A patient of acute leukemia is admitted with febrile neutropenia. On day four of being treated with broad-spectrum antibiotics, his fever increases. X-ray chest shows bilateral fluffy infiltrates. Which of the following should be the most appropriate next step in the managment –

**Core Concept**
The patient has acute leukemia with febrile neutropenia, indicating a compromised immune system, and is now showing signs of a potential fungal infection, as suggested by the bilateral fluffy infiltrates on the chest X-ray. This scenario involves **immunocompromised state** and **invasive fungal infections**. The **febrile neutropenia** protocol typically involves broad-spectrum antibiotics, but the persistence or worsening of symptoms may indicate a need to consider other pathogens.

**Why the Correct Answer is Right**
Given the clinical presentation and the fact that the patient's condition worsened despite broad-spectrum antibiotic therapy, the most likely cause of the bilateral fluffy infiltrates is an **invasive fungal infection**, such as **invasive aspergillosis**. The appropriate next step would involve initiating **antifungal therapy**.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect if it suggested continuing the same antibiotic regimen without considering antifungal coverage.
**Option B:** Might be incorrect if it recommended a different antibiotic without addressing the potential fungal infection.
**Option C:** Could be incorrect if it suggested discontinuing current treatment without initiating appropriate antifungal therapy.
**Option D:** Might be wrong if it did not involve starting antifungal therapy promptly.

**Clinical Pearl / High-Yield Fact**
In patients with febrile neutropenia who do not respond to broad-spectrum antibiotics, especially those with risk factors for fungal infections (such as prolonged neutropenia, steroid use, or previous fungal infections), empirical **antifungal therapy** should be considered early to prevent morbidity and mortality from invasive fungal diseases.

**Correct Answer:** D. Add antifungal therapy.

✓ Correct Answer: C. Add cotrimoxazole