Chapter 19 Patho Flashcards
- Fungal spores
are inhaled, they reach the lungs and germinate. When this happens, the spores produce a frothy, yeast-like substance that leads to an inflammatory response. Polymorphonuclear leukocytes and macrophages move into the infected area and engulf the fungal spores. The pulmonary capillaries dilate, the interstitium fills with fluid, and the alveolar epithelium swells with edema fluid. Because of the inflammatory reaction, the alveoli in the infected area eventually become consolidated. In severe cases, tissues necrosis, granulomas and cavity formation may be seen. During the healing process, fibrosis and calcification of the lung parenchyma ultimately replace the granulomas. The fibrosis and occasional calcification, the lung tissue retracts and becomes firm. FUNGAL DISEASES ARE SIMILAR TO THOSE SEEN IN TUBERCULOSIS.
- What is the most common fungal infection in the US?
histoplasmosis
- Incidence of histoplasmosis is especially high in what areas?
Mississippi
- The condition called ‘desert bumps’, ‘desert arthritis’, or ‘desert rheumatism’ is associated with which fungal disorder?
coccidioidmycosis
California, Arizona, Nevada, New Mexico, Texas, Utuh.
- What is the other name for Coccidiodmycosis?
California fever, Desert rheumatism, San Joaquin valley disease, Valley fever
- What is used to treat fungal diseases?
Amphotericin B and Itraconazole
- Which form of histoplasmosis is characterized by healed lesions in the hilar lymph nodes as well as a positive histoplasmin skin test response?
Latent asymptomatic disease
- fungal diseases
~ the apical and posterior segments of the upper
lobes are most commonly involved
~ the anatomic changes of the lungs caused by
fungal diseases are similar to those seen in TB
~ cause a chronic restrictive pulmonary disorder
- anatomic alterations of the lungs
~ alveolar consolidation
~ alveolar-capillary destruction
~ caseous tubercles or granulomas
~ cavity formation
- fungal spores
various types are widely distributed throughout the air, soil, fomites, and animals, and even exist in the normal flora of humans
- human fungal disease
(mycotic disease or mycosis)
~ can be caused by primary or ‘true’ fungal
pathogens that exhibit some degree of virulence,
or secondary pathogens that take advantage of
a weakened immune system
- histoplasmosis
~ most common fungal infection in the US
~ caused by the dimorphic fungus Histoplasma
capsulatum
~ especially high along major river valleys of the
Midwest and south
~ 80-90% of the population throughout these areas
show signs of previous infection
~ AKA ‘Ohio Valley Fever’
- H. capsulatum
~ commonly found in soils enriched with bird
excreta, such as soil next to chicken coops, etc
~ may also be carried by bats
- route of acquisition
~ inhalation of the fungal spores that are released
when the soil from an infected area is disturbed
~ when it reaches the alveoli, at body temp, it
converts from its mycelial form (mold) to a
parasitic yeast form
~ clinical manifestations are very similar to those of
TB
- asymptomatic histoplasmosis
is the most common form of histoplasmosis and produces no signs/ symptoms in healthy people
- acute symptomatic pulmonary histoplasmosis
~ tends to occur in otherwise healthy individuals
who have had an intense exposure to H
capsulatum
~ also known as ‘spelunker’s lung’ as it tends to
affect cave explorer’s who come in contact with bat
excrement
- chronic pulmonary histoplasmosis
~ characterized by infiltration and cavity formation
in the upper lobes of one or both lungs
~ this type of histoplasmosis often affects people
with an underlying lung disease such as
emphysema
~ most common in middle-aged white men who
smoke
~ symptoms include- fatigue, fever, night sweats,
weight loss, productive cough, and hemoptysis -
similar to TB
- fungal culture
~ test is considered the gold standard for detecting histoplasmosis ~ 4 weeks or longer for results ~ not the test of choice for dessimated histoplasmosis, due to delayed results
