5.3. Fungal Lung Infections

📄 Definition

Fungal lung infections occur when pathogenic fungi infect lung tissue, usually in immunocompromised individuals. Most common types include:

  • Pneumocystis jirovecii pneumonia (PCP) – classically in HIV/AIDS

  • Invasive aspergillosis – transplant, neutropenia

  • Chronic pulmonary aspergillosis (CPA) – post-TB, COPD, sarcoidosis

  • Allergic bronchopulmonary aspergillosis (ABPA) – in asthma/CF patients

🛡️ Causes (at-risk groups)

🧠 Mnemonic: I’VE HAD FUN

  • Immunocompromised (e.g., HIV/AIDS, chemo)

  • Ventilated ICU patients

  • Existing lung disease (e.g., CF, COPD)

  • Haematological malignancy

  • Anti-rejection drugs (transplants)

  • Diabetes mellitus

  • Fungal exposure (compost, soil)

  • Undernutrition

  • Neutropenia

🔬 Pathophysiology

Fungal spores inhaled → evade innate immunity → infect alveoli or bronchi → inflammation ± necrosis ± cavitation.

🔍 Clinical Features

🧠 Mnemonic: FUNGAL

  • Fever

  • Unexplained weight loss

  • Night sweats

  • Gasping for air (progressive SOB)

  • Atypical chest symptoms (dry cough, haemoptysis)

  • Lung infiltrates unresponsive to antibiotics

Investigations

InvestigationRelevance
CXR / HRCT ChestGround-glass opacities (PCP), cavitations (aspergillosis)
Serum β-D-glucanFungal marker (not specific)
Galactomannan (serum/BAL)Specific for aspergillus
Sputum culture / BALDirect microscopy and PCR
HIV testAlways check in PCP
IgE, eosinophils, Aspergillus IgGIf suspecting ABPA/CPA

💊 Management (Trust / BTS guidance based)

Infection TypeFirst-line Management
PCP (Pneumocystis)High-dose co-trimoxazole ± steroids if hypoxic
Invasive aspergillosisIV voriconazole or isavuconazole
ABPAOral steroids + itraconazole
CPALong-term antifungal (e.g., itraconazole) ± resection

🧠 Monitor LFTs + drug levels

🚩Red Flags / Complications

  • Respiratory failure

  • Disseminated fungal sepsis

  • Cavitation + haemoptysis

  • Pneumothorax in PCP

  • Treatment resistance

📅Follow-Up

  • Monitor response with serial imaging (CT)

  • Antifungal duration varies: 3–6 months+

  • ABPA: long-term IgE + eosinophil monitoring

🔎 Last updated in line with BTS Fungal Lung Disease Guidelines & NHS Trust Protocols
Published: June 2021 • Last updated: August 2023
Last reviewed: July 2025
🔒 PASSMAP ensures all content is NICE-aligned and reviewed for Physician Associate Registration Assessment (PARA) success.

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