cc: cough, fever, dyspnea and wart-like growth on neckHPI: 35-year old otherwise healthy, nonsmoker, male presents to

the clinic with complaints of intermittent cough, low-grade fever, and difficulty breathing that has persisted for the past few months. Additionally, he has noticed a nontender wart-like growth on his neck that has increased in size over this period. He reports 5 lb weight loss and has experienced some occasional joint stiffness throughout the day. He drinks 2-3 beers a week, tried marijuana 5 years ago, and denies any IV drug use or time spent in jail. He has worked as a landscaper for the past 10 years and recently moved from Missouri.

Physical Exam

vs: temp-38.6°C (101.5°F), BP-128/82, HR-98, RR-20

General-no acute distressHEENT-normocephalic atraumaticNeck-supple, no thyromegaly, no cervical lymphadenopathyCV-tachycardic, regular rhythm, normal S1/S2, no murmurs, rubs, or

gallopsPulmonary-bilateral fine inspiratory cracklesAbdomen-soft, nontender, nondistended, + BS, no hepatosplenomegalyExtremities-no cyanosis, clubbing, or edemaSkin-4-5 cm raised, nontender, verrucous like lesion located on right side

of neck just behind the ear

Physical Exam: Skin findings

Differential Diagnosis?

Differential DiagnosisPulmonary symptoms• Blastomycosis• Histoplasmosis• community acquired bacterial or viral pneumonia• Lung malignancy• TuberculosisCutaneous lesion• squamous cell carcinoma• pyoderma gangrenosum• keratoacanthoma• mycosis fungoides• actinomycosis

What labs/imaging would you like to order?

Labs:• CBC, electrolytes • ALT/AST/alkaline phosphatase/bilirubin• BUN/SCr• UA• PPD• Sputum sample and culture• Lesion biopsy

Imaging:• CXR

WBC 11,000/µLHemoglobin 10.9 g/dLPlatelet count 230,000/µL

Sodium 140 meq/LPotassium 4.1 meq/LChloride 95 meq/LBicarbonate 23 meq/LBUN 18 mg/dLCreatinine 1 mg/dL

ALT/AST/alk phos/bilirubin normal

Urinalysis normalPPD negative

Sputum broad-based budding yeastLesion bx noncaseating granuloma

Lab Results

Results: Imaging-CXR

What is your diagnosis?

Blastomycosis

• Is a systemic pyogranulomatous infection• Acquired through inhalation of the conidia of the

thermally dimorphic fungus, Blastomyces dermatitidis.• Lungs are most commonly affected, though almost

every organ may become involved through hematogenous dissemination

• May be an asymptomatic infection or develop into an acute or chronic pneumonia

BlastomycosisEpidemiology:• Most cases reported in North America• Endemic areas include southeastern and south-central

states bordering the Mississippi and Ohio River basins as well as the Great Lakes area.

• Annual incidence 40/100,000 in endemic areas• In endemic areas middle-aged men with outdoor

occupations at greatest risk• Exposure to ground soil associated with infection

BlastomycosisEtiology:• Blastomyces dermatitidis• There are 2 serotypes based on the presence or

absence of A antigen• Exhibits thermal dimorphism, mycelial phase at room

temp and yeast phase at 37°C.• Yeast cells are usually 8-15µm in diameter, have thick

refractile cell walls, and are multinucleate• Reproduce by single, large, broad-based bud.

Blastomycosis

1

1

2

2

1. Broad-based budding yeasts

2. Thick, double refractile cell wall

BlastomycosisPathophysiology:• Infection begins with inhalation of Blastomyces dermatitidis• Conidia may be killed through phagocytosis by

polymorphonuclear leukocytes, monocytes, and alveolar macrophages

• If conidia, the infectious stage, is not killed it may convert to the yeast phase in the tissue

• Yeast form is more resistant to phagocytosis and killing due to its size and thick cell wall thereby contributing to infection

• Primary acquired host defense against B. dermatitidis is cellular immunity mediated by antigen-specific T cells and activated macrophages.

Blastomycosis

Extrapulmonary manifestations:1. skin-second most common manifestation after pneumonia,

characteristic finding is verrucous lesion, with irregular border. It may look similar to squamous cell carcinoma.

2. Bone and joint-osteomyelitis3. Genitourinary system-prostatitis, epididymoorchitis, asymptomatic

pyuria4. CNS-uncommon in immunocompetent hosts; however, those that are

immunocompromised it may present as meningitis, epidural abscess, or intracranial abscess

*Blastomycosis has also been reported in lymph nodes, liver, spleen, breast, adrenal gland, thyroid, eye, and oral mucosa

BlastomycosisExamples of extrapulmonary manifestations:

1 2 3 4

5

1 2 33

4

51,3. Cutaneous Blastomycosis2. Blastomyces osteolytic

lesion4. CNS Blastomycosis5. Intramuscular

Blastomycosis

BlastomycosisTreatment:• Therapeutic regimen should be based on the clinical

form and severity of disease, and the immune status of patient.

• Immunocompetent patient with mild to moderate pulmonary or non-CNS disease-treat with itraconazole for 6-12 months

• Immunocompromised, CNS disease, or continued disease progression with itraconazole -treat with Amphotericin B

BlastomycosisFollow-up:• Monitor patient several years for relapse

Prognosis:• Treatment with itraconazole in immunocompetent

patient results in approx 90-95% response rate• Infections that relapse after initial itraconazole course

typically respond well to 2nd treatment course.

References:1 "Blastomycosis." Quick Answers to Medical Diagnosis and Therapy:

http://www.accessmedicine.com/quickam.aspx2 Chapman S.W., Sullivan D.C. (2012). Chapter 201. Blastomycosis. In D.L.

Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e. Retrieved November 21, 2012 from http://www.accessmedicine.com/content.aspx?aID=9110719.

3 Bradsher Jr., RW. Clinical manifestations and diagnosis of blastomycosis. In: UpToDate, Kauffman, C, Thorner, A, eds. UpToDate, Waltham, MA, 2012

4 Bradsher Jr., RW. Treatment of blastomycosis. In: UpToDate, Kauffman, C, Thorner, A, eds. UpToDate, Waltham, MA, 2012

5 Centers for Disease Control and Prevention. “Histopathology B. dermatitidis.” Online image. http://www.cdc.gov/fungal/blastomycosis/. Accessed on Nov 21, 2012.

6 MedicaLook. “Blastomycosis.” Online image. http://www.medicalook.com/Skin_diseases/Blastomycosis.html. Accessed on Nov 21, 2012.