South American Blastomycosis Clinical Presentation

After the inhalation of conidia, the fungus transforms into yeastlike cells inside the alveolar macrophages. This transformation induces a nonspecific inflammatory response, which generally limits the disease at this point. Most patients have no signs or symptoms.

• Adult chronic

  • After a latency period of weeks to decades, some adults have a chronic progressive form of the disease. The skin, mucous membranes, lungs, and lymph nodes primarily are affected.
  • Constitutional symptoms include low-grade fever, malaise, and weight loss.
  • Mucous membrane symptoms include pain at ulceration sites. Oral lesions may lead to pain with eating or drinking. Laryngeal and pharyngeal lesions can cause dysphagia, hoarseness, or stridor.
  • Respiratory symptoms include cough; mucous production, which may be blood-tinged; and dyspnea. Symptoms due to involvement of other organ systems are sometimes seen, such as abdominal pain from gastrointestinal involvement or headache from central nervous system involvement.
• Juvenile subacute

  • After a brief latency period, some children have a subacute severe disseminated form of the disease. In children, the major target of South American blastomycosis is the reticuloendothelial system.
  • Symptoms include fever, asthenia, anorexia, malaise, weight loss, and diarrhea.
  • Mucous membrane and respiratory symptoms are unusual.
  • Most other symptoms are related to lymph node enlargement, suppuration, and sinus tract formation.

• Adult chronic

  • Mucous membranes^[10] : Approximately one half of patients with chronic disseminated disease seek medical attention because of mucocutaneous lesions. Oral, nasal, pharyngeal, and laryngeal lesions begin as papules or plaques, which ulcerate. The lesions typically have granulomatous, mulberrylike surfaces and most commonly occur on the lips, gingiva, palate, buccal mucosa, and tongue. Lesions progress over months and are painful. Gingival lesions cause the loss of teeth, which makes eating difficult. Lesions slowly enlarge and coalesce, increasing the difficulties. Conjunctivitis and ulcerative lesions of the perianal area occasionally occur. See the image below. Ulcerated nodule on the tongue in a man with South American blastomycosis. Courtesy of Heidi Logemann, Professor of Mycology, Universidad de San Carlos, Guatemala.
  • Skin: Skin lesions, which occur most commonly on the face, are polymorphous. They may be papular, nodular, ulcerated, papillomatous, or even tuberous. They most often arise from the direct extension of mucous membrane lesions. Occasionally, hematogenous spread results in widely scattered lesions and subcutaneous abscesses. Lymph node breakdown can lead to cutaneous fistulae. Without treatment, lesions gradually enlarge. See the image below. Crusted plaques over the central part of the face in a man with South American blastomycosis. Courtesy of Rolando Vasquez, MD, Professor of Dermatology, Guatemala.
  • Lymph nodes: Extensive lymphadenopathy develops. Numerous visceral and subcutaneous nodes may be involved through hematogenous and lymphatic spread. Cervical nodes are commonly affected. Nodes are hypertrophic, firm, and painful. They sometimes suppurate, forming sinus tracts or ulcers in the skin.
  • Respiratory: Lung involvement occurs in 70-80% of patients. In 25% of patients with the chronic adult type of disease, the lungs are the only organ system involved. The clinical picture often resembles that of tuberculosis. Chronic dyspnea, cough, and sputum production develop.
  • Other: Hepatosplenomegaly, caused by hepatic and splenic lesions, occurs in approximately 5% of cases. Central nervous system involvement, both meningitis and parenchymal granulomatous disease, is observed in 5-25% of patients and causes mental status changes and seizures.^[11] Occasionally, adrenal insufficiency due to the destruction of the adrenal glands is observed. Intestinal ulcerations and osteomyelitis are other infrequent manifestations.
• Juvenile subacute

  • Mucous membranes: Mucosal involvement is rare, but mucosal ulcerations occasionally occur.
  • Skin: Subacute disease may be associated with an acneiform eruption or subcutaneous abscesses. Sometimes, scrofuloderma is produced as a result of suppuration of the underlying lymph nodes.
  • Lymph nodes: Lymphadenopathy is prominent. Nodes may enlarge to such a point that infection with P brasiliensis may be confused with leukemia or lymphoma. Lymph nodes often suppurate and form sinus tracts to the skin. Mesenteric adenopathy may lead to bowel obstruction.
  • Respiratory: Pneumonia sometimes occurs.
  • Other: Cachexia, hepatosplenomegaly, adrenal insufficiency, osteomyelitis, and gastrointestinal problems may also occur.

• The disease is caused by the inhalation of the fungus P braziliensis. Animal-to-human and human-to-human transmissions do not appear to occur. Direct inoculation of the skin or mucosal surfaces is rare.
• Rural workers, particularly woodcutters, are more frequently affected because of their increased contact with the soil.
• Alcohol and possibly tobacco smoking is associated with disseminated disease.
• South American blastomycosis has been identified as an AIDS-associated opportunistic infection. Patients with AIDS usually have a form of the disease that closely resembles the juvenile subacute type.^[12]
• Otherwise healthy patients who develop disseminated disease appear unable to mount a sufficient cellular immune response to the organism.