Quiz: Systemic Fungal Diseases

Itraconazole is an oral triazole antifungal drug that acts by altering the cell membrane of susceptible fungi, including B dermatitidis. Success rates between 53.6%¹ and 90%² have been reported. In a study comparing the efficacy of fluconazole (another oral azole) with that of itraconazole in the treatment of canine blastomycosis, no difference in remission rates (fluconazole 75% remission, itraconazole 90% remission) was identified, although the authors noted that statistical significance may have been achieved with a larger sample size.² Therefore, fluconazole was not included as a treatment option because the treatment choice between itraconazole and fluconazole is often based on clinician preference.

Ketoconazole alone is less effective than amphotericin B.³ In a retrospective study, itraconazole was as effective as amphotericin B and ketoconazole.⁴ As compared with amphotericin B, itraconazole is easier to administer and has fewer side effects. Amphotericin B is effective in treating canine blastomycosis but has to be administered by IV and is nephrotoxic.⁵

Miconazole is used as topical therapy⁶ but has not been reported for systemic treatment of blastomycosis.

Flucytosine has little or no efficacy against B dermatitidis infection.⁷ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is A.

Itraconazole is an oral triazole antifungal drug that acts by altering the cell membrane of susceptible fungi, including B dermatitidis. Success rates between 53.6%¹ and 90%² have been reported. In a study comparing the efficacy of fluconazole (another oral azole) with that of itraconazole in the treatment of canine blastomycosis, no difference in remission rates (fluconazole 75% remission, itraconazole 90% remission) was identified, although the authors noted that statistical significance may have been achieved with a larger sample size.² Therefore, fluconazole was not included as a treatment option because the treatment choice between itraconazole and fluconazole is often based on clinician preference.

Ketoconazole alone is less effective than amphotericin B.³ In a retrospective study, itraconazole was as effective as amphotericin B and ketoconazole.⁴ As compared with amphotericin B, itraconazole is easier to administer and has fewer side effects. Amphotericin B is effective in treating canine blastomycosis but has to be administered by IV and is nephrotoxic.⁵

Miconazole is used as topical therapy⁶ but has not been reported for systemic treatment of blastomycosis.

Flucytosine has little or no efficacy against B dermatitidis infection.⁷ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is A.

Itraconazole is an oral triazole antifungal drug that acts by altering the cell membrane of susceptible fungi, including B dermatitidis. Success rates between 53.6%¹ and 90%² have been reported. In a study comparing the efficacy of fluconazole (another oral azole) with that of itraconazole in the treatment of canine blastomycosis, no difference in remission rates (fluconazole 75% remission, itraconazole 90% remission) was identified, although the authors noted that statistical significance may have been achieved with a larger sample size.² Therefore, fluconazole was not included as a treatment option because the treatment choice between itraconazole and fluconazole is often based on clinician preference.

Ketoconazole alone is less effective than amphotericin B.³ In a retrospective study, itraconazole was as effective as amphotericin B and ketoconazole.⁴ As compared with amphotericin B, itraconazole is easier to administer and has fewer side effects. Amphotericin B is effective in treating canine blastomycosis but has to be administered by IV and is nephrotoxic.⁵

Miconazole is used as topical therapy⁶ but has not been reported for systemic treatment of blastomycosis.

Flucytosine has little or no efficacy against B dermatitidis infection.⁷ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is A.

Itraconazole is an oral triazole antifungal drug that acts by altering the cell membrane of susceptible fungi, including B dermatitidis. Success rates between 53.6%¹ and 90%² have been reported. In a study comparing the efficacy of fluconazole (another oral azole) with that of itraconazole in the treatment of canine blastomycosis, no difference in remission rates (fluconazole 75% remission, itraconazole 90% remission) was identified, although the authors noted that statistical significance may have been achieved with a larger sample size.² Therefore, fluconazole was not included as a treatment option because the treatment choice between itraconazole and fluconazole is often based on clinician preference.

Ketoconazole alone is less effective than amphotericin B.³ In a retrospective study, itraconazole was as effective as amphotericin B and ketoconazole.⁴ As compared with amphotericin B, itraconazole is easier to administer and has fewer side effects. Amphotericin B is effective in treating canine blastomycosis but has to be administered by IV and is nephrotoxic.⁵

Miconazole is used as topical therapy⁶ but has not been reported for systemic treatment of blastomycosis.

