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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.