[
Recent Advances in Chest Medicine
]
Clinical Approach and Management for Selected
Fungal Infections in Pulmonary and Critical
Care Patients
Andrew H. Limper, MD, FCCP
Fungal lung infections are widely encountered and present both diagnostic and therapeutic
challenges. The increasing prevalence of fungal infections is correlated with increasing
numbers of immunocompromised patients, enhanced awareness of these infections, and
improved methodologies for diagnosis. Fortunately, additional antifungal agents are available
to combat these important infections. This review covers the clinical approach to fungal lung
infections encountered in pulmonary and critical care practice.
CHEST 2014; 146(6):1658-1666
Fungal lung infections are widely diagnosed
and managed by pulmonary and critical
care physicians.1 The increasing prevalence
of fungal infections is associated with
growing numbers of immunocompromised
patients, clinical awareness of these infections, and improved approaches for diagnosis.2 Fortunately, newer antifungal agents
have been developed to combat these
important infections. This review will discuss the clinical approach to fungal lung
infections.
Traditional and Newer Classes
of Antifungal Agents
While the past decade has seen an increase
in the number of antifungal agents (Table 1),
these agents must be considered in balance
with traditional agents and the appropriate agent selected depending on the
clinical scenario. In general, individualized
Manuscript received February 6, 2014; revision accepted July 28, 2014.
AFFILIATIONS: From the Thoracic Diseases Research Unit and the Division of Pulmonary and Critical Medicine, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN.
CORRESPONDENCE TO: Andrew H. Limper, MD, FCCP, Mayo Clinic
College of Medicine, Gonda Bldg 18-S, Rochester, MN 55905; e-mail:
limper.andrew@mayo.edu
1658 Recent Advances in Chest Medicine
therapies for fungal infections must be
based upon defining the causative fungus,
considering the severity of infection, and
placing treatment options in perspective
with selected features of individual patients.
Polyenes
Amphotericin B: The archetypal polyene
antifungal is amphotericin B deoxycholate.
Despite concerns about host toxicities, this
agent continues to be used as a therapeutic
option for severe fungal infections. This is
particularly true for life-threatening infection,
including invasive aspergillosis, in some
cases of systemic candidiasis and cryptococcosis, and for severe histoplasmosis,
blastomycosis, coccidioidomycosis, and
mucormycosis. Polyene antifungals bind
to sterols present in the fungal membrane,
inducing a defect in the membrane that leads
to cell leakage and death.3
© 2014 AMERICAN COLLEGE OF CHEST PHYSICIANS. Reproduction of
this article is prohibited without written permission from the American
College of Chest Physicians. See online for more details.
DOI: 10.1378/chest.14-0305
[
146#6 CHEST DECEMBER 2014
]
TABLE 1
] Current Antifungal Agents and Mechanisms of Action
Class
Relevant Medications
Mechanisms of Action
Polyenes
Amphotericin B deoxycholate,
lipid formulations of amphotericin B
Binds to ergosterol, leading to pore formation in
the fungal cell membrane
Triazoles
Fluconazole
Inhibits fungal membrane ergosterol synthesis
by inhibiting C-14-a-demethylase
Itraconazole
Voriconazole
Posaconazole
Echinocandins
Caspofungin
Inhibits fungal cell wall b-1,3-D-glucan synthesis
Anidulafungin
Micafungin
Amphotericin B deoxycholate must be administered
intravenously. Careful monitoring during therapy is
essential and includes measuring creatinine, BUN, potassium, and magnesium levels; monitoring CBC counts;
and assessing liver function. In general, monitoring
should be performed frequently (every day or two)
during the administration of amphotericin. Renal toxicity
can develop precipitously. Many practitioners premedicate patients with antipyretics, antihistamines, antiemetics,
or meperidine to decrease febrile reaction and chills.
IV infusion should be over 2 to 6 h, since rapid administration may precipitate life-threatening hyperkalemia
and arrhythmias.4 There is additive renal toxicity with
other nephrotoxic agents, such as aminoglycosides.
