# Fever back after a chest infection in a 48-year-old: a case to work up

> A respiratory case for medical students: a 48-year-old whose fever has returned after he stopped antibiotics early for a chest infection. What to ask, red flags, first tests and the differential.

- Respiratory Medicine · Intermediate · about 20 minutes
- Web page: https://www.medikarya.in/case-studies/48-year-old-man-whose-fever-came-back-after-a-chest-infection
- Work up this patient: https://www.medikarya.in/case-studies/48-year-old-man-whose-fever-came-back-after-a-chest-infection

## How the patient presents

A thin 48-year-old man who stopped his antibiotics early for a chest infection is back with fever, loss of appetite, left-sided chest discomfort and breathlessness on exertion. He smokes and drinks heavily.

## Why a fever that returns after a chest infection matters

When a chest infection seems to settle and then the fever comes back, something has gone wrong: the wrong drug, too short a course, a collection of pus, or a different disease underneath. Each needs a different plan, so find out which.

## What to ask in the history

- The first illness: symptoms, antibiotics, how long he took them and why he stopped
- Fever pattern, sweats, shivering
- Sputum: how much, colour, smell, blood
- Chest pain on breathing, breathlessness
- Weight loss, appetite
- Alcohol and smoking
- Teeth and gums
- Diabetes, HIV, contact with tuberculosis

## Red flags

- Low oxygen saturation or breathless at rest
- Low blood pressure, confusion
- Large amounts of foul sputum
- Coughing up blood
- Signs of fluid in the chest

## What to examine

- Observations
- Nutrition, teeth and gums
- Chest: expansion, dullness, breath sounds, crackles
- Clubbing, lymph nodes

## First investigations

- Chest X-ray
- Full blood count, CRP
- Blood cultures
- Sputum culture and tuberculosis tests
- Ultrasound of the chest, and a sample of any fluid
- CT chest
- HIV test, glucose

## Differential diagnosis of a fever that returns after a chest infection

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

### A different organism

- Tuberculosis
- Resistant bacteria
- Fungal infection

### Complications

- Parapneumonic effusion or empyema
- Lung abscess

### Something underneath

- Lung cancer blocking an airway
- Aspiration
- Bronchiectasis

### Elsewhere

- Drug fever
- Another infection
- Pulmonary embolism

## Common mistakes

- Simply restarting the same antibiotic.
- Missing fluid in the chest that needs draining.
- Forgetting tuberculosis.

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A study guide for medical students, not medical advice. Follow your institution's protocols in practice.