Flucytosine has little or no efficacy against B dermatitidis infection.⁷ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is A.

Itraconazole is an oral triazole antifungal drug that acts by altering the cell membrane of susceptible fungi, including B dermatitidis. Success rates between 53.6%¹ and 90%² have been reported. In a study comparing the efficacy of fluconazole (another oral azole) with that of itraconazole in the treatment of canine blastomycosis, no difference in remission rates (fluconazole 75% remission, itraconazole 90% remission) was identified, although the authors noted that statistical significance may have been achieved with a larger sample size.² Therefore, fluconazole was not included as a treatment option because the treatment choice between itraconazole and fluconazole is often based on clinician preference.

Ketoconazole alone is less effective than amphotericin B.³ In a retrospective study, itraconazole was as effective as amphotericin B and ketoconazole.⁴ As compared with amphotericin B, itraconazole is easier to administer and has fewer side effects. Amphotericin B is effective in treating canine blastomycosis but has to be administered by IV and is nephrotoxic.⁵

Miconazole is used as topical therapy⁶ but has not been reported for systemic treatment of blastomycosis.

Flucytosine has little or no efficacy against B dermatitidis infection.⁷ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is E.

At body temperature, Blastomyces spp organisms transform into their yeast form. Because the yeast form is too large to enter terminal airways as an aerosol, transmission by aerosolized yeast is not considered to occur. 

In nature, Blastomyces spp grow in a mycelial form that produces infective spores. Infection occurs via inhalation of these spores into the lungs. Although uncommon, blastomycosis has developed in humans following a bite by an infected dog. Accidental inoculation by objects contaminated with organisms (eg, needles, necropsy knives) has resulted in infection in humans. The organism should only be cultured in a laboratory with special facilities, as growth of the mycelial form can result in exposure of personnel to infectious spores.⁵ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is E.

At body temperature, Blastomyces spp organisms transform into their yeast form. Because the yeast form is too large to enter terminal airways as an aerosol, transmission by aerosolized yeast is not considered to occur. 

In nature, Blastomyces spp grow in a mycelial form that produces infective spores. Infection occurs via inhalation of these spores into the lungs. Although uncommon, blastomycosis has developed in humans following a bite by an infected dog. Accidental inoculation by objects contaminated with organisms (eg, needles, necropsy knives) has resulted in infection in humans. The organism should only be cultured in a laboratory with special facilities, as growth of the mycelial form can result in exposure of personnel to infectious spores.⁵ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is E.

At body temperature, Blastomyces spp organisms transform into their yeast form. Because the yeast form is too large to enter terminal airways as an aerosol, transmission by aerosolized yeast is not considered to occur. 

In nature, Blastomyces spp grow in a mycelial form that produces infective spores. Infection occurs via inhalation of these spores into the lungs. Although uncommon, blastomycosis has developed in humans following a bite by an infected dog. Accidental inoculation by objects contaminated with organisms (eg, needles, necropsy knives) has resulted in infection in humans. The organism should only be cultured in a laboratory with special facilities, as growth of the mycelial form can result in exposure of personnel to infectious spores.⁵ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is E.

At body temperature, Blastomyces spp organisms transform into their yeast form. Because the yeast form is too large to enter terminal airways as an aerosol, transmission by aerosolized yeast is not considered to occur. 

In nature, Blastomyces spp grow in a mycelial form that produces infective spores. Infection occurs via inhalation of these spores into the lungs. Although uncommon, blastomycosis has developed in humans following a bite by an infected dog. Accidental inoculation by objects contaminated with organisms (eg, needles, necropsy knives) has resulted in infection in humans. The organism should only be cultured in a laboratory with special facilities, as growth of the mycelial form can result in exposure of personnel to infectious spores.⁵ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

At body temperature, Blastomyces spp organisms transform into their yeast form. Because the yeast form is too large to enter terminal airways as an aerosol, transmission by aerosolized yeast is not considered to occur. 

In nature, Blastomyces spp grow in a mycelial form that produces infective spores. Infection occurs via inhalation of these spores into the lungs. Although uncommon, blastomycosis has developed in humans following a bite by an infected dog. Accidental inoculation by objects contaminated with organisms (eg, needles, necropsy knives) has resulted in infection in humans. The organism should only be cultured in a laboratory with special facilities, as growth of the mycelial form can result in exposure of personnel to infectious spores.⁵ 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is D.