Adequate hydration reduces the risk of nephrotoxicity.
Nephrotoxicity of amphotericin B is predominantly dose
dependent. In severely immunocompromised patients,
in patients with renal impairment, in patients receiving
other nephrotoxic drugs, or in situations requiring doses
of amphotericin B ⱖ 1.0 mg/kg/d, strong consideration
should be given for lipid preparations of amphotericin
to avoid the high incidence of renal toxicity. Liver toxicity
can occur, but it is rare.
Lipid Formulations of Amphotericin: Several lipidassociated formulations have been developed, including
liposomal amphotericin B, amphotericin B lipid complex,
and amphotericin B-cholesterol sulfate complex. These
agents are significantly less nephrotoxic than amphotericin B deoxycholate.5 Lipid formulations have largely
supplanted the use of amphotericin B deoxycholate in
the United States and most of Europe and Canada, particularly in immunocompromised patients. However,
in developing portions of the world, amphotericin B deoxycholate continues to be used more frequently. Information supporting improved efficacy of lipid formulations
over amphotericin B deoxycholate is limited. Monitoring
journal.publications.chestnet.org
for side effects should be performed in a fashion parallel
to that described for amphotericin B deoxycholate.
Studies in animal models indicate that liposomal formulations of amphotericin exhibit higher effective CNS
concentrations than either amphotericin B deoxycholate or amphotericin B lipid complex.6 Conclusive data
in humans to further support this finding are not yet
available.7
Triazole Antifungals
The azole antifungals are orally active and include itraconazole, fluconazole, voriconazole, and posaconazole.
Triazoles inhibit fungal C-14-a-demethylase mediating
conversion of lanosterol to ergosterol. Interactions of
azole drugs with human P450 cytochromes are well
described.8 Hence, azole-related drug interactions can
be challenging in immunocompromised hosts, particularly patients receiving multiple other agents, such as
those who have undergone transplant and those with
HIV. Interactions occur with cyclosporine, benzodiazepines, statins, and certain anti-HIV drugs as a result of
altered rates of metabolism and induction of the relative
cytochrome P450 activity. In addition, all of the azole
agents have the ability to prolong QTc and should be
used with caution, particularly in the presence of other
agents that may also exert this effect. Earlier agents such
as ketoconazole, which is an imidazole, have significant
adverse effects on steroid hormone levels and adrenal
function and have been supplanted by the newer triazole agents. In view of adrenal and potentially severe
liver toxicity of oral ketoconazole, and with available
less toxic and more effective triazoles, ketoconazole
should no longer be used as frontline therapy.9,10 In
addition, azoles are class C drugs and contraindicated
during pregnancy. In contrast, amphotericin is rated
class B for pregnancy and is preferred during severe
infection.
1659
Itraconazole: Itraconazole contains a lipophilic tail
enhancing activity against molds such as Aspergillus
species.11 Itraconazole is effective for some Aspergillus
species infections, mucosal candidal infections, histoplasmosis, blastomycosis, and coccidioidomycosis.
Unfortunately, due to high protein binding and poor
penetration, it is not effective for CNS infections. Itraconazole is manufactured as either oral capsules or oral
solution. The oral form requires gastric acid for absorption, and should be administered with food or acidic
beverages. Concurrent use of antacids and proton-pump
inhibitors should be avoided. To overcome problems
with variable absorption, itraconazole is also available in
a cyclodextrin solution. The oral solution should be provided on an empty stomach. When using itraconazole, it
is important to routinely assure that adequate levels of
itraconazole are present in serum. Dose adjustments of
orally administered itraconazole are not required in
patients with renal impairment. Itraconazole is metabolized in the liver and caution should be used in patients
with significant hepatic impairment. Side effects of itraconazole are uncommon, but may include peripheral
edema, rash, diarrhea, and nausea. Serious, though
uncommon, side effects include worsening of congestive
heart failure, Stevens-Johnson syndrome, and hepatotoxicity. As with other azole compounds, interactions
occur with many such drugs related to its metabolism
by the cytochrome P450 and related systems.