- fungal stain
~ a tissue sample (sputum, bone marrow, lung, or
skin lesion) is stained with dye and examined
under a microscope for histoplasma capsulatum
~ positive result is 100% accurate
~ disadvantage lies with obtaining a sample
- serology
~ blood serology test checks blood serum for
antigens and antibodies
- coccidioidomycosis
~ caused by inhalation of the spores of
coccidiodes immitis
~ spherical fungi carried by wind-born dust particles
- AKA
California fever
Desert rheumatism
San Joaquin Valley disease
Valley fever
~ clinical manifestations are absent in about 60%
of the people who have a positive skin-test result
- chronic progressive pulmonary disease
characterized by nodular growths called fungomas and cavity formation in the lungs
- dessimated coccidioidomycosis
~ the lymph nodes, meninges, spleen, liver, kidney,
skin, and adrenals may be involved
~ skin lesions (bumps on the face and chest) are
commonly accompanied by arthralgia or arthritis
especially in ankles and knees
~ this is commonly called:
- desert bumps
- desert arthritis
- desert rheumatism
- screening & diagnosis
of coccidioidomycosis can be made by direct visualization of distinctive spherules in microscopy of the patient sputum, tissue exudates, biopsies, or spinal fluid
- blastomycosis
AKA -
Chicago disease
Gilchrist’s disease
North American Blastomycosis
~ caused by Blastomyces dermatitidis
~ found in forest soil, decaying wood, animal
manure, abandoned buildings, and chicken poop
~ primary portal is the lungs
~ unlike histoplasmosis, the cough is usually
productive, the sputum purulent
~ extrapulmonary lesions involve skin, bones,
spleen, reproductive tract, liver, kidney, or
prostate gland
~ skin lesions may be 1st sign of disease
often on face, hands, wrists, or legs as nodules
that erode to skin surface
~ diagnosis can be made from visualization of yeast
in sputum smears or fungus can be cultured
- opportunistic pathogens
~ candida albicans
~ Cryptococcus neoformans
~ aspergillus
- thrush
~ candida albicans infection of the mouth
~ characterized by a white, adherent, patchy
infection of the mouth, gums, cheeks, and throat
- aspergillus
~ may be the most pervasive of all fungi
~ found in soil, vegetation, leaf detritus, food and
compost heaps
- allergic bronchopulmonary aspergillosis
~ a form of asthma
~ aspergillus infection
- chest assessment
~ ↑ tactile & vocal fremitus ~ dull percussion note ~ bronchial breath sounds ~ crackles, wheezing ~ pleural friction rub ~ whispered pectoriloquy
- hemodynamic indices
~ CVP ↑ ~ RAP ↑ ~ PA ↑ ~ PCWP normal ~ PVR ↑
- chest xray
~ ↑ opacity ~ cavity formation ~ pleural effusion ~ calcification & fibrosis ~ right ventricular enlargement
- antifungal agents
~ Amphotericin B 1st choice ~ Ketoconazole ~ Itraconazole ~ Fluconazole Diflucan ~ Terbinafine Lamisil
- respiratory care treatment protocols
~ O₂ therapy
~ bronchopulmonary hygiene
~ mechanical ventilation
- Which of the following is or are used to treat fungal diseases?
- Streptomycin
- Amphotericin B
- Penicillin G
- Itraconazole
a. 1 only
b. 2 only
c. 4 only
d. 2 and 4 only
d
- Which of the following forms of histoplasmosis is characterized by healed lesions in the hilar lymph nodes as well as a positive histoplasmin skin test response?
a. Disseminated infection
b. Latent asymptomatic disease
c. Chronic histoplasmosis
d. Self-limiting primary disease
b
- The condition called “desert bumps,” “desert arthritis,” or “desert rheumatism” is associated with which fungal disorder?
a. Histoplasmosis
b. Blastomycosis
c. Coccidioidomycosis
d. Aspergillosis
c
- Incidence of histoplasmosis is especially high in which of the following area(s)?
- Arizona
- Mississippi
- Nevada
- Texas
a. 2 only
b. 4 only
c. 2 and 4 only
d. 2 and 3 only
a. 2 only
- Which of the following is the most common fungal infection infection in the United States?
a. Coccidioidomycosis
b. Histoplasmosis
c. San Joaquin Valley disease
d. Blastomycosis
b