In humans, Histoplasma spp infections may be evident in examination of urine sediment,⁸ but Histoplasma spp have not been reported in feline urine. In a case report of disseminated histoplasmosis involving the wall of the urinary bladder of a cat, examination of urine sediment revealed hematuria and pyuria without visible organisms.⁹

In cats, H capsulatum organisms are most often found on cytology of bone marrow, lung, and lymph node aspirates. Less commonly, organisms can be found in impression smears of discharge from skin lesions. H capsulatum organisms may also be found during examination of a peripheral blood smear.⁸

The correct answer is D.

In humans, Histoplasma spp infections may be evident in examination of urine sediment,⁸ but Histoplasma spp have not been reported in feline urine. In a case report of disseminated histoplasmosis involving the wall of the urinary bladder of a cat, examination of urine sediment revealed hematuria and pyuria without visible organisms.⁹

In cats, H capsulatum organisms are most often found on cytology of bone marrow, lung, and lymph node aspirates. Less commonly, organisms can be found in impression smears of discharge from skin lesions. H capsulatum organisms may also be found during examination of a peripheral blood smear.⁸

The correct answer is D.

In humans, Histoplasma spp infections may be evident in examination of urine sediment,⁸ but Histoplasma spp have not been reported in feline urine. In a case report of disseminated histoplasmosis involving the wall of the urinary bladder of a cat, examination of urine sediment revealed hematuria and pyuria without visible organisms.⁹

In cats, H capsulatum organisms are most often found on cytology of bone marrow, lung, and lymph node aspirates. Less commonly, organisms can be found in impression smears of discharge from skin lesions. H capsulatum organisms may also be found during examination of a peripheral blood smear.⁸

In humans, Histoplasma spp infections may be evident in examination of urine sediment,⁸ but Histoplasma spp have not been reported in feline urine. In a case report of disseminated histoplasmosis involving the wall of the urinary bladder of a cat, examination of urine sediment revealed hematuria and pyuria without visible organisms.⁹

In cats, H capsulatum organisms are most often found on cytology of bone marrow, lung, and lymph node aspirates. Less commonly, organisms can be found in impression smears of discharge from skin lesions. H capsulatum organisms may also be found during examination of a peripheral blood smear.⁸

The correct answer is D.

In humans, Histoplasma spp infections may be evident in examination of urine sediment,⁸ but Histoplasma spp have not been reported in feline urine. In a case report of disseminated histoplasmosis involving the wall of the urinary bladder of a cat, examination of urine sediment revealed hematuria and pyuria without visible organisms.⁹

In cats, H capsulatum organisms are most often found on cytology of bone marrow, lung, and lymph node aspirates. Less commonly, organisms can be found in impression smears of discharge from skin lesions. H capsulatum organisms may also be found during examination of a peripheral blood smear.⁸

The correct answer is B. 

In nature, H capsulatum grows as a mycelial form that produces spores called macroconidia and microconidia. Feline infections are thought to occur via inhalation of microconidia, which are small enough to reach the lower respiratory tract (as opposed to the larger macroconidia, which cannot). Cutaneous and GI infections have been reported without evidence of systemic involvement; although the skin and GI tract may be primary sites of infection, they are not main routes of infection. In tissues, H capsulatum convert to the yeast phase; direct transmission between animals has not been reported.⁸

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

In nature, H capsulatum grows as a mycelial form that produces spores called macroconidia and microconidia. Feline infections are thought to occur via inhalation of microconidia, which are small enough to reach the lower respiratory tract (as opposed to the larger macroconidia, which cannot). Cutaneous and GI infections have been reported without evidence of systemic involvement; although the skin and GI tract may be primary sites of infection, they are not main routes of infection. In tissues, H capsulatum convert to the yeast phase; direct transmission between animals has not been reported.⁸

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B. 

In nature, H capsulatum grows as a mycelial form that produces spores called macroconidia and microconidia. Feline infections are thought to occur via inhalation of microconidia, which are small enough to reach the lower respiratory tract (as opposed to the larger macroconidia, which cannot). Cutaneous and GI infections have been reported without evidence of systemic involvement; although the skin and GI tract may be primary sites of infection, they are not main routes of infection. In tissues, H capsulatum convert to the yeast phase; direct transmission between animals has not been reported.⁸

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B. 

