SESSION TYPE: Infectious Disease Cases I
PRESENTED ON: Monday, October 22, 2012 at 01:45 PM - 03:00 PM
INTRODUCTION: Immunocompromised hosts are at increased risk of infection from endemic mycoses such as Histoplasma capsulatum, a fungus pervasive in the southeastern U.S. Physicians should be knowledgeable of unique presenting features of progressive disseminated histoplasmosis.
CASE PRESENTATION: 41 year old AA female with AIDS having a CD4 cell count of 6, noncompliance with HAART, and prior Pneumocystis jirovecii pneumonia presents to the emergency department after being found unresponsive. She reports three weeks of fatigue, weight loss, and fever. On examination she is noted to be febrile, tachycardic, and tachypneic with a spO2 of 94% on room air. She is somnolent and oriented only to person. Pulmonary auscultation reveals rales, and a diffuse papular rash is present on her trunk and upper extremities. Her labs show evidence of acute kidney injury, pancytopenia, and an elevated LDH of 6438 with a normal haptoglobin. An initial review of her peripheral smear shows no abnormalities. Her initial chest roentgenogram demonstrates mild peribronchial thickening without infiltrates. On hospital day #2 her peripheral smear reveals intracellular and extracellular yeast and Amphotericin B is initiated. Dermatology is consulted for a biopsy of the rash which demonstrates budding yeast forms consistent with histoplasmosis, confirmed by strongly positive urine quantitative histoplasma antigen. Despite all efforts, her clinical condition continues to deteriorate and she expires on hospital day #6.
DISCUSSION: This patient demonstrates some of the findings that may be encountered in an immunocompromised patient with progressive disseminated histoplasmosis (PDH). Fever and weight loss are the most commonly encountered symptoms seen in up to 75% of patients. 25% of individuals with PDH may not present with pulmonary symptoms, and when present usually only have mild interstitial infiltrates on chest roentgenogram. Physical examination is typically unrevealing except for hepatosplenomegaly; however, in rare cases a papular rash containing abundant yeast may be present. On laboratory evaluation pancytopenia is present in approximately a quarter of patients. Additionally, case series have shown that infection with histoplasma can produce an LDH greater than 600. The diagnosis of PDH can frequently be made first by a review of a peripheral smear which displays intracellular yeast within phagocytes.
CONCLUSIONS: Classic findings of fever and weight loss combined with an elevated LDH and characteristic rash point to the diagnosis of PDH in this patient. A review of a peripheral smear and skin biopsy showing yeast combined with a positive urine histoplasma antigen confirm the diagnosis.
1) Sarosi GA, Davies SF: Endemic mycosis complicating human immunodeficiency virus infection. West j Med 1996;164:335-340
2) Butt, A. Serum LDH level as a clue to the diagnosis of histoplasmosis. AIDS Read. 2002 Jul;12(7):317-21.
DISCLOSURE: The following authors have nothing to disclose: Jennifer Trevor, Michael Brown, Victor John Thannickal
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