Fungal Diseases of the Lung (Des Jardins) Cheat Sheet by Guenevere

When fungal spores are inhaled, they may reach the lungs and germinate.

Polymo­rph­onu­clear leukocytes and macrop­hages move into the infected area and engulf the fungal spores.

Regional lymph node involv­ement commonly occurs during this period.

Airway secretions may also develop at this time.

During the healing process, fibrosis and calcif­ication of the lung parenchyma ultimately replace the granul­omas.

The apical and posterior segments of the upper lobes are most commonly involved.

• Alveol­ar-­cap­illary destru­ction

• Cavity formation

• Bronchial secretions

300 fungal species may be linked to disease in animals

In humans

most exposures to fungal pathogens do not lead to overt infection because humans have a relatively high resistance to them

caused by primary or “true” fungal pathogens that exhibit some degree of virulence or by opport­unistic

• Ohio Valley Fever

• dimorphic fungus Histop­lasma capsulatum

• On the basis of skin test surveys it is estimated that 80% to 90% of the population throughout these areas shows signs of previous infection

• may be carried by bats

• incubation period for the infection is approx­imately 17 days

Only about 40% of those infected demons­trate symptoms, and only about 10% of these patients are ill enough to consult a physician.

• asympt­omatic primary histop­las­mosis

• chronic histop­las­mosis

• Normally it produces no signs or symptoms in otherwise healthy indivi­duals who become infected.

• patient will have a positive histop­lasmin skin test result

• occur in otherwise healthy indivi­duals who have had an intense exposure to H. capsulatum

• Mild signs and symptoms include fever, muscle and joint pain, headache, dry hacking cough, chills, chest pain, weight loss, and sweats.

• This is often referred to as spelun­ker’s lung because it frequently develops after excessive exposure to bat excrement stirred up by indivi­duals exploring caves.

• often affects people with an underlying lung disease such as emphysema

• Signs and symptoms include fatigue, fever, night sweats, weight loss, productive cough, and hemopt­ysi­s—s­imilar to signs and symptoms of tuberc­ulosis.

• In some patients, however, progre­ssive destru­ction of lung tissue and dissem­ination of the infection may occur.

• either self-l­imited histop­las­mosis or chronic histop­las­mosis

• Even though the macrop­hages can remove the fungi from the bloods­tream, they are unable to kill the fungal organisms.

• Depending on which body organs are affected, the patient may develop anemia, pneumonia, perica­rditis, mening­itis, or adrenal insuff­iciency and ulcers of the mouth, tongue, or intestinal tract.

• gold standard for detecting histop­las­mosis

• The disadv­antage of this test is that it takes time for the fungus to grow—4 weeks or longer.

• Treatment delays in patients may prove fatal.

• a tissue sample, which may be obtained from sputum, bone marrow, lungs, or a skin lesion, is stained with dye and examined under a microscope for H. capsulatum

• e. The disadv­antage of this test is that obtaining a sputum sample can be difficult, and obtaining a sample from other sites requires invasive proced­ures.

• checks blood serum for antigens and antibodies

• Tests that check for histop­las­mosis antigen and antibody reactions are relatively fast and fairly accurate.

• caused by inhalation of the spores of Coccid­ioides immitis, which are spherical fungi carried by wind-borne dust particles

• .In the United States, coccid­ioi­dom­ycosis is especially prevalent in Califo­rnia, Arizona, Nevada, New Mexico, Texas, and Utah.

• “California fever,” “Desert rheumatism,” “San Joaquin Valley Disease,” and “Valley Fever.”

• When C. immitis spores are inhaled, they settle in the lungs, begin to germinate, and form round, thin-w­alled cells called spherules.

• The disease usually takes the form of an acute, primary, selfl­imiting pulmonary infection with or without systemic involv­ement.

• absent in about 60% of the people who have a positive skin-test result

• In uncomp­licated cases, patients generally recover completely and enjoy lifelong immunity.

• Chronic progre­ssive pulmonary disease is charac­terized by nodular growths called fungomas and cavity formation in the lungs.

• When this condition exists, the lymph nodes, meninges, spleen, liver, kidney, skin, and adrenals may be involved.

• The diagnosis can be further supported by blood tests that detect antibodies to the fungus or from a culture of the organism from infected fluid or tissue.

• “Chicago disease,” Gilchr­ist’s disease, and North American blasto­mycosis

• occurs in people living in the south-­central and midwestern United States and in Canada

• Cases also have been reported in Central America, South America, Africa, and the Middle East.

• most common among pregnant women and middle­-aged Africa­n-A­merican men

• Primary portal of entry of B. dermat­itidis is the lungs.

• Unlike in histop­las­mosis infection, however, the cough is frequently productive, and the sputum is purulent.

• When the condition is progre­ssive, nodules and abscesses develop in the lungs.

• The skin lesions may, in fact, be the first signs of the disease.

• Yeast dissem­ination also may cause arthritis and osteom­yel­itis, and involv­ement of the central nervous system causes headache, convul­sions, coma, and mental confusion.

• The diagnosis of blasto­mycosis can be made from direct visual­ization of the yeast in sputum smears, or the fungus can be cultured.

• Occurs as normal flora in the oral cavity, genitalia, and large intestine.

• In patients with HIV infection, C. albicans often causes infection of the mouth, pharynx, vagina, skin, and lungs

• Today, Crypto­coccus is most often seen in patients with HIV infection and persons undergoing steroid therapy

• found in soil, vegeta­tion, leaf detritus, food, and compost heaps

• usually occurs in the lungs where it may present in the form of allergic bronch­opu­lmonary asperg­illosis, a form of asthma.

• Stimul­ation of peripheral chemor­ece­ptors

• Pain, anxiety, fever

• Distended neck veins

• Enlarged and tender liver

• Increased tactile and vocal fremitus

• Bronchial breath sounds

• Pleural friction rub (if process extends to pleural surface)

• However, because of the high incidence of nephro­tox­icity associated with amphot­ericin B, the azole antifungal agents now serve as an excellent altern­ative.

In addition, a new class of antifu­ngals known as the echino­candins is now available.

• Because of the hypoxemia associated with the fungal pulmonary condition, supple­mental oxygen may be required.

• Hypoxemia caused by capillary shunting is often refractory to oxygen therapy.

• Because of the excessive production and accumu­lation of mucus sometimes associated with fungal disease, a number of bronchial hygiene treatment modalities may be used to enhance the mobili­zation of bronchial secret­ions.

• may be necessary to provide and support alveolar gas exchange and eventually return the patient to sponta­neous breathing

• Continuous mechanical ventil­ation is justified when the acute ventil­atory failure is thought to be revers­ible.