Post by LymeEnigma on Aug 19, 2008 8:33:14 GMT -8
Physical
Findings on a physical examination are related to the extent and duration of infection.
* Acute pulmonary histoplasmosis
*
o Findings are usually minimal.
o Approximately 5-6% of patients develop rheumatologic manifestations of erythema multiforme, arthritis, and erythema nodosum.
o Auscultation may rarely reveal rales or wheezes. In cases with high inoculum, individuals may develop severe hypoxemia associated with rales that may mimic acute respiratory distress syndrome. Approximately 10% of patients have asymptomatic pleural effusions.
o In 5% of patients, pericarditis may be present and can be associated with rubs.1 Cardiac tamponade is present in 40% of patients presenting with pericarditis.
o Hepatosplenomegaly may occasionally be present.
* Chronic pulmonary histoplasmosis: This form may manifest during pulmonary auscultation as nonspecific rales, wheezes, or findings consistent with the extent of underlying pneumonitis, consolidation, or cavitation.
* Chronic progressive disseminated histoplasmosis: This condition may produce oropharyngeal ulcers involving the buccal mucosa, tongue, gingiva, and larynx. Lesions do not suggest dissemination. Rare cases of isolated lesions have been seen in individuals who are immunocompetent.
* Subacute progressive disseminated histoplasmosis
*
o Gastrointestinal dissemination may result in abdominal mass or intestinal ulcers and lesions. Surgical abdomen may result from intussusception, perforation, or obstruction.
o CNS dissemination may produce findings associated with possible mass lesions or meningismus, including cranial nerve deficits, muscle weakness, ataxia, altered consciousness, or focal deficits.
o Cardiac dissemination may result in signs and complications of endocarditis, including murmurs, peripheral edema, pulmonary rales or wheezes, petechia, or skin lesions.
* Acute progressive disseminated histoplasmosis
*
o CNS manifestations that include a mass lesion, encephalopathy, and meningitis (as observed in the subacute form) occur in 5-20% of patients.
o Hepatosplenomegaly and lymphadenopathy are present in 30% of patients. SVC syndrome may be present with lymphadenopathy severe enough to cause obstruction. The resulting increased venous pressure may manifest as dilatation of collaterals in the neck and thorax; edema of the face, neck, and upper torso; and conjunctiva.
o Cutaneous lesions are present in 10% of patients. Erythematous maculopapular lesions, ulcerations, purpura, and/or manifestations of endocarditis may be present. Oropharyngeal lesions may also be present.
* Presumed ocular histoplasmosis syndrome
*
o Atrophic scars containing foci of lymphocytic cell infiltration termed histo spots may be present and are located posterior to the equator of the eye.
o Approximately 10% of patients have bilateral involvement.
o If the scars are located on the macula, retinal hemorrhage, detachment, or edema may be present.
Causes
The risk of infection is mostly related to environmental exposure and underlying immune status.
* Endemic areas: Living in endemic areas with contaminated soil increases the risk of exposure.
* Inoculum size
*
o Individuals who are immunocompetent and exposed to a low inoculum of histoplasmosis are usually asymptomatic.
o Inhalation of a large inoculum can cause diffuse pulmonary symptoms that may have a protracted course.
* Immune status and comorbid factors
*
o Reactivation, reinfection, or complications of infection usually occur in individuals who are immunocompromised or immunosuppressed.
o Chronic pulmonary histoplasmosis is more prevalent in patients with underlying emphysema.
Full article: www.emedicine.com/med/TOPIC1021.HTM
Histoplasmosis
Article Last Updated: Nov 9, 2007
AUTHOR AND EDITOR INFORMATION
Author: Ryan C Chang, MD, Consulting Staff, Department of Internal Medicine, Divisions of Pulmonary and Critical Care, Kaiser Permanente
Ryan C Chang is a member of the following medical societies: American College of Chest Physicians and American Thoracic Society
Coauthor(s): Irawan Susanto, MD, Director of Pulmonary Consultation and Procedures, Associate Professor, Department of Internal Medicine, Divisions of Pulmonary and Critical Care, University of California at Los Angeles School of Medicine
Findings on a physical examination are related to the extent and duration of infection.
