Paracoccidioidomycosis
🌎 Anyone living in or visiting endemic areas of Central & South America (esp. Brazil) can get paracoccidioidomycosis.
⚠️ Mortality is <5%, but chronic complications like pulmonary fibrosis and adrenal insufficiency can cause major morbidity.
🦠 About
- Caused by the dimorphic fungus Paracoccidioides.
- Primary route: inhalation of spores.
- Also called Almeida disease, Lutz–Splendore–Almeida disease, Lutz’s mycosis, South American blastomycosis.
📍 Geography & Risk
- Endemic in Mexico, Central & South America (esp. Brazil 🇧🇷).
- Rural outdoor workers (farmers, manual labourers) most affected; men > women (oestrogen protective).
- Thrives in humid, forested areas with rivers and seasonal rains.
- Traditional habit of using twigs to clean teeth → predisposes to oral lesions.
🧬 Pathophysiology
- Inhaled spores trigger a granulomatous reaction, mediated by neutrophils, macrophages, and T-helper lymphocytes.
- Immune response determines whether infection is latent, mild, or disseminated.
🩺 Clinical Features
- Constitutional: fatigue, weight loss, fever.
- Pulmonary: cough, dyspnoea, eventual fibrosis.
- Lymphoreticular: prominent lymphadenopathy, hepatosplenomegaly.
- Bone marrow: anaemia, cytopenias.
- Oral mucosa: painful gingival “mulberry” lesions 🍇 (classic).
- CNS: meningoencephalitis (rare but severe).
🔬 Investigations
- Basic labs: FBC, U&E, Ca, LFTs, CRP.
- CXR: pulmonary infiltrates or fibrosis.
- Biopsy: yeast cells with multipolar budding → “Mickey Mouse head” 🐭 or “pilot’s wheel” 🛞 appearance.
- Culture: Sabouraud agar (slow, 20–30 days).
- Histology: silver or PAS stain highlights fungal elements.
- Immunodiffusion serology: sensitivity ~84%, specificity ~99% in endemic areas.
- Lung biopsy: yeast forms with giant cells & granulomas.
⚠️ Complications
- Pulmonary fibrosis and chronic respiratory failure.
- Adrenal insufficiency (Addison’s disease).
- Secondary infections (bacterial/fungal).
- Severe malnutrition & anaemia.
💊 Management (specialist-led)
- No person-to-person transmission.
- Itraconazole 100–400 mg OD (first line, ~12 months).
- Alternatives:
- Voriconazole (loading 400 mg BD day 1 → 200 mg BD).
- Ketoconazole (200–400 mg/day, but less used).
- Amphotericin B (for severe cases).
- TMP-SMX or Sulfadiazine (longer courses, up to 24 months).
- Treatment typically continued for ~1 year to prevent relapse.
📚 References
