[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Dimorphic fungi](https://durgical.com/en/microbiology/groups/dimorphic-fungi/) › Paracoccidioides brasiliensis [Microbiology](https://durgical.com/en/microbiology/) · [Dimorphic fungi](https://durgical.com/en/microbiology/groups/dimorphic-fungi/) # Paracoccidioides brasiliensis - Fungus - Exam priority: medium A dimorphic soil fungus of rural and coffee-growing areas; it causes mouth ulcers, chronic lung damage and sometimes adrenal insufficiency. Updated 2026-11-01 Also called: Paracoccidioides lutzii, South American blastomycosis ## Key points - Large yeast with many buds around it (helm look) - Adult male farmer who smokes, with mouth ulcers and lung damage - Far more common in men: estrogens block conversion to yeast - Look for adrenal insufficiency - Itraconazole; trimethoprim-sulfamethoxazole as an alternative ## At a glance **Shape** Large yeast with many small buds spread around the whole cell **Family** Ajellomycetaceae (Onygenales) **Type** Thermally dimorphic fungus: mold in soil, yeast in tissue **Stain** KOH on sputum or scrapings; silver (GMS) and PAS on biopsy **Size** Large yeasts, up to about 30 µm ## Morphology - In the environment and at room temperature: mold with conidia - In tissue: a large thick-walled mother cell - Several small buds sprout at once all around its edge, so the cell looks like a spoked wheel or a ship's helm seen face on ## Transmission - Inhaling conidia from soil during farm work - Rarely by direct inoculation of skin or oral mucosa - Not spread from person to person **Reservoir:** Soil of humid tropical and subtropical farmland; Armadillos (possible reservoir) ### Isolation precautions What the care team adds to standard precautions. - Standard ## Virulence factors - Conversion to yeast at body temperature; estrogens block this step, which helps explain why the adult form is far more common in men - Survival inside macrophages and a granulomatous response with fibrosis - Wall antigens (glycoprotein gp43) that modulate the immune response ## Diseases it causes - Paracoccidioidomycosis: chronic adult form (lungs and mucosa) and acute or juvenile form (lymph nodes, liver, spleen and marrow) [Paracoccidioidomycosis →](https://durgical.com/en/conditions/paracoccidioidomycosis/) ## Clinical picture - Mouth and lip ulcers with a granular base and pinpoint bleeding, which can mimic cancer - Lung infiltrates and fibrosis, worse with smoking - Large neck lymph nodes that may drain - Adrenal insufficiency in disseminated disease ## Diagnosis - KOH on sputum, ulcer scrapings or pus: the multiple-budding yeast is diagnostic - Biopsy with silver (GMS) or PAS - Culture, slow - Serology (immunodiffusion) for support and follow-up; P. lutzii can give false negatives with P. brasiliensis antigens ## Treatment Azoles (itraconazole) for mild and moderate disease; trimethoprim-sulfamethoxazole as an alternative; amphotericin B for severe disease, followed by an azole. Treatment is long. Drug class only; doses and regimens are set by the clinician from the current guideline. In Pharmacology: - [Itraconazole](https://durgical.com/en/pharmacology/itraconazole/) - [Amphotericin B](https://durgical.com/en/pharmacology/amphotericin-b/) ## Prevention - No vaccine - Stopping smoking reduces lung damage - Early diagnosis in rural workers with chronic mouth ulcers ## In Colombia Colombia is endemic, above all in rural and coffee-growing areas of Antioquia, Santander, Valle del Cauca, Huila, Nariño and the Coffee Axis. The species P. restrepiensis has been isolated mostly from Colombian patients. It is not a notifiable disease, so its true frequency is unknown. ## Memory aid Picture a pin cushion: one big yeast stuck all round with little bud-pins; then picture the coffee farmer with mouth sores. ## Test yourself Think of the answer, then tap the question to see it. ## What does Paracoccidioides look like in tissue or on KOH? A large thick-walled yeast with many small buds sprouting all around its edge, like a ship's helm. ## Why is adult paracoccidioidomycosis far more common in men? Estrogens inhibit the mold-to-yeast conversion; farm-work exposure also plays a part. ## Which endocrine complication is sought in disseminated paracoccidioidomycosis? Adrenal insufficiency. ## In what kind of Colombian areas is paracoccidioidomycosis concentrated? In humid rural areas, mainly coffee-growing ones, in Antioquia, Santander, Valle, Huila, Nariño and the Coffee Axis. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/microbiology/paracoccidioides-brasiliensis/) ## Related - [Blastomyces dermatitidis](https://durgical.com/en/microbiology/blastomyces-dermatitidis/) - [Histoplasma capsulatum](https://durgical.com/en/microbiology/histoplasma-capsulatum/) ## Related conditions - [Paracoccidioidomycosis](https://durgical.com/en/conditions/paracoccidioidomycosis/) ## What the colours mean **Gram-positive** Thick peptidoglycan wall: stains purple. **Gram-negative** Thin wall with an outer membrane: stains pink. **Acid-fast** Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain. [← Back to the group: Dimorphic fungi](https://durgical.com/en/microbiology/groups/dimorphic-fungi/) Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Thinking in paracoccidioidomycosis: a delayed diagnosis of a neglected tropical disease, case report and review of clinical reports and eco-epidemiologic data from Colombia since the 2000](https://pmc.ncbi.nlm.nih.gov/articles/PMC7011283/) (BMC Infectious Diseases (PMC, NLM), 2020); [Paracoccidioidomycosis: Current Status and Future Trends](https://pmc.ncbi.nlm.nih.gov/articles/PMC9769695/) (Clinical Microbiology Reviews (PMC, NLM), 2022). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/microbiology/paracoccidioides-brasiliensis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/paracoccidioides-brasiliensis/