Feverish and unwell for nine days, a 19-year-old hostel student: a case to work up

Why a fever lasting more than a week matters

A fever that has lasted more than a week has outlasted most viral illnesses. In India the common treatable causes include malaria, dengue, typhoid and other bacterial infections, urinary infection and tuberculosis; where he eats and drinks, how the fever has behaved and a few tests narrow them. Tablets from the chemist, often antibiotics, can blunt the fever and make cultures harder to grow.

What to ask in the history

• How the fever started and how it has changed day by day
• Headache, abdominal pain, constipation or diarrhoea, vomiting
• Cough, sore throat, rash, joint pains
• Urinary symptoms; yellow eyes
• Where he eats and drinks: hostel mess, street food, water source; others ill in the hostel
• Travel home or elsewhere, mosquitoes
• Exactly what the chemist gave, and for how long
• Vaccinations; contact with tuberculosis; sexual history

Red flags

• Confusion or drowsiness
• Severe or worsening abdominal pain, a swollen or rigid abdomen
• Blood in the stool or black stools
• Jaundice
• Low blood pressure
• Bleeding or a falling platelet count
• Breathlessness

What to examine

• Temperature with the pulse
• Hydration
• Rash, lymph nodes, throat, tongue
• Abdomen: tenderness, liver, spleen
• Chest
• Neck stiffness, jaundice

First investigations

• Blood cultures, before any further antibiotic
• Full blood count, liver and kidney function, CRP
• Malaria test
• Dengue tests chosen by the day of illness
• Urine routine and culture
• Stool culture
• Chest X-ray
• Further tests, including for tuberculosis, if the fever goes on

Differential diagnosis of a fever lasting more than a week

Grouped, not ranked. Which one fits this patient is for you to work out in the case.

Common mistakes

• Relying on the Widal test.
• Starting another antibiotic before blood cultures are taken.
• Missing a surgical abdomen in a patient who has had a long fever.