Geotrichosis

Definition

Geotrichosis is a rare infection by either of two fungi, Geotrichum candidum or Blastoschizomyces capitatus. Infection by G. candidum is described here.

Synonyms

Oidiomycosis. (B. capitatus is also known as G. capitatum or Trichosporon capitatum). Fr: Geotrichose. Ger: Geotrichose. Sp: Geotrichosis.

Geographic Distribution

Geotrichum candidum occurs worldwide, but is not a common cause of clinical disease.

Epidemiology and Pathology

Geotrichum candidum is an opportunistic fungus most often found in immunodeficient patients. It has been recognized in citrus fruits, milk products, and sewage. It is a filamentous mold which reproduces by segmentation of the hyphae into arthrospores: these may give rise to a yeast-like bud. It is found endogenously in the normal mucosa of the alimentary tract. In those who are immunosuppressed it may become an opportunistic pathogen.

Histopathologically there are multiple microabscesses with a surrounding inflammatory reaction containing the fungi. Recognition of the fungus establishes the diagnosis.

Clinical Characteristics

Most clinical infections are in patients with malignant disease, of either sex and aged 23-79 years. The majority seem to have been acquired following catheterization. Clinically the infection usually appears in the mouth but the lungs or gut can be infected. In the mouth there are white patches, similar to "thrush." When in the lungs, patients present with fever, asthma, or cough, with sputum which is sometimes blood stained and is often very gelatinous. The pulmonary form resembles tuberculosis or chronic Klebsiella (Friedlander's) pneumonia.

Gastrointestinal infection causes abdominal pain, diarrhea, blood, and mucus in the stools. The clinical diagnosis is often "colitis." Geotrichosis has caused arthritis following trauma, and resulted in fever and tender swelling of the joints.

Imaging Diagnosis

Only the pulmonary infection has any significant imaging findings. In many patients the chest radiograph will be normal, but some may show peribronchial thickening and a fine nodular mottling at the bases of the lungs. In others there will be air space consolidation, usually in the upper lobes. This may progress to cavitation, usually with thin walls, and the overall pattern resembles tuberculosis. None of these imaging changes is diagnostic.