September 2, 2014 Grand Rounds

Case # 1 A 47 year old immunocompetent man with no significant past medical history who presented with  6 weeks of headache, neck pain, and fever secondary to Cryptococcus neoformans infection

1. In immunocompetent patients, Cryptococcus neoformans usually affects the central nervous system causing subacute to chronic meningitis. Patients often present with headache that is repeatedly misdiagnosed as migraine or cluster headache. 

2. Apart from HIV infection and receipt of immunocompromising medications (for transplantation, cancer, or rheumatologic disorders), other well-characterized immunodeficiency states that predispose to cryptococcal infection include CD4 lymphopenia and presence of anti-GM-CSF autoantibodies (read here).

3. Further ID pearls about cryptococcal infection are listed under Case # 1 June 24, 2014.

Case # 2. A 7-day old baby girl who presented with increased sleepiness, poor feeding, thrombocytopenia, and a diffuse macular rash secondary to parvovirus B19 infection

1. Parvovirus B19 causes fifth disease (erythema infectiosum). Another well-characterized but rarer and hence, less recognized illness that is associated with a rash secondary to parvovirus B19 is called papular-purpuric gloves and socks syndrome (PPGSS). PPGSS (see picture) is characterized by symmetrical and well-demarcated erythematous lesions on the hands and feet that end abruptly at the level of the wrist and ankle. It can present with high fever, mucosal lesions, and arthralgia (read here).

2. Other well-known illnesses associated with parvovirus B19 include: symmetric arthritis/arthralgia, transient aplastic crisis, chronic pure red cell aplasia, and non-immune hydrops fetalis. Rare manifestations include: acute hepatitis, fulminant liver failure, immune-complex glomerulonephritis, myocarditis, ITP, and TTP.

Case # 3. A 30 year old woman who is 13 weeks pregnant and who has a h/o splenectomy secondary to hereditary spherocytosis presented with fever and acute-onset watery diarrhea 2 days after eating in a restaurant secondary to Campylobacter jejuni infection (blood and stool culture positive)

1. Campylobacter usually causes a self-limited gastroenteritis and hence, treatment is not usually advised. However, treatment is recommended for those who present with severe disease (i.e. bloody diarrhea, high fever, extraintestinal infection, worsening or relapsing symptoms, or symptoms > 1 week duration) or those at risk for severe disease (e.g. immunocompromised, elderly, and pregnant patients).

2. The prevalence of fluoroquinolone-resistant Campylobacter is rising. In Thailand and Spain, for example, the prevalence is as high as 80%. In the US, fluoroquinolone-resistant Campylobacter has also risen from 0% to 19% between 1989 and 2001. Hence, some authorities advocate a macrolide (azithromycin or erythromycin) as first line agent against this infection.

3. Other antibiotics that can be used against Campylobacter include: aminoglycosides, carbapenem (especially for severely ill patients), clindamycin, tetracyclines, and chloramphenicol. It is inherently resistant to trimethoprim and some beta-lactam antibiotics including penicillin and most cephalosporins.

4. Campylobacter fetus is an uncommon species of Campylobacter that usually affects immunocompromised hosts, including elderly and pregnant women, and causes bacteremia and meningitis.

5. More ID pearls about Campylobacter are listed under Case # 2 July 2, 2014.