In nature, H capsulatum grows as a mycelial form that produces spores called macroconidia and microconidia. Feline infections are thought to occur via inhalation of microconidia, which are small enough to reach the lower respiratory tract (as opposed to the larger macroconidia, which cannot). Cutaneous and GI infections have been reported without evidence of systemic involvement; although the skin and GI tract may be primary sites of infection, they are not main routes of infection. In tissues, H capsulatum convert to the yeast phase; direct transmission between animals has not been reported.⁸

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B. 

In nature, H capsulatum grows as a mycelial form that produces spores called macroconidia and microconidia. Feline infections are thought to occur via inhalation of microconidia, which are small enough to reach the lower respiratory tract (as opposed to the larger macroconidia, which cannot). Cutaneous and GI infections have been reported without evidence of systemic involvement; although the skin and GI tract may be primary sites of infection, they are not main routes of infection. In tissues, H capsulatum convert to the yeast phase; direct transmission between animals has not been reported.⁸

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is E.

Urine and serum antigen testing can be used to guide therapy.¹¹ Both decrease over time with effective treatment. Negative urine antigen testing has a sensitivity of 90% and specificity of 64.6% when compared to clinical remission. Negative serum antigen testing has a sensitivity of 90.4% and specificity of 52.1%. Urine antigen became positive in 2 cats that experienced relapse.¹²

The correct answer is E.

Urine and serum antigen testing can be used to guide therapy.¹¹ Both decrease over time with effective treatment. Negative urine antigen testing has a sensitivity of 90% and specificity of 64.6% when compared to clinical remission. Negative serum antigen testing has a sensitivity of 90.4% and specificity of 52.1%. Urine antigen became positive in 2 cats that experienced relapse.¹²

The correct answer is E.

Urine and serum antigen testing can be used to guide therapy.¹¹ Both decrease over time with effective treatment. Negative urine antigen testing has a sensitivity of 90% and specificity of 64.6% when compared to clinical remission. Negative serum antigen testing has a sensitivity of 90.4% and specificity of 52.1%. Urine antigen became positive in 2 cats that experienced relapse.¹²

The correct answer is E.

Urine and serum antigen testing can be used to guide therapy.¹¹ Both decrease over time with effective treatment. Negative urine antigen testing has a sensitivity of 90% and specificity of 64.6% when compared to clinical remission. Negative serum antigen testing has a sensitivity of 90.4% and specificity of 52.1%. Urine antigen became positive in 2 cats that experienced relapse.¹²

Urine and serum antigen testing can be used to guide therapy.¹¹ Both decrease over time with effective treatment. Negative urine antigen testing has a sensitivity of 90% and specificity of 64.6% when compared to clinical remission. Negative serum antigen testing has a sensitivity of 90.4% and specificity of 52.1%. Urine antigen became positive in 2 cats that experienced relapse.¹²

The correct answer is C.

Fever is very rare in cats with Cryptococcus spp infection. However, weight loss with a poor appetite is common, as are upper respiratory tract signs, including sneezing and mucopurulent, serous, or hemorrhagic nasal discharge. In some cats, firm-to-fluctuant swelling can develop over the bridge of the nose.¹³

The correct answer is C.

Fever is very rare in cats with Cryptococcus spp infection. However, weight loss with a poor appetite is common, as are upper respiratory tract signs, including sneezing and mucopurulent, serous, or hemorrhagic nasal discharge. In some cats, firm-to-fluctuant swelling can develop over the bridge of the nose.¹³

Fever is very rare in cats with Cryptococcus spp infection. However, weight loss with a poor appetite is common, as are upper respiratory tract signs, including sneezing and mucopurulent, serous, or hemorrhagic nasal discharge. In some cats, firm-to-fluctuant swelling can develop over the bridge of the nose.¹³

The correct answer is C.

Fever is very rare in cats with Cryptococcus spp infection. However, weight loss with a poor appetite is common, as are upper respiratory tract signs, including sneezing and mucopurulent, serous, or hemorrhagic nasal discharge. In some cats, firm-to-fluctuant swelling can develop over the bridge of the nose.¹³

The correct answer is C.