Voriconazole: Voriconazole is an additional extendedspectrum azole available in both IV and oral forms.
Voriconazole is widely used for invasive aspergillosis
and other fungal infections.12 As with most azoles, the
drug should be used cautiously in patients receiving
other drugs that are metabolized via the cytochrome P450
pathways and related pathways, including CYP34A,
CYP2C9, CYP2C19, and CYP3A4. Voriconazole should
also be used with caution in patients with hepatic cirrhosis.
Due to the cyclodextrin component, IV voriconazole
should also be used with restraint in patients with renal
insufficiency, as the cyclodextrin component may accumulate. In such instances, the oral form, which lacks
cyclodextrin, may be used instead. Dose modifications
are not required for voriconazole in patients with mild
to moderate renal impairment. If IV voriconazole is
absolutely necessary in patients with moderate to severe
renal insufficiency, serum creatinine levels should be
monitored. Voriconazole should generally not be used
in patients with severe hepatic insufficiency unless other
options are limited and potential benefits outweigh the
risks. Patients should avoid direct sunlight, since photo-
1660 Recent Advances in Chest Medicine
sensitivity occurs.13 With widening use of voriconazole
in prophylaxis of severely immunosuppressed patients,
chronic dermatologic photosensitivity reactions have
been reported. Furthermore, there appear to be increased
reports of nonmelanomatous skin cancer in such
patients.13 However, such immunosuppressed individuals have multiple risk factors for skin cancer, and
recent studies suggest that the risk of malignancies
directly attributable to voriconazole alone may not be
significant.14 Nonetheless, clinicians caring for such
patients need to be vigilant of skin toxicity and malignancies (including melanoma).15 Side effects also
include nausea, vomiting, rash, and liver abnormalities.
Severe liver dysfunction has rarely been reported. Peripheral edema does occur with voriconazole, though much
less frequently than observed with itraconazole. Approximately one-third of patients experience visual disturbances,
including photopsia, while receiving voriconazole. This
complication generally lasts only for several hours and
then dissipates. Over days to weeks, the visual disturbance
becomes less obvious to the patient.1 Metabolism of the
drug can be variable and monitoring of serum levels can
be helpful.
Posaconazole: Posaconazole is useful for use as prophylaxis against invasive fungal infections including
aspergillosis and disseminated candidiasis in immunocompromised patients and for the treatment of oropharyngeal candidiasis in patients with HIV or severe
oropharyngeal candidiasis refractory to fluconazole and
itraconazole.16 This agent has proven effective when
used as second-line therapy in severely immunocompromised patients with refractory Aspergillus species
infection, and also has been used to treat coccidioidomycosis.17 The agent also has activity against Mucorales
fungi. Typical adverse effects of posaconazole include
abdominal discomfort and diarrhea. Serious toxicities
also include occasional hepatic dysfunction. Posaconazole has saturable absorption and requires adequate
dietary fat for optimal uptake. Dose adjustments for
posaconazole are not necessary in patients with mild to
severe hepatic impairment or renal insufficiency. Clinical
monitoring for potential drug toxicity should include
evaluating liver function tests. There are now oral extendedrelease tablets of posaconazole available that are replacing
the older oral suspensions, which were more poorly
absorbed. In addition, an IV formulation of posaconazole has been released, which will expand its use in
serious fungal infections.
Fluconazole: Fluconazole exhibits reduced lipophilicity,
allowing for easier administration, and has good activity
[
146#6 CHEST DECEMBER 2014
]
against Candida albicans.1 It is used for prevention and
treatment of both mucosal and invasive candidal diseases, but also exhibits significant activity against
coccidioidomycosis and cryptococcosis. Modifications of
fluconazole dosing are necessary in renal insufficiency.
