July 29, 2014 Grand Rounds

Case # 1. A 19 year old man with diffuse macular rash, bilateral red eyes, fever, headache, abdominal pain, diarrhea, elevated liver enzymes and leukocytosis secondary to acute leptospirosis

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1. Remember that not all patients with leptospirosis present with the deadliest form of the infection called Weil's syndrome (i.e. profound jaundice with total bilirubin out of proportion to the liver enzyme elevation, renal failure, pulmonary hemorrhage, hemorrhagic diathesis). Majority of patients present with the anicteric form of the disease.

2. There are usually two phases of anicteric leptospirosis (although, an overlap between the two commonly occurs):

     A. Septicemic phase.  Characterized by abrupt onset of fever, headache, chills, myalgia, conjunctival suffusion, nausea, vomiting, diarrhea, and rash. Lasts for 5-7 days.

• Conjunctival suffusion. Manifests as bilateral conjunctivitis without eye discharge (eyes appear "wet"). Although not specific for leptospirosis, its presence in a patient with nonspecific symptoms should raise suspicion for leptospirosis. In fact, the World Health Organization (WHO) includes this in its scoring system for diagnosing leptospirosis (read here).
• Myalgia is also a predominant symptom. Calf tenderness is most often cited in the literature and is also included in the WHO scoring system.
• Rash occurs in 8-12% of patients. It is usually transient. Can appear as urticarial, macular, maculopapular, or purpuric.

     B. Immune phase. Characterized  by aseptic meningitis in 80% of patients. Uveitis, renal insufficiency, respiratory symptoms, and hepatosplenomegaly may occur.

3. The icteric form of leptospirosis (Weil's syndrome) is not usually biphasic. It usually manifests with persistent fever and abrupt onset of jaundice and profound renal failure.

4. The diagnosis rests on serologic testing. The CDC defines a positive serology as a titer of >/= 1:200 by the microscopic agglutination test (MAT). At Barnes-Jewish Hospital, the samples are sent to the Mayo Clinic which uses indirect hemagglutination assay (IHA) for diagnosing leptospirosis. For this test, the cut-off of a positive result is a titer of at least 1:50. A single titer of >/= 1:100 is suggestive of active or recent leptospirosis. The IHA is 100% sensitive and 97% specific for leptospirosis compared with the MAT.

Case # 2. A 3 year old girl coming from a trip to Cameroon, presents with fever, abdominal pain, vomiting, and diarrhea secondary to non-typhoidal Salmonella infection

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1. Non-typhoidal Salmonella is the most common cause of bacteremia in Africa according to one study.

2. Non-typhoidal Salmonella infection is usually self-limited. Treatment is required for patients with severe symptoms (e.g high fever, prolonged diarrhea needing hospitalization), for immunocompromised patients (e.g. AIDS, organ transplant, use of steroids or other immunosuppressive agents, sickle cell or other hemoglobinopathies), patients > 50 years, and those with prosthesis or severe valvular heart disease.

Case # 3. A 24 year old man who presented with a 1 month history of diffuse erythrodermic scaly rash, fever, weight loss, night sweats, arthralgia, leukocytosis, and diffuse lymphadenopathy mistaken for an infectious process and Still's disease; an excision biopsy of an enlarged inguinal lymph node revealed classic Hodgkin lymphoma

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1. In a patient with symptoms consistent with lymphoma and unrevealing infectious disease work-up, always pursue excisional lymph node biopsy. Fine needle aspiration biopsy is inferior to excisional biopsy for diagnosing lymphoma. Lymphoma is a great mimic! There are many cases reported in the literature of occult lymphoma diagnosed only with several excisional lymph node biopsies.