Fever is very rare in cats with Cryptococcus spp infection. However, weight loss with a poor appetite is common, as are upper respiratory tract signs, including sneezing and mucopurulent, serous, or hemorrhagic nasal discharge. In some cats, firm-to-fluctuant swelling can develop over the bridge of the nose.¹³

There is no correlation between absolute pretreatment antigen titer and outcome.¹³ False-negative and false-positive results may occur when measuring cryptococcal polysaccharide capsular antigen by latex agglutination. False-negative results are more common with localized ocular, neurologic, or cutaneous involvement.¹³ An antigen titer as low as 1:2 can indicate Cryptococcus spp infection, but higher titers (up to 1:200) have been reported in cats without confirmed infection.¹⁴ A persistent titer after treatment can suggest continued infection, but a decrease in titer may lag behind clinical improvement.¹³ This test is advantageous when collection of CSF may be risky and CNS cryptococcosis is suspected.¹³

The correct answer is A.

There is no correlation between absolute pretreatment antigen titer and outcome.¹³ False-negative and false-positive results may occur when measuring cryptococcal polysaccharide capsular antigen by latex agglutination. False-negative results are more common with localized ocular, neurologic, or cutaneous involvement.¹³ An antigen titer as low as 1:2 can indicate Cryptococcus spp infection, but higher titers (up to 1:200) have been reported in cats without confirmed infection.¹⁴ A persistent titer after treatment can suggest continued infection, but a decrease in titer may lag behind clinical improvement.¹³ This test is advantageous when collection of CSF may be risky and CNS cryptococcosis is suspected.¹³

The correct answer is A.

There is no correlation between absolute pretreatment antigen titer and outcome.¹³ False-negative and false-positive results may occur when measuring cryptococcal polysaccharide capsular antigen by latex agglutination. False-negative results are more common with localized ocular, neurologic, or cutaneous involvement.¹³ An antigen titer as low as 1:2 can indicate Cryptococcus spp infection, but higher titers (up to 1:200) have been reported in cats without confirmed infection.¹⁴ A persistent titer after treatment can suggest continued infection, but a decrease in titer may lag behind clinical improvement.¹³ This test is advantageous when collection of CSF may be risky and CNS cryptococcosis is suspected.¹³

The correct answer is A.

There is no correlation between absolute pretreatment antigen titer and outcome.¹³ False-negative and false-positive results may occur when measuring cryptococcal polysaccharide capsular antigen by latex agglutination. False-negative results are more common with localized ocular, neurologic, or cutaneous involvement.¹³ An antigen titer as low as 1:2 can indicate Cryptococcus spp infection, but higher titers (up to 1:200) have been reported in cats without confirmed infection.¹⁴ A persistent titer after treatment can suggest continued infection, but a decrease in titer may lag behind clinical improvement.¹³ This test is advantageous when collection of CSF may be risky and CNS cryptococcosis is suspected.¹³

The correct answer is A.

There is no correlation between absolute pretreatment antigen titer and outcome.¹³ False-negative and false-positive results may occur when measuring cryptococcal polysaccharide capsular antigen by latex agglutination. False-negative results are more common with localized ocular, neurologic, or cutaneous involvement.¹³ An antigen titer as low as 1:2 can indicate Cryptococcus spp infection, but higher titers (up to 1:200) have been reported in cats without confirmed infection.¹⁴ A persistent titer after treatment can suggest continued infection, but a decrease in titer may lag behind clinical improvement.¹³ This test is advantageous when collection of CSF may be risky and CNS cryptococcosis is suspected.¹³

The correct answer is D.

Amphotericin B is the most effective anticryptococcal agent and fungicidal.  A combination of amphotericin B and flucytosine is often considered the treatment of choice for feline cryptococcosis, especially in patients with CNS involvement. Flucytosine is synergistic with amphotericin B.¹³ Flucytosine inhibits DNA synthesis in yeasts by interfering with pyrimidine metabolism.⁷ Resistance develops readily, so flucytosine is always given with amphotericin B or an azole.¹³

Monotherapy with fluconazole is also effective in the treatment of cryptococcosis, is less expensive, can be administered orally, and is not nephrotoxic. However, fluconazole is fungistatic. Fluconazole (with or without amphotericin B) may be a suitable alternative to amphotericin B with flucytosine.¹³ 

Griseofulvin, an oral antifungal with limited spectrum of activity, is used primarily in the treatment of dermatophytosis.¹⁵ Clotrimazole and enilconazole are used as topical treatment of nasal Aspergillus spp infection; their spectrum of coverage does not include Cryptococcus spp.^16,17 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is D.