Doses are reduced by 50% when the creatinine clearance
is , 50 mL/min. Patients on hemodialysis require replacement of the entire dosage following dialysis. Compared
with other azole antifungal agents, such as itraconazole,
voriconazole, and posaconazole, drug-drug interactions
are relatively less frequent with fluconazole, as fluconazole
is a less active inhibitor of P450 and related pathways.
Side effects are relatively uncommon, but can include
rash, pruritus, headache, nausea and vomiting, and
increased transaminase levels.
Other Emerging Azoles: Additional studies are underway with ravuconazole, isavuconazole, and albaconazole
in a variety of fungal infections.18 The relative efficacies
and indications of these agents have not yet been well
defined.
Echinocandins
This class of agents acts to disrupt fungal cell walls by
inhibiting of b-1,3-d-glucan synthase enzymes located
in the plasma membrane.
Caspofungin: Caspofungin exerts fungicidal activity
against candida organisms and fungistatic activity
against Aspergillus species. The principal initial usage
for caspofungin was chiefly for candidiasis. However,
this agent has also been used in the treatment of febrile
neutropenia and as a component of salvage therapy for
invasive Aspergillus pneumonia. Indications for use not
approved by the US Food and Drug Administration also
include empirical use in patients with suspected invasive
fungal infection and as prophylaxis in severely immunocompromised patients. Basic investigations indicate
potential activity against Pneumocystis species. However,
definitive clinical data to support use of echinocandins
in patients with Pneumocystis jirovecii pneumonia are
lacking, and echinocandins should not be used as firstline or stand-alone therapies.19,20 Cryptococcosis is resistant to caspofungin, in part due to melanization of the
cell wall.21 Caspofungin is available as an IV infusion.
Since it is metabolized in the liver, dosage adjustment is
required during hepatic impairment. Caution should be
used in patients with impaired liver function, during
pregnancy, or in patients receiving cyclosporine. Of
interest, caspofungin and the other echinocandins do
not interfere with the cytochrome enzymes. However,
drug-drug interactions may still occur with cyclosporine
journal.publications.chestnet.org
and tacrolimus, rifampin, and certain anti-HIV drugs.
Other side effects include elevations of liver enzymes,
facial swelling, headache, pruritus, and nausea. Rarely,
hypersensitivity reactions and, very rarely, anaphylaxis
has occurred with all of the echinocandin agents.
Anidulafungin: Anidulafungin is used in candidemia,
invasive candidiasis, and candidal esophagitis.22
Anidulofungin also has activity against Aspergillus
species. It is used off label as empirical therapy for
suspected candidemia in non-neutropenic patients.
Anidulofungin is well tolerated. Common side effects
include hypokalemia and diarrhea. More clinically significant side effects include DVT and, on rare occasions,
liver toxicity.
Micafungin: Micafungin has activity against Candida
species and Aspergillus species, and has been approved
for treatment of invasive candidiasis and for prophylaxis against invasive candidal infection in patients
who have received hematopoietic cell transplant and
against candidal esophagitis.23 Adverse events include
rash; abdominal discomfort with nausea, vomiting, or
diarrhea; and hyperbilirubinemia. Phlebitis may occur
in the injection site. All three of the currently licensed
echinocandins should be regarded as equally effective
for candidemia.
Clinical Features of Fungal Lung Infections
Fungal infections can occur in either immunocompetent or immunosuppressed individuals. The clinician
should be aware of clinical signs that may suggest the
presence of fungal infections, such as persistent lung
infiltrates, with or without mediastinal lymphadenopathy (Table 224). Disseminated calcified granulomas in
lung and spleen may also be observed and are typical of
endemic fungal infections, particularly infection with
histoplasmosis. Such infiltrates do not respond to usual
antibacterial antibiotics. Most fungal infections in
immunocompromised hosts are due to either candidal bloodstream infections or to invasive Aspergillus
species tissue infections, including invasive Aspergillus
pneumonia. However, other infections, including the
endemic mycoses (coccidioidomycosis, histoplasmosis,
and blastomycosis, depending on regional geography)
and P jirovecii pneumonia remain a threat to immunocompromised patients, as well. It is also important to be
aware that the incidence of candidal infections by species
other than C albicans, as well as the incidence of more
resistant mycelial mold infections, including mucormycosis and Scedosporium species infections, are also
increasing.
