Tropical lung

Tropical lung

1. Histoplasmosis

   • Clinical manifestations
     • Pneumonia with mediastinal or hilar lymphadenopathy
     • Mediastinal or hilar masses
     • Pulmonary nodule
     • Cavitary lung disease
     • Pericarditis with mediastinal lymphadenopathy
     • Pulmonary manifestations with arthritis or arthralgia plus erythema nodosum
     • Dysphagia caused by esophageal narrowing
     • Superior vena cava syndrome or obstruction of other mediastinal structures
   • Microbiology
     • Systemic and endemic mycosis in a wide area of ​​the Americas
     • Caused by the inhalation of infective particles of the thermal dimorphic fungus Histoplasma capsula-tum.
     • This fungus grows in a filamentous form, but once it enters the host's tissues, it becomes yeast
   • Diagnosis
     • Histopathology using stains for fungi, cultures, antigen detection, and serologic tests for Histoplasma-specific antibodies can all help make the diagnosis of pulmonary histoplasmosis
     • Histopathology and cytology
     • Fungal cultures
     • Antigen detection
     • Serology
       • complement fixation, immunodiffusion, and enzyme immunoassay.

2. Paracoccidioidomycosis

   • Diagnosis
     • Is based upon the microscopic visualization of fungal elements suggestive of Paracoccidioides spp and/or by culturing this fungus from clinical specimens
     • Serologic testing can be useful both for diagnosis and for monitoring the response to therapy
     • The tests used to diagnose acute/subacute paracoccidioidomycosis are identical to those used for chronic paracoccidioidomycosis, and are discussed in detail separately.
   • Microbiology
     • Systemic mycosis caused by Paracoccidioides brasiliensis
     • Dimorphic fungus endemic in Central and South America
     • The route of transmission is the inhalation of conidia 4, which transform into yeast in the tissues
   • Clinical manifestations
     • Only a minority of patients (<5 percent) eventually develop clinically manifested disease.
     • lymphadenopathy, hepatosplenomegaly, and/or bone marrow dysfunction (eg, aplastic anemia)
     • Anemia
     • Hypergammaglobulinemia
     • Eosinophilia
     • Hypoalbuminemia
     • Hyperbilirubinemia
     • Mildly elevated transaminases

3. Coccidioidal infection

   • Diagnosis
     • The diagnosis of primary pulmonary coccidioidomycosis in patients who have had a known or suspected exposure in an endemic area and present with any of the following:
     • A respiratory illness of one week or more with an infiltrate on chest radiograph, especially if there is upper lobe involvement or hilar or mediastinal adenopathy.
     • Presumed community-acquired pneumonia (CAP) with continued pulmonary symptoms despite appropriate empiric antibacterial therapy.
     • New onset of diffuse, symmetrical arthralgias or rash, particularly if the findings are consistent with erythema nodosum or erythema multiforme.
     • Other findings suggestive of coccidioidomycosis, including night sweats, marked fatigue, or unexplained peripheral blood eosinophilia.
   • Microbiology
     • Is caused by the dimorphic fungi of the genus Coccidioides
     • It is now recognized as consisting of two species, Coccidioides immitis and Coccidioides posadasii
     • There is no clinical or microbiologic distinction between these two species, and henceforth the organism will be referred to as Coccidioides.
   • Clinical Manifestations
     • Pulmonary manifestations
       • Chest pain, cough, and fever
     • Extrapulmonary manifestations
       • Rheumatologic symptoms
         • symmetric arthralgias, particularly of the ankles, knees, and wrists, has been called "desert rheumatism."
       • Cutaneous manifestations
         • erythema nodosum (usually manifesting as painful, erythematous nodules on the lower extremities), as well as erythema multiforme, which is often seen in a necklace distribution.