Fungal Infections
A spectrum from superficial mucocutaneous candidiasis and dermatophyte infections to invasive mould disease in immunocompromised hosts. Management depends on immune status, site, and species identification with susceptibility testing where available.
Key Facts
Key points
- Superficial dermatophytes (tinea): terbinafine 250 mg OD for 1–4 weeks** depending on site; topical terbinafine or clotrimazole for limited disease.
- Oropharyngeal candidiasis: fluconazole 50–100 mg OD for 7 days** or nystatin suspension.
- Invasive candidiasis: echinocandin first line in critically ill (anidulafungin loading 200 mg IV then 100 mg OD** — examples per BNF).
- Invasive aspergillosis: voriconazole first line; liposomal amphotericin B alternatives.
- Pneumocystis jirovecii pneumonia: co-trimoxazole high dose IV/oral — distinct from typical fungi but often grouped clinically.
Overview
Host factors
Neutropenia, transplant, TNF inhibitors, diabetes, ICU stay, broad-spectrum antibiotics predispose to invasive fungal disease.
Diagnostics
Culture, histopathology, (1→3)-β-D-glucan and galactomannan (aspergillosis) — interpret with context.
Clinical Presentation
Superficial
Itchy plaques, oral thrush, vaginal discharge.
Invasive
Persistent fever despite antibiotics, nodular lung infiltrates, skin lesions, fungaemia.
Differential Diagnosis
| Setting | Consider |
|---|---|
| ICU sepsis | Bacterial sepsis, viral infection |
| Lung nodules | TB, malignancy, other moulds |
Diagnosis / Investigation
Microbiology
Blood cultures (Candida), respiratory samples, biopsy when safe.
Imaging
CT thorax for suspected invasive pulmonary mould disease.
Management
Candidaemia (example)
- Anidulafungin IV or caspofungin 70 mg loading then 50 mg OD IV — step-down to fluconazole 400–800 mg OD if susceptible and stable.
Tinea capitis/corporis
- Terbinafine oral or itraconazole — duration varies.
Prognosis
Superficial infections resolve with therapy; invasive disease mortality remains high without immune recovery.
Other Relevant Information
Antifungal stewardship
Therapeutic drug monitoring for voriconazole, posaconazole, itraconazole where indicated.