Pyrexia of Unknown Origion

A middle aged female presented with history of low to moderate severity fever of non-specific character for last 2 months. It is not associated with any sweating, anorexia, weight loss.

There is no systemic complaint.

Physical Examination revealed nothing remarkable except metallic heart sound at mitral area.

Past Medical History:

1. Had Rheumatic fever in late eighties.
2. Developed severe Mitral Valve Disease in early 2000.
3. Had Mitral valve replaced with a prosthetic metallic valve in year 2003.

Current medications:

1.Warfarin, and keeping her INR around 3.0, except that her last reading was around 6 and she had to hold her medicine for a couple of days.

2.Off and on use of digoxin.

3. ACE inhibitor

4. Aspirin

LABs:

1. CBC was normal, with 60% neutrophils

2. ESR came out 60 and it crept up on successive readings.

3. LFTs were normal

4. RFTs deranged, initial creatinine of 3.5 and a GFR of 19ml/min. (her RFTs one month back were absolutely normal), but over the period of one week it improved to 40ml/min.

5. Urine complete showed proteins 2+ and marked hematuria. Spot urinary Na was 35mmole.

6. ECG was normal

7. She was PanCultured and they all came out normal. (she took some quinolone for UTI few days back)

6. Her Serum C3 levels were normal.

9. Her Transthoracic echo revealed mild paravalvular regurge at mitral valve, but TOE confirmed absence of any vegetation.

An ID consultant reviewed her, and it was decided to treat her on the lines of enteric fever. She initially showed some response and was discharged therefore. We also gave her antimalarial cover on discharge. But she developed high grade fever and was readmitted few days later.

Plan: now we have planned to panculture her again, get her CT abdomen and pelvis. Her autoimmune profile is awaited. And we are thinking to get her bone marrow biopsy for Culture and Sensitivity. Any suggestions are welcomed.

WARD ROUND QUESTIONS:

1. What is PUO?
2. What are the common differential diagnosis?
3. How to plan for laboratory investigations?
4. What is empirical therapy, and what to treat in such case?
5. What is the plan of action if initial labs turn out nothing?