Histoplasmosis: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 17: Line 17:


{{CMG}}
{{CMG}}
{{SK}} Ajellomyces capsulatus; Darling disease; Darling's disease


==Overview==
==Overview==
'''Histoplasmosis''', also known as '''Darling's disease''',<ref>{{cite web |url=http://botit.botany.wisc.edu/toms_fungi/jan2000.html |title=Histoplasma capsulatum, cause of histoplasmosis in humans and other animals, Tom Volk's Fungus of the Month for January 2000|format= |work=}}</ref> is a [[disease]] caused by the [[fungus]] ''[[Histoplasma capsulatum]]''. Its symptoms vary greatly, but the disease primarily affects the [[lung]]s. Occasionally, other organs are affected—this form of the disease is called disseminated histoplasmosis, and it can be fatal if untreated.  
'''Histoplasmosis'''<ref>{{cite web |url=http://botit.botany.wisc.edu/toms_fungi/jan2000.html |title=Histoplasma capsulatum, cause of histoplasmosis in humans and other animals, Tom Volk's Fungus of the Month for January 2000|format= |work=}}</ref> is a [[disease]] caused by the [[fungus]] ''[[Histoplasma capsulatum]]''. Its symptoms vary greatly, but the disease primarily affects the [[lung]]s. Occasionally, other organs are affected—this form of the disease is called disseminated histoplasmosis, and it can be fatal if untreated.  


==Pathogen==
==Pathogen==

Revision as of 15:09, 26 September 2012

Histoplasmosis
Histoplasma capsulatum. Methenamine silver stain showing histopathologic changes in histoplasmosis.
ICD-10 B39
ICD-9 115
DiseasesDB 5925
MedlinePlus 001082
MeSH D006660

Histoplasmosis Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Histoplasmosis from other Diseases

Epidemiology and Demographics

Screening

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Chest X Ray

CT

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Case Studies

Case #1

Histoplasmosis On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Histoplasmosis

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Histoplasmosis

CDC on Histoplasmosis

Histoplasmosis in the news

Blogs on Histoplasmosis

Directions to Hospitals Treating Histoplasmosis

Risk calculators and risk factors for Histoplasmosis

For patient information click here

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Synonyms and keywords: Ajellomyces capsulatus; Darling disease; Darling's disease

Overview

Histoplasmosis[1] is a disease caused by the fungus Histoplasma capsulatum. Its symptoms vary greatly, but the disease primarily affects the lungs. Occasionally, other organs are affected—this form of the disease is called disseminated histoplasmosis, and it can be fatal if untreated.

Pathogen

H. capsulatum is found throughout the world and is endemic in certain areas of the United States, particularly in states bordering the Ohio River valley and the lower Mississippi River. (Positive histoplasmin skin tests occur in as many as 80% of the people living in areas where H. capsulatum is common, such as the eastern and central United States.) H. capsulatum grows in soil and material contaminated with bat or bird droppings. The fungus has been found in poultry house litter, caves, areas harboring bats, and in bird roosts (particularly those of starlings). The fungus is thermally dimorphic. In the environment it grows as a brownish mycelium, whereas at body temperature (37°C in humans) it morphs into a yeast. The inoculum is represented principally by microconidia that, once inhaled into the alveolar spaces, germinate and then transform into budding yeast cells.

Skin lesion on the upper lip due to Histoplasma capsulatum infection.

Symptoms

If symptoms of histoplasmosis infection occur, they will start within 3 to 17 days after exposure; the average is 12-14 days. Most affected individuals have clinically-silent manifestations and show no apparent ill effects.[2]The acute phase of histoplasmosis is characterized by non-specific respiratory symptoms, often cough or flu-like. Chest X-ray findings are normal in 40-70% of cases.[2] Chronic histoplasmosis cases can resemble tuberculosis; disseminated histoplasmosis affects multiple organ systems and is fatal unless treated.

While histoplasmosis is the most common cause of fibrosing mediastinitis, this remains a relatively rare disease. Severe infections can cause hepatosplenomegaly, lymphadenopathy, and adrenal enlargement. Lesions have a tendency to calcify as they heal.

Ocular histoplasmosis damages the retina of the eyes. Scar tissue is left on the retina which can experience leakage, resulting in a loss of vision not unlike macular degeneration.

Treatment

Antifungal medications are used to treat severe cases of acute histoplasmosis and all cases of chronic and disseminated disease. Typical treatment of severe disease first involves treatment with amphotericin B, followed by oral itraconazole.[3] In many milder cases, simply itraconazole is sufficient. Asymptomatic disease is typically not treated. Past infection results in partial protection against ill effects if reinfected.

Prevention

It is not practical to test or decontaminate most sites that may be contaminated with H. capsulatum, but the following precautions can be taken to reduce a person's risk of exposure:

  • Avoid areas that may harbor the fungus, e.g., accumulations of bird or bat droppings.
  • Before starting a job or activity having a risk for exposure to H. capsulatum, consult the NIOSH/NCID Document Histoplasmosis: Protecting Workers at Risk. This document contains information on work practices and personal protective equipment that will reduce the risk of infection.

Histoplasmosis in Popular Culture

  • Johnny Cash included a reference to the disease, even correctly noting its source in bird droppings, in the song "Beans for Breakfast".[4]
  • Bob Dylan was hospitalized due to histoplasmosis in 1997, causing the cancellation of concerts in the United Kingdom and Switzerland.[5]
  • In the episode Family, episode 21 of season 3 of the television show 'House, M.D.' a patient was diagnosed with histoplasmosis.[6]

References

  1. "Histoplasma capsulatum, cause of histoplasmosis in humans and other animals, Tom Volk's Fungus of the Month for January 2000".
  2. 2.0 2.1 Silberberg P. "Radiology Teaching Files: Case 224856 (Histoplasmosis)".
  3. "Histoplasmosis: Fungal Infections: Merck Manual Home Edition".
  4. Beans for Breakfast lyrics
  5. CNN - Bob Dylan hospitalized with Histoplasmosis
  6. House episode "Family"

Note: The original version of this article is adapted from the U.S. CDC public domain document at http://www.cdc.gov/ncidod/dbmd/diseaseinfo/histoplasmosis_g.htm

External links

Template:Mycoses

de:Histoplasmose hu:Histoplasmosis nl:Histoplasmose


Template:WikiDoc Sources