1661
TABLE 2
] Factors Suggesting Possible Fungal Lung
Infections
Factors
Nonresolving pulmonary infiltration with fever that fails
to resolve with standard antibiotic therapies directed
at bacteria
Patients with significant neutropenia (absolute neutrophil
counts , 500/mL for . 21 d), hematologic malignancy
or hematopoietic cell transplant or solid organ
transplantation, patients with malignancies receiving
chemotherapy
Patient with emerging immunocompromising conditions
(chronic corticosteroid use, novel immune suppression,
renal insufficiency, COPD, diabetes mellitus, cirrhosis)
Exposure or recent travel to endemic geographic
regions
Hilar and/or mediastinal adenopathy (may or may not
be present)
Associated skin lesions (erythema nodosum,
morbilliform or toxic rash), arthritis, bone lesions,
CNS dissemination
Adapted from Limper.24
Therapeutic Approaches to the
Endemic Mycoses
The endemic mycoses include histoplasmosis, blastomycosis, and coccidioidomycosis. These fungi can infect
both immunocompetent and immunocompromised
individuals. Cryptococcal pneumonia and meningitis
are also considerations in such patients. Effective diagnosis of the endemic mycoses relies on accurate recognition of geographic predilections, clinical features, and
effective use of relevant serologic and polymerase chain
reaction assays, bronchoscopy, and lumbar puncture,
when indicated. The clinical diagnoses of these infections
are reviewed in detail elsewhere.25-27 Therapeutic decisions
for the endemic mycoses are based on whether the host
exhibits immunocompetence. In general, infections of
lesser severity are managed with extended-spectrum
azoles, while more severe infections may require initial
therapy with liposomal amphotericin to induce remission
prior to longer-term therapy with extended-spectrum
azoles. Detailed guidelines outlining therapies for each
of the endemic mycoses and cryptococcosis should be
consulted to guide individual clinical decisions.1
Histoplasmosis and Related Sequelae
Histoplasma capsulatum can cause infections including
solitary pulmonary nodules with or without adenopathy, broncholithiasis, and mediastinal granuloma and
fibrosis; symptomatic or progressive disseminated
pulmonary histoplasmosis, including histoplasmosis-
1662 Recent Advances in Chest Medicine
associated ARDS; and chronic pulmonary histoplasmosis.
In immunocompetent patients with pulmonary nodules
or isolated broncholithiasis and minimal symptoms,
azole therapy is usually not required.
In patients with symptomatic or active histoplasmosis
nodular infiltration with or without significant adenopathy, therapy with itraconazole at a dosage of 200 mg bid
for 3 months is often prescribed to resolve the infection
and to possibly reduce sequelae such as fibrosing mediastinitis. However, there are no data available that definitely demonstrate that antifungal therapy reduces the
incidence of fibrosing mediastinitis. In the setting of
mediastinal granuloma with associated bulky adenopathy,
with positive serologies or urine antigen testing documenting recent or active infection, a trial of itraconazole,
200 mg bid, may also be instituted for 12 weeks.25 In
patients with clinical improvement, treatment up to
12 months may be then prescribed.
Unfortunately, in most cases of well-established fibrosing mediastinitis, azole therapy has not proven effective.
Antifibrotic agents and systemic corticosteroids are also
generally not useful in fibrosing mediastinitis. Fibrosing
mediastinitis may also result in severe vascular or airway compromise requiring intravascular stents, placement of ronchial stents, or both and potentially
bronchoplasty or other surgical interventions.
