritis, sepsis, and recurrent UTIs.

Key History Points 📝

• ⏱️ Duration: Onset, frequency, progression.
• 🚽 Lower UTI symptoms: Dysuria, frequency, urgency, nocturia, suprapubic pain, haematuria.
• 🌡️ Systemic: Fever, rigors, flank pain, nausea/vomiting → pyelonephritis.
• 🧬 Past history: Childhood UTIs, recurrent infections, renal disease, structural abnormalities, catheter use.
• 💊 Drug history: Recent antibiotics, resistance, allergies.
• 👩 Women: Pregnancy, LMP, contraception, new partner (STI risk).
• 🧓 Elderly: Confusion, falls, incontinence, frailty.

Examination Focus 👀

• 🫀 Obs: Temp, HR, BP, SpO₂ (check for sepsis).
• 🫁 General: Pallor, hydration status, toxic appearance.
• 🩺 Abdomen: Suprapubic tenderness.
• 🧍 Renal angle tenderness: Suggests pyelonephritis.

Differentials ⚖️

• ✅ UTI: Cystitis, pyelonephritis.
• 🧬 STIs: Chlamydia, gonorrhoea, urethritis.
• 👩 Vaginitis: Candida, BV, trichomonas.
• 💎 Stones: Loin-to-groin pain, haematuria.
• 🚨 Other: Malignancy (persistent haematuria), interstitial cystitis.

Investigations 🔬

• 🧪 Urine dipstick: Nitrites, leukocytes, blood (useful in <50 yrs, but not reliable in elderly/pregnant).
• 🧫 MSU culture: Confirm pathogen, sensitivities.
• 🧪 Bloods: FBC, U&E, CRP if systemic unwell.
• 🫁 Pregnancy test: Always in women of childbearing age.
• 🧪 STI testing: If sexual history suggests risk.

💊 Management

🚨 Red Flags (Hospital Admission)

• Systemic features: rigors, fever >38°C, vomiting.
• Signs of sepsis or shock.
• Pregnant women with suspected pyelonephritis.
• Catheter-associated sepsis.
• Obstructed kidney (stone + infection = urological emergency).

Examiner’s Marking Guide 📋

• History covers LUTS + systemic + red flags.
• Examination: abdomen + renal angle + vitals.
• Considers key differentials (STIs, stones, gynae causes).
• Investigations: urine dip, MSU, pregnancy test, bloods if unwell.
• Safe management: empirical antibiotics, fluids, safety-netting.
• Special considerations: pregnancy, elderly, recurrent UTIs.

💡 Teaching Pearl: – Urosepsis should always be suspected if there is fever + hypotension + confusion. – Asymptomatic bacteriuria → only treat in pregnancy or before urological surgery. – Chronic/recurrent UTIs may need prophylaxis (e.g., nightly nitrofurantoin, post-coital antibiotics).

🧑‍⚕️ Case Examples - Urinary Tract Infections (UTI)

• Case 1 (Simple Cystitis in Young Woman): 🚺 A 22-year-old student presents with dysuria, urinary frequency, and suprapubic discomfort. She is afebrile, with no systemic features. Dipstick shows leukocytes and nitrites. Diagnosis: Uncomplicated cystitis. Teaching point: Treat empirically with 3 days of nitrofurantoin; no imaging needed if symptoms settle.
• Case 2 (Pyelonephritis): 🔥 A 35-year-old woman reports fever, rigors, vomiting, and left-sided flank pain. She has costovertebral angle tenderness. Bloods show leukocytosis and raised CRP; urine culture grows E. coli. Diagnosis: Acute pyelonephritis. Teaching point: Requires systemic antibiotics (often IV), IV fluids, and hospitalisation if septic or unable to tolerate PO therapy.
• Case 3 (Catheter-Associated UTI in Elderly): 🧓 An 81-year-old man in a care home with a long-term Foley catheter develops fever, acute confusion, and malodorous urine. Dipstick is not diagnostic; culture grows Klebsiella. Diagnosis: Catheter-associated UTI. Teaching point: Treat only if symptomatic, change the catheter, and give antibiotics guided by culture. Review ongoing catheter need.
• Case 4 (Pregnancy): 🤰 A 30-year-old primigravida at 24 weeks gestation is asymptomatic but has bacteriuria detected on routine antenatal screening. Diagnosis: Asymptomatic bacteriuria in pregnancy. Teaching point: Always treat in pregnancy (e.g., with cefalexin) due to risk of pyelonephritis and preterm labour; repeat MSU post-treatment to confirm clearance.
• Case 5 (Recurrent UTI in Postmenopausal Woman): 🌸 A 67-year-old woman presents with her 4th episode of dysuria and frequency in 6 months. Dipsticks and MSU cultures confirm recurrent E. coli UTIs. Diagnosis: Recurrent UTI post-menopause. Teaching point: Consider vaginal oestrogen, lifestyle measures (hydration, timed voiding), and prophylactic antibiotics if persistent.