Amphotericin B is the most effective anticryptococcal agent and fungicidal.  A combination of amphotericin B and flucytosine is often considered the treatment of choice for feline cryptococcosis, especially in patients with CNS involvement. Flucytosine is synergistic with amphotericin B.¹³ Flucytosine inhibits DNA synthesis in yeasts by interfering with pyrimidine metabolism.⁷ Resistance develops readily, so flucytosine is always given with amphotericin B or an azole.¹³

Monotherapy with fluconazole is also effective in the treatment of cryptococcosis, is less expensive, can be administered orally, and is not nephrotoxic. However, fluconazole is fungistatic. Fluconazole (with or without amphotericin B) may be a suitable alternative to amphotericin B with flucytosine.¹³ 

Griseofulvin, an oral antifungal with limited spectrum of activity, is used primarily in the treatment of dermatophytosis.¹⁵ Clotrimazole and enilconazole are used as topical treatment of nasal Aspergillus spp infection; their spectrum of coverage does not include Cryptococcus spp.^16,17 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is D.

Amphotericin B is the most effective anticryptococcal agent and fungicidal.  A combination of amphotericin B and flucytosine is often considered the treatment of choice for feline cryptococcosis, especially in patients with CNS involvement. Flucytosine is synergistic with amphotericin B.¹³ Flucytosine inhibits DNA synthesis in yeasts by interfering with pyrimidine metabolism.⁷ Resistance develops readily, so flucytosine is always given with amphotericin B or an azole.¹³

Monotherapy with fluconazole is also effective in the treatment of cryptococcosis, is less expensive, can be administered orally, and is not nephrotoxic. However, fluconazole is fungistatic. Fluconazole (with or without amphotericin B) may be a suitable alternative to amphotericin B with flucytosine.¹³ 

Griseofulvin, an oral antifungal with limited spectrum of activity, is used primarily in the treatment of dermatophytosis.¹⁵ Clotrimazole and enilconazole are used as topical treatment of nasal Aspergillus spp infection; their spectrum of coverage does not include Cryptococcus spp.^16,17 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

Amphotericin B is the most effective anticryptococcal agent and fungicidal.  A combination of amphotericin B and flucytosine is often considered the treatment of choice for feline cryptococcosis, especially in patients with CNS involvement. Flucytosine is synergistic with amphotericin B.¹³ Flucytosine inhibits DNA synthesis in yeasts by interfering with pyrimidine metabolism.⁷ Resistance develops readily, so flucytosine is always given with amphotericin B or an azole.¹³

Monotherapy with fluconazole is also effective in the treatment of cryptococcosis, is less expensive, can be administered orally, and is not nephrotoxic. However, fluconazole is fungistatic. Fluconazole (with or without amphotericin B) may be a suitable alternative to amphotericin B with flucytosine.¹³ 

Griseofulvin, an oral antifungal with limited spectrum of activity, is used primarily in the treatment of dermatophytosis.¹⁵ Clotrimazole and enilconazole are used as topical treatment of nasal Aspergillus spp infection; their spectrum of coverage does not include Cryptococcus spp.^16,17 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is D.

Amphotericin B is the most effective anticryptococcal agent and fungicidal.  A combination of amphotericin B and flucytosine is often considered the treatment of choice for feline cryptococcosis, especially in patients with CNS involvement. Flucytosine is synergistic with amphotericin B.¹³ Flucytosine inhibits DNA synthesis in yeasts by interfering with pyrimidine metabolism.⁷ Resistance develops readily, so flucytosine is always given with amphotericin B or an azole.¹³

Monotherapy with fluconazole is also effective in the treatment of cryptococcosis, is less expensive, can be administered orally, and is not nephrotoxic. However, fluconazole is fungistatic. Fluconazole (with or without amphotericin B) may be a suitable alternative to amphotericin B with flucytosine.¹³ 

Griseofulvin, an oral antifungal with limited spectrum of activity, is used primarily in the treatment of dermatophytosis.¹⁵ Clotrimazole and enilconazole are used as topical treatment of nasal Aspergillus spp infection; their spectrum of coverage does not include Cryptococcus spp.^16,17 

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B.

