July 8, 2014 Grand Rounds

Case # 1. A 24 year old man from Arkansas with no significant past medical history who presented with 9 days of fever, nausea, vomiting, diarrhea, abdominal pain, cholecystitis, and elevated liver enzymes secondary to acute histoplasmosis

Taken from http://wwwnc.cdc.gov/eid/article/17/9/10-1987-f1

1. Gastrointestinal (GI) histoplasmosis as a presenting symptoms of acute histoplasmosis is rare but is actually found in 70% of disseminated histoplasmosis on autopsy. It should be considered in the differential diagnosis of a patient with acute progressive gastroenteritis. The geographic distribution of histoplasmosis cases in the US is shown in the diagram.

2. Most common presentation of GI histoplasmosis include mucosal ulcers and abdominal lymphadenopathy. It can also present as ileitis that mimic inflammatory bowel disease (can add this in the differential diagnoses of infectious etiologies that cause ileitis such as tuberculosis, amoebiasis, Yersinia/Salmonella infection, and actinomycosis among others).

3. A negative Histoplasma antigen test does not rule out disseminated histoplasmosis. The urine Histoplasma antigen test is more informative in the immunocompromised host compared to the immunocompetent patient (read here).

4. Histoplasma antibody testing is more informative in immunocompetent hosts compared to immunocompromised patients where it can be falsely negative.

Case 2. A 2 week old preterm and small for gestational age infant with persistent methicillin-susceptible Staphylococcus aureus bacteremia

1. An aggressive search for any focus of infection is a priority in patients with persistent staphylococcal bacteremia. Have a low threshold for draining localized areas of fluid collections.

Case 3. A 59 year old woman with alcoholic cirrhosis, CMV colitis, recurrent profuse diarrhea,  respiratory failure, and pancytopenia who was found to have Pneumocycstis jirovecii pneumonia (PCP)

Taken from http://bestpractice.bmj.com/best-practice/images/bp/en-gb/19-4_default.jpg

1. Cirrhosis and severe malnutrition are enough to make one immunocompromised. Infection with opportunistic infections secondary to CMV and PCP have been reported in cirrhotic and malnourished patients. Include PCP in the differential diagnoses of refractory pneumonia even in non-AIDS and non-translant patients.

2. The presence of cystic lung disease and pneumatoceles, although not specific for any etiologic agent for pneumonia, is an  underrecognized radiolographic manifestation of PCP.