Synopsis
Recognise invasive pulmonary fungal disease as a time-critical syndrome, combine host risk, CT, biomarkers and respiratory sampling, and start species-directed antifungal treatment with expert support without waiting for perfect proof. Treatment must be individualised with haematology, transplant, HIV, respiratory, microbiology and pharmacy input.
- Prolonged neutropenia, allogeneic stem-cell transplantation, solid-organ transplantation, high-dose or prolonged corticosteroids and major T-cell suppression create different fungal risks.
- Persistent or recurrent fever despite broad antibacterial therapy may be the only early sign; cough, pleuritic pain or haemoptysis can appear late.
- Urgent thin-section CT is more sensitive than a chest radiograph: nodules, halo sign, wedge-shaped infarcts, cavitation or reversed halo should accelerate specialist review.
- Serum and BAL galactomannan support invasive aspergillosis in the right host; beta-D-glucan is nonspecific and may be negative in mucormycosis.
- Send BAL or tissue for microscopy, fungal culture, molecular testing and biomarkers where safe, but do not delay treatment in a high-risk deteriorating patient.
- Voriconazole is a usual first-line medicine for invasive aspergillosis; suspected Mucorales requires a mould-active alternative such as liposomal amphotericin B and urgent expert input.
- Azoles have major CYP interactions, variable exposure and QT effects; therapeutic drug monitoring and pharmacy reconciliation are core treatment, not optional extras.
- Reverse modifiable immune suppression, recover neutrophils where possible and consider surgical source control for selected localised Mucorales disease or life-threatening haemoptysis.
Key red flags
Persistent or recrudescent fever during prolonged neutropenia, after allogeneic transplantation or under intensive corticosteroid or T-cell suppressive therapy should trigger urgent fungal-risk review even with a normal chest radiograph.
Pleuritic pain, haemoptysis, hypoxaemia and CT nodules with surrounding ground glass or wedge-shaped infarcts suggest vascular invasion. Major bleeding or rapidly rising oxygen need is an emergency.
Investigation priorities
Detect early nodules, halo or reversed-halo patterns, infarcts, cavitation, airway lesions and a target for BAL or biopsy.
Management branches
A high-risk host has persistent fever or respiratory deterioration with compatible CT findings.
- Stabilise oxygenation and sepsis physiology, obtain blood cultures and urgent CT, and involve haematology or transplant, infection or microbiology, respiratory medicine and antifungal pharmacy.
- Send serum biomarkers and pursue BAL or tissue only if the expected diagnostic benefit justifies procedural risk; capture details of prophylaxis and prior antifungal exposure.
- Start prompt mould-active treatment matched to the most likely species and local pathway rather than waiting for culture in an unstable high-probability case.
- Reassess diagnosis, spectrum, drug exposure, interactions and source control within 24 to 72 hours as imaging and mycology evolve.