Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 4-1994. A 38-year-old man with AIDS and the recent onset of diarrhea, hematochezia, fever, and pulmonary infiltrates

Clinical Practice Guidelines for the Management of Patients with Histoplasmosis: 2007 Update by the Infectious Diseases Society of America

Evidence-based guidelines for the management of patients with histoplasmosis were prepared by an Expert Panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 30:688–95). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. Since 2000, several new antifungal agents have become available, and clinical trials and case series have increased our understanding of the management of histoplasmosis. Advances in immunosuppressive treatment for inflammatory disorders have created new questions about the approach to prevention and treatment of histoplasmosis. New information, based on publications from the period 1999–2006, are incorporated into this guideline document. In addition, the panel added recommendations for management of histoplasmosis in children for those aspects that differ from aspects in adults.

Diagnosis and Management of Central Nervous System Histoplasmosis

Two cases of Histoplasma meningitis are presented, illustrating the difficulty in diagnosis and treatment. The first case occurred in a patient with acquired immunodeficiency syndrome as a relapse of disseminated histoplasmosis and resolved after prolonged treatment and ongoing antiretroviral therapy. The second case occurred in a cardiac allograft recipient as meningitis and focal brain lesions that responded to liposomal amphotericin B, but the patient died shortly after therapy was completed. Unfortunately, there are no prospective studies addressing the diagnosis and management of patients with histoplasmosis of the central nervous system from which to provide evidence-based guidelines for care. In the absence of such data, an approach will be presented on the basis of our experience and opinions.

Ileal perforation secondary to histoplasmosis in AIDS

Our patient presented with abdominal pain, weight loss, and fever with evidence of oral thrush and pelvic inflammatory disease on exam. Radiographs demonstrated a small bowel obstruction with free air. An exploratory laparotomy demonstrated 2 perforations of the distal ileum. Pathologic exam revealed features consistent with histoplasmosis. We discuss gastrointestinal involvement of histoplasmosis in AIDS and its treatment.

Hyponatraemia in AIDS

Hyponatraemia is very common in AIDS patients. It is observed in about 40-50% of hospitalized patients. It may contribute to overall mortality in advanced disease. Vasopressin measurements in these patients basically present two distinct syndromes: hyponatraemia and 'normal' vasopressin levels (i.e. measurable vasopressin) and hyponatraemia with suppressed vasopressin. Hyponatraemia with suppressed vasopressin is very rare and has only been observed in AIDS patients with dementia and primary polydipsia. Hyponatraemia and measurable vasopressin can be also divided into two syndromes. In some patients vasopressin is 'appropriately' elevated, i.e. in those with body fluid losses (diarrhoea) or chronic hypovolaemia (adrenal failure); these patients also present with hyperuricaemia and other signs of low blood volume. In other patients vasopressin is 'inappropriately' elevated in those with no clinical evidence of hypovolaemia (typically characterized by low serum uric acid levels) such as in Pneumocystis carinii pneumonia and other opportunistic infections leading to SIADH. CSWS is a relatively frequent complication in some patients with cerebral infection or tumour. High-dose trimethoprim (for Pneumocystis carinii prevention) acts as an amiloride-like drug and induces a clinical state characterized by hyponatraemia and hyperkalaemia which is indistinguishable from hyporeninaemic hypoaldosteronism. The mechanism of the hyponatraemia caused by other drugs (miconazole, pentamidine, amphotericin, vidarabine) is not as yet known.