A longitudinal study of 104 dogs from two counties in Arizona evaluated risk factors for infection with Coccidioides spp and found no difference between female and male dogs.¹⁸ As compared with dogs that were housed predominantly indoors, outdoor dogs and dogs that roamed were at increased risk.¹⁸ Periods of heavy rainfall or dust storms that disrupt the soil have been associated with increased risk for infection.¹⁹

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

A longitudinal study of 104 dogs from two counties in Arizona evaluated risk factors for infection with Coccidioides spp and found no difference between female and male dogs.¹⁸ As compared with dogs that were housed predominantly indoors, outdoor dogs and dogs that roamed were at increased risk.¹⁸ Periods of heavy rainfall or dust storms that disrupt the soil have been associated with increased risk for infection.¹⁹

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B.

A longitudinal study of 104 dogs from two counties in Arizona evaluated risk factors for infection with Coccidioides spp and found no difference between female and male dogs.¹⁸ As compared with dogs that were housed predominantly indoors, outdoor dogs and dogs that roamed were at increased risk.¹⁸ Periods of heavy rainfall or dust storms that disrupt the soil have been associated with increased risk for infection.¹⁹

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B.

A longitudinal study of 104 dogs from two counties in Arizona evaluated risk factors for infection with Coccidioides spp and found no difference between female and male dogs.¹⁸ As compared with dogs that were housed predominantly indoors, outdoor dogs and dogs that roamed were at increased risk.¹⁸ Periods of heavy rainfall or dust storms that disrupt the soil have been associated with increased risk for infection.¹⁹

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

The correct answer is B.

A longitudinal study of 104 dogs from two counties in Arizona evaluated risk factors for infection with Coccidioides spp and found no difference between female and male dogs.¹⁸ As compared with dogs that were housed predominantly indoors, outdoor dogs and dogs that roamed were at increased risk.¹⁸ Periods of heavy rainfall or dust storms that disrupt the soil have been associated with increased risk for infection.¹⁹

Images courtesy of Dr. Annalisa Hernandez, Texas A&M University Clinical Pathology Department in College Station

Immunoglobulin M (IgM) is detectable within 2 to 5 weeks after C immitis infection. IgG appears after 8 to 12 weeks.¹⁹ While negative IgM and IgG titers usually indicate lack of exposure, this result can occasionally occur very early in an infection and thus cannot completely exclude infection.²⁰ Early after exposure, the IgM titer may be positive while IgG is negative. Later, the IgM result will decline and thus patients with low IgG titers (especially <1:4) likely had previous exposure or disease. IgG titers >1:64 are most frequently seen in patients with disseminated infection. Titers often decline after treatment, but weak positive results for IgG often persist.²⁰

The correct answer is A.

Immunoglobulin M (IgM) is detectable within 2 to 5 weeks after C immitis infection. IgG appears after 8 to 12 weeks.¹⁹ While negative IgM and IgG titers usually indicate lack of exposure, this result can occasionally occur very early in an infection and thus cannot completely exclude infection.²⁰ Early after exposure, the IgM titer may be positive while IgG is negative. Later, the IgM result will decline and thus patients with low IgG titers (especially <1:4) likely had previous exposure or disease. IgG titers >1:64 are most frequently seen in patients with disseminated infection. Titers often decline after treatment, but weak positive results for IgG often persist.²⁰

The correct answer is A.

Immunoglobulin M (IgM) is detectable within 2 to 5 weeks after C immitis infection. IgG appears after 8 to 12 weeks.¹⁹ While negative IgM and IgG titers usually indicate lack of exposure, this result can occasionally occur very early in an infection and thus cannot completely exclude infection.²⁰ Early after exposure, the IgM titer may be positive while IgG is negative. Later, the IgM result will decline and thus patients with low IgG titers (especially <1:4) likely had previous exposure or disease. IgG titers >1:64 are most frequently seen in patients with disseminated infection. Titers often decline after treatment, but weak positive results for IgG often persist.²⁰

The correct answer is A.

Immunoglobulin M (IgM) is detectable within 2 to 5 weeks after C immitis infection. IgG appears after 8 to 12 weeks.¹⁹ While negative IgM and IgG titers usually indicate lack of exposure, this result can occasionally occur very early in an infection and thus cannot completely exclude infection.²⁰ Early after exposure, the IgM titer may be positive while IgG is negative. Later, the IgM result will decline and thus patients with low IgG titers (especially <1:4) likely had previous exposure or disease. IgG titers >1:64 are most frequently seen in patients with disseminated infection. Titers often decline after treatment, but weak positive results for IgG often persist.²⁰