Broncholithiasis can result from calcification of a lymph
node previously infected with histoplasmosis that may
erode into an airway. When broncholithiasis is complicated by hemoptysis or atelectasis, bronchoscopic evaluation and either bronchoscopic or surgical removal is
indicated, with the caution that broncholiths may cause
significant bleeding when removed endoscopically.
In symptomatic patients with mild or moderate symptomatic pulmonary histoplasmosis-related pneumonia,
therapy is usually initiated with itraconazole for 12 weeks.
However, in patients with severe pulmonary histoplasmosis, such as those with life-threatening disseminated
pulmonary infections with severe gas-exchange abnormality (Fig 1), therapy should be initiated with liposomal
amphotericin B until clinical improvement is established.
This is followed by maintenance therapy with itraconazole, 200 mg bid, for at least 3 months. In patients with
chronic pulmonary histoplasmosis, often with cavitary
disease, itraconazole, 200 mg bid, for 12 to 24 months
may be used.28
Immunocompromised patients with histoplasmosis are
usually managed in a parallel fashion with modifications.
[
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]
nodules, and chronic fibrocavitary disease. Dissemination
does occur with spread to the skin being most common.
Dissemination to bone, and rarely to the CNS, can also
occur. For mild to moderately ill immunocompetent
patients, oral itraconazole, 200 bid for 6 months, will
generally suffice.26 However, in patients with bone involvement, prolonging the treatment course with itraconazole
to a total of 12 months is needed. In severe pulmonary
blastomycosis, such as with diffuse lung injury or severe
systemic disease, initial therapy should be based on daily
IV liposomal amphotericin B until clinical improvement
is established.1 Subsequently, oral itraconazole, 200 mg
bid for an additional 6 months, should be administered.
Voriconazole, 200 mg bid, may be used as an alternative, based on in vitro and limited clinical data.31 Adjunctive corticosteroids, such as for histoplasmosis, can be
beneficial in selected cases of severe blastomycosisrelated ARDS.
Figure 1 – CT image of progressive disseminated histoplasmosis. This
image was obtained from a 72-y-old woman with rheumatoid arthritis
who was undergoing immunosuppression treatment with adalimumab
and methotrexate. She developed progressive gas-exchange abnormalities.
CT scanning documented widely disseminated miliary micronodular
infiltrates. Histoplasmosis was confirmed by bronchoscopy with BAL and
with Histoplasma species urinary antigen.
For instance, immunocompromised patients with mild
to moderate symptomatic histoplasmosis are often
treated with itraconazole, 200 mg tid, for the first 3 days
followed by 200 mg bid for 12 months.1 Severely immunocompromised patients, such as patients with AIDS,
having progressive disseminated histoplasmosis should
initially be treated with IV liposomal amphotericin B until
clinical response and stabilization has been achieved.29
At that point, stable and improving patients may be
switched to oral itraconazole, 200 mg bid, until effective
immune reconstitution has been established, with the
CD41 counts rising above 200/mL. Patients who remain
immunosuppressed may require lifelong maintenance
therapy.25 For some immunocompromised patients with
severe pulmonary histoplasmosis and diffuse lung injury,
the addition of adjunctive glucocorticosteroid therapy at
a suggested dosage of prednisone of 40 to 60 mg/d for
1 to 2 weeks may be beneficial.1
For immunocompromised patients with mild to moderate pulmonary blastomycosis without evidence of
CNS involvement, oral itraconazole, 200 mg bid for at
least 12 months, can be used.1 However, in cases of
severe pulmonary blastomycosis without CNS involvement, again liposomal amphotericin B is required until
clinical improvement is definitively established, followed
by oral itraconazole therapy for at least 12 months.
Patients with AIDS require ongoing oral itraconazole,
200 mg/d, indefinitely or until immunity is well
reconstituted.
