Mycoses HISTOPLASMOSIS • Inhalation of conidia → Yeast → travel to lymph nodes → spread in body • Bird and bat droppings • Most common presents with acute respiratory symptoms • Fever, cough, chills, headache Disseminated Infections (Immunosuppressed host): • Chronic pulmonary symptoms • Rheumatologic symptoms • Pericarditis • Sclerosing mediastinitis Histoplasmosis Diagnosis: • Histoplasma urinary antigen assay has a sensitivity and specificity of > 85% • < 50% in chronic infection Histoplasmosis Treatment: • Itraconazole is the agent of choice; therapy duration is 6 to 12 weeks for acute infection MUCORMYCOSIS • Risk: Diabetes mellitus, neutropenia, and iron overload states (including deferoxamine administration) • Rhizopus arrhizus, Mucor • Found in the environment on decaying organic debris and soil. • Major blood vessels are invaded, with ensuing ischemia, necrosis, and infarction of adjacent tissues. Mucormycosis has five major clinical forms: 1) Rhinocerebral 2) Pulmonary 3) Abdominal, pelvic, gastric, gastrointestinal 4) Primary cutaneous 5) Disseminated Mucormycosis Diagnosis: • Labs nonspecific • DX relies on a high index of suspicion Mucormycosis Treatment: • Surgical removal of affected tissue • High-dose liposomal amphotericin B, with de-escalation to posaconazole or isavuconazole BLASTOMYCOSIS • Dimorphic, round, budding yeast • Found primarily along the Mississippi and Ohio River valleys • Infection occurs by inhalation of conidia Blastomycosis Symptoms: • Primary pulmonary infection • Cough, fever, chills, muscle aches, joint pain, chest pain • Rarely, dissemination occurs and produces extrapulmonary disease (osteomyelitis or skin infection) • Chronic, subacute to acute pulmonary, systemic or meningitic disease Blastomycosis Diagnosis: • Direct fungal stain of clinical specimens • Confirmed by culture or serology for Blastomyces antibodies • Urinary antigen testing Blastomycosis Treatment: • Fluconazole CRYPTOCOCCUS • Encapsulated yeast • At risk: AIDS, neutropenia, cirrhosis, or organ transplantation • MCC: C. neoformans / C. gattii Pathogenesis: • Inhalation of spores into the respiratory tract, followed by dissemination into susceptible tissues, especially the CNS. MC: CNS CSF: • Increased leukocyte count (mainly lymphocytes) • Increased protein level • A low or normal glucose level, presence of cryptococcal antigen • India ink prep CSF and serum Cryptococcal antigen are highly sensitive Cryptococcosis Treatment: • Amphotericin B plus flucytosine ASPERGILLOSIS • Aspergillus fumigatus, A. flavus, A. niger, A. terreus (Ampho resistant) Invasive aspergillosis • Immunosuppressed patients • Neutropenia • Hematopoietic stem cell transplant recipients Aspergillosis Pathophysiology: • Begins in the respiratory tract and then enters the circulatory system (angioinvasion) Site of infection: • Pulmonary (60%) • Sinusitis • Brain abscess • Disseminated infection SPOROTRICHOSIS Dimorphic fungus found most often in soil, plants, or plant debris Sporotrichosis Symptoms: • Direct inoculation of the organism into the skin or subcutaneous tissue manifests as fixed, “plaque-like” cutaneous sporotrichosis or as lymphocutaneous sporotrichosis • Extracutaneous infection (osteoarticular, pulmonary, ocular, or disseminated) can occur in patients who are immunocompromised Sporotrichosis Diagnosis: • Culture of the organism from affected tissues Sporotrichosis Treatment: • Itraconazole COCCIDIOMYCOSIS • Dimorphic fungus that exists as a mold • Two species: C. immitis refers to isolates from California, and C. posadasii • Inhalation of aerosolized arthroconidia; the fungus then begins its dimorphic change in the lungs and becomes a yeast cell Coccidioidomycosis Symptoms: • Acute or chronic pulmonary infection • Cutaneous infection (~40%) • Meningitis Coccidioidomycosis Diagnosis: • Serology for Coccidioides antibodies Coccidioidomycosis Treatment: • Fluconazole SYSTEMIC CANDIDIASIS Can present: • Isolated fever • Septic shock • Mortality rate of 30% to 40% Invasive Disease: • Meningitis, septic arthritis, and endocarditis Local Disease: • Mouth, throat, skin, scalp, vagina, fingers, nails, bronchi, lungs, or the gastrointestinal tract • 40% to 60% of patients with infection have positive blood cultures Candidiasis Diagnosis: • β-D-glucan assay • Respiratory/urinary tract cultures usually represent colonization Candidiasis Treatment: • Echinocandin (caspofungin, micafungin, or anidulafungin) • Intravascular device removal (if present/possible) #Mycoses #InfectiousDiseases #Fungal #Diagnosis #Management #Infections