* Acute pulmonary histoplasmosis
*
o Findings are usually minimal.
o Approximately 5-6% of patients develop rheumatologic manifestations of erythema multiforme, arthritis, and erythema nodosum.
o Auscultation may rarely reveal rales or wheezes. In cases with high inoculum, individuals may develop severe hypoxemia associated with rales that may mimic acute respiratory distress syndrome. Approximately 10% of patients have asymptomatic pleural effusions.
o In 5% of patients, pericarditis may be present and can be associated with rubs.1 Cardiac tamponade is present in 40% of patients presenting with pericarditis.
o Hepatosplenomegaly may occasionally be present.
* Chronic pulmonary histoplasmosis: This form may manifest during pulmonary auscultation as nonspecific rales, wheezes, or findings consistent with the extent of underlying pneumonitis, consolidation, or cavitation.
* Chronic progressive disseminated histoplasmosis: This condition may produce oropharyngeal ulcers involving the buccal mucosa, tongue, gingiva, and larynx. Lesions do not suggest dissemination. Rare cases of isolated lesions have been seen in individuals who are immunocompetent.
* Subacute progressive disseminated histoplasmosis
*
o Gastrointestinal dissemination may result in abdominal mass or intestinal ulcers and lesions. Surgical abdomen may result from intussusception, perforation, or obstruction.
o CNS dissemination may produce findings associated with possible mass lesions or meningismus, including cranial nerve deficits, muscle weakness, ataxia, altered consciousness, or focal deficits.
o Cardiac dissemination may result in signs and complications of endocarditis, including murmurs, peripheral edema, pulmonary rales or wheezes, petechia, or skin lesions.
* Acute progressive disseminated histoplasmosis
*
o CNS manifestations that include a mass lesion, encephalopathy, and meningitis (as observed in the subacute form) occur in 5-20% of patients.
o Hepatosplenomegaly and lymphadenopathy are present in 30% of patients. SVC syndrome may be present with lymphadenopathy severe enough to cause obstruction. The resulting increased venous pressure may manifest as dilatation of collaterals in the neck and thorax; edema of the face, neck, and upper torso; and conjunctiva.
o Cutaneous lesions are present in 10% of patients. Erythematous maculopapular lesions, ulcerations, purpura, and/or manifestations of endocarditis may be present. Oropharyngeal lesions may also be present.
* Presumed ocular histoplasmosis syndrome
*
o Atrophic scars containing foci of lymphocytic cell infiltration termed histo spots may be present and are located posterior to the equator of the eye.
o Approximately 10% of patients have bilateral involvement.
o If the scars are located on the macula, retinal hemorrhage, detachment, or edema may be present.
Causes
The risk of infection is mostly related to environmental exposure and underlying immune status.
* Endemic areas: Living in endemic areas with contaminated soil increases the risk of exposure.
* Inoculum size
*
o Individuals who are immunocompetent and exposed to a low inoculum of histoplasmosis are usually asymptomatic.
o Inhalation of a large inoculum can cause diffuse pulmonary symptoms that may have a protracted course.
* Immune status and comorbid factors
*
o Reactivation, reinfection, or complications of infection usually occur in individuals who are immunocompromised or immunosuppressed.
o Chronic pulmonary histoplasmosis is more prevalent in patients with underlying emphysema.
Full article: www.emedicine.com/med/TOPIC1021.HTM
Histoplasmosis
Article Last Updated: Nov 9, 2007
AUTHOR AND EDITOR INFORMATION
Author: Ryan C Chang, MD, Consulting Staff, Department of Internal Medicine, Divisions of Pulmonary and Critical Care, Kaiser Permanente
Ryan C Chang is a member of the following medical societies: American College of Chest Physicians and American Thoracic Society
Coauthor(s): Irawan Susanto, MD, Director of Pulmonary Consultation and Procedures, Associate Professor, Department of Internal Medicine, Divisions of Pulmonary and Critical Care, University of California at Los Angeles School of Medicine