In patients with pulmonary blastomycosis and concurrent
CNS involvement, initial therapy with lipid formulations of amphotericin B (5 mg/kg/d) should also be
administered daily from the beginning of therapy until
clinical improvement is well established. Subsequently,
fluconazole is used for at least 12 months total after discontinuation of initial IV amphotericin B. Voriconazole,
200 mg bid, may be considered as an alternative to
fluconazole.1 Patients with AIDS having CNS disease
should continue to receive oral fluconazole, 400 mg/d,
indefinitely or until immunity is fully restored.
Coccidioidomycosis
Blastomycosis Infections
Blastomyces dermatidis, a dimorphic fungus endemic
in the central and southeast United States, causes
acute, subacute, and chronic lung infections. A limited
number of cases present with blastomycosis-associated
ARDS and fulminant diffuse pneumonia.30 More commonly, the manifestations are less severe, such as lobar
pneumonia, mass-like consolidative lesions, pulmonary
journal.publications.chestnet.org
Coccidioidomycosis is caused by inhalation of soildwelling Coccidioides immitis or C posadasii and has its
highest incidence in the San Joaquin Valley of California,
in south-central Arizona, and in northwestern Mexico.27
Many coccidioidal infections are minimally symptomatic.
However, some infections induce pulmonary symptoms
resembling community-acquired pneumonia. Acute
pulmonary coccidioidomycosis may be distinguished
1663
from bacterial community-acquired pneumonia by its
failure to respond to usual antibacterial therapy and by
associated hilar adenopathy, peripheral blood eosinophilia,
fatigue, night sweats, and skin lesions that include
erythema multiforme or erythema nodosum, in some
cases. Acute primary pulmonary coccidioidomycosis is
frequently self-limited, and most immunocompetent
patients with primary pulmonary coccidioidomycosis
and no risk factors for systemic dissemination do not
require treatment. However, risk factors for dissemination must be carefully assessed in each patient.27 These
risk factors are discussed in Table 3. In addition, certain
medical conditions place patients at higher risk for
severe pulmonary infections, including COPD and other
structural lung disease, renal failure, and congestive
heart failure.
coccidioidomycosis-related lung nodules in patients
with additional risk factors for disseminated disease, or
in cavitary disease with or without hemoptysis, treatment with either fluconazole or itraconazole is indicated. Azole therapy for chronic nodular or cavitary
pulmonary coccidioidomycosis with symptoms lasting
for . 3 months is generally prolonged for 12 to 18 months
or longer until the cavities and symptoms stabilize.27 In
cases of diffuse pulmonary coccidioidomycosis with
diffuse lung injury and gas-exchange impairment, initial amphotericin B is necessary to establish clinical
improvement.1 This is followed by fluconazole (400 mg/d)
or itraconazole (400 mg/d) for at least one additional
year. Patients have ongoing immunosuppression
require ongoing azole therapy until immune reconstitution occurs.
For immunocompetent patients with pulmonary coccidioidomycosis and moderate to severe symptoms, treatment
is usually initiated with either fluconazole (400 mg/d) or
itraconazole (400 mg/d) for at least 6 months, or even
longer if symptoms and radiographic abnormalities
persist.1 Posaconazole also has activity against coccidioidomycosis and is sometimes used in resistant cases.32
For patients with coccidioidomycosis-related pulmonary nodules alone, observation for at least 1 year without antifungal treatment can be undertaken. However,
either fluconazole or itraconazole may be administered
during periods of significant immunosuppression
(ie, chemotherapy, systemic corticosteroid therapy, or
CD4 counts , 200/mL).
