Blastomycosis Clinical Presentation

Updated: Jan 09, 2019
  • Author: Chidinma Chima-Melton, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Presentation

History

Patients with blastomycosis may present with any of several patterns of illness, but 30-50% of persons infected may remain asymptomatic. Indeed due to this variability in its clinical presentation, blastomycosis has been dubbed "the great pretender" and a high index of suspicion is required to make an accurate diagnosis. [37]

The initial presentation may be a nonspecific flulike illness with fever, chills, myalgia, headache, chest pain, and a nonproductive cough, which resolves within days. Because of the brief and self-limited nature of these symptoms, blastomycosis may go undiagnosed except in the setting of a known outbreak. Alternatively, patients may present with an acute illness resembling bacterial pneumonia, with high fever, chills, a productive cough, and pleuritic chest pain; the sputum is mucopurulent or purulent.

A chronic pneumonia may occur and simulate tuberculosis or lung cancer, with low-grade fever, a productive cough, night sweats, chest pain, and weight loss. The sputum is mucopurulent or purulent, and hemoptysis may be present. Often, these patients receive multiple courses of antibiotics before the diagnosis of blastomycosis is made. Chronic blastomycosis pneumonia is progressive without antifungal therapy.

Other patients, often older persons or those with immune compromise states (such as patients with human immunodeficiency virus infection / acquired immunodeficiency syndrome [HIV/AIDS] or solid organ transplant recipients) may present with an acute, rapidly progressive, severe disease. These cases manifest as acute respiratory distress syndrome (ARDS), with fever, shortness of breath, tachypnea, hypoxemia, and diffuse pulmonary infiltrates. The mortality rate for ARDS-associated blastomycosis is high, ranging from 33% to 67%. [40, 41]

Extrapulmonary features may include the following:

  • Skin lesions - The skin is the second-most common site of spread after the lungs. Commonly seen skin manifestations are purplish-gray verrucous lesions with heaped borders or friable lesions that ulcerate. Microabscesses and subcutaneous nodules can also be seen.

  • Bone lytic lesions - Seen in 25% of cases with extrapulmonary manifestations, [14] these lesions may present with bone or joint pain, and soft-tissue swelling may be present. Osteomyelitis can involve any bone, although the lower spine and pelvis are most commonly affected. Contiguous spread of bone disease can result in deep abscesses or arthritis.

  • Genitourinary - Prostatitis, orchitis, or epididymitis can be seen in men, [12] and rare cases of endometritis and tubo-ovarian abscess have been reported in women.

  • Central nervous system (CNS) involvement - In 5-10% of cases, meningitis and intracranial or epidural abscesses may be seen. Cases of central diabetes insipidus have been reported from CNS blastomycosis.

Unusual sites of disseminated infection include the larynx (manifesting as hoarseness), uterus, reticuloendothelial system (liver, spleen, lymph nodes, bone marrow), oropharynx, nose, and thyroid.

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Physical Examination

The physical examination in patients with blastomycosis may not reveal any abnormal findings. In the pneumonic form, there may be findings associated with pneumonic consolidation (eg, dullness on percussion, bronchial breath sounds, egophony, rales). Decreased or absent breath sounds suggest pleural effusion.

Skin lesions are more common on the face, neck, and extremities, and they often represent the strongest indication of the diagnosis of blastomycosis. Early in the disease course, the lesions are sharply demarcated papules or pustules, or they present as subcutaneous nodules. Multiple lesions may appear simultaneously or in sequence.

Within a few weeks to months, the primary lesions evolve into ulcers, with indurated dusky or violaceous granulomatous or verrucous borders, or into vegetating plaques (see the image below). Typically, the border is arciform or serpiginous, contains numerous tiny pustules or microabscesses covered with crust, and rises abruptly from the normal surrounding skin.

Cutaneous blastomycosis. Cutaneous blastomycosis.

Over a period of months to years, the lesions enlarge, eventually involving a substantial portion of the face, for example, and produce severe disfigurement. As the lesions enlarge, they heal centrally, with an atrophic scar studded with telangiectasia.

Although the vast majority of patients with cutaneous blastomycosis acquire it by dissemination from a pulmonary focus, [42] a few well-documented cases of primary cutaneous (inoculation) blastomycosis have been described in laboratory workers. The skin lesions are described as "chancriform" and are accompanied by nodular lymphangitis.

Rarely, bone involvement leads to a draining abscess. The affected joint may be tender and swollen.

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