Disseminated coccidioidomycosis with spread from the
lungs to bone, joints, skin, CNS, or elsewhere, whether
in immunocompetent or immunocompromised patients,
requires therapy. For nonmeningeal disseminated
disease, fluconazole (400 mg/d) or itraconazole (400 mg/d)
is administered for at least 1 year and until clinical stabilization.27 Itraconazole is preferred in the case of bone
or joint disease. In severe cases, IV liposomal amphotericin B should be initiated until clinical improvement,
followed by fluconazole (400 mg/d) or itraconazole
(400 mg/d) for at least another year. In patients presenting with neurologic symptoms with primary coccidioidomycosis, lumbar puncture is required to evaluate
for the possibility of Coccidioides species-induced meningitis. In patients with disseminated coccidioidomycosis and meningitis, initial liposomal amphotericin
therapy is followed by azole therapy such as fluconazole (800-1,000 mg/d), which may be necessary for
life, as these cases frequently relapse if therapy is
discontinued.1
Therapy for primary pulmonary coccidioidomycosis
should be considered for all patients with risk factors for
dissemination and for immunocompromised patients
(Table 3). Either fluconazole (400 mg/d) or itraconazole
(400 mg/d) would be appropriate in these cases. For
TABLE 3
] Risk Factors for Dissemination of
Coccidioidomycosis
Factors
Immunosuppressed patients
HIV/AIDS
Hematologic malignancies, including lymphoma
Chronic corticosteroid therapy
Treatment with immunosuppressing agents such as
tumor necrosis factor-a antagonists
Diabetes mellitus
Third trimester of pregnancy
Male sex
Patients of black or Filipino descent
1664 Recent Advances in Chest Medicine
Therapeutic Options for Aspergillosis
Treatment approaches for Aspergillus species lung
disease depend upon the setting, immunocompetence,
and tempo of disease. For instance, aspergillomas represent a mycetomatous colonization of preexisting cavitary
spaces in the lung, with such lesions having a significant
tendency for bleeding. In the setting of significant
bleeding, interventional radiology with embolization
can be life saving. Surgical management of fungus balls
does have relatively high associated morbidity and
mortality. However, there are still selective cases where
surgical resection becomes a necessity. On occasion,
aspergillomas can proceed into chronic necrotizing aspergillosis if patients are immunosuppressed.
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Significant invasive Aspergillus species pneumonia only
occurs in immunosuppressed hosts, generally in those
with neutropenia, significant corticosteroid exposure, or
cytotoxic chemotherapy. Current firstline therapy for
invasive Aspergillus pneumonia is based on IV voriconazole therapy (6 mg/kg q12h) for the first day, followed
by 4 mg/kg IV q12h until improvement.33 After stabilization, therapy can be switched to oral voriconazole,
200 mg q12h, until the lesion resolves. Alternatively,
IV liposomal amphotericin B can be used (3-5 mg/kg/d)
until the patient improves, followed by oral voriconazole, 200 mg q12h.1 Whenever possible, reversal of
immunosuppression will often be necessary for therapy
to be effective. In patients with invasive pulmonary
aspergillosis who fail initial therapy, an echinocandin
such as IV caspofungin (70 mg on day 1 and 50 mg/d
thereafter) may be used as salvage therapy. There are
not definitive data documenting additive benefit from
echinocandins administered concurrently with voriconazole.34 In addition, oral posaconazole may also be
attempted as a salvage strategy.35 In selected patients
with refractory, focal, invasive pulmonary aspergillosis
failing aggressive therapy, surgical excision may also be
considered.
Management of chronic necrotizing aspergillosis (“minimally invasive” disease) requires individualization based
upon disease severity and the relative immunocompetency of the host. In patients with mild to moderate
infection, oral voriconazole or itraconazole may be
attempted until clinical stabilization occurs. In patients
with more severe disease, initial therapy with either
IV voriconazole or liposomal amphotericin B may be
considered.1 Once again, surgical resection may be
needed in selected cases, based upon severity, extent of
infection (focal vs diffuse), and initial responses to antifungal therapy.
Conclusions
Studies indicate increasing populations of patients
susceptible to fungal lung infections.24,36 A high index
of suspicion is necessary to detect invasive fungal infection in immunocompromised patients. Appropriate
application of available diagnostic testing and rapid implementation of therapy are necessary to secure optimal
clinical response.
Acknowledgments
Financial/nonfinancial disclosures: The author has reported to CHEST
that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.
journal.publications.chestnet.org
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