A Case of Hemophagocytic Lymphohistiocytosis Associated With Mediterranean Spotted Fever in a Healthy 29-Year-Old Female

A 29-year-old female presented with fever, headache, and epigastric pain. Though her initial presentation was benign and nonspecific, she soon developed a full-blown cytokine storm with disseminated intravascular coagulation. She was diagnosed with hemophagocytosis secondary to Rickettsia conorii infection. A good outcome was achieved thanks to prompt diagnosis and proper treatment.

Japanese Spotted Fever with Hemophagocytic Lymphohistiocytosis

Japanese spotted fever (JSF) is an uncommon but potentially fatal infection transmitted by tick bites. We herein report a fulminant case of JSF infection that occurred in an immunocompetent adult that was complicated by disseminated intravascular coagulation and hemophagocytic lymphohistiocytosis (HLH). We discuss the difficulty in making the diagnosis and identifying the complication of HLH in our patient. HLH is a rare complication of rickettsiosis, and this is the first reported case in English of JSF complicated by HLH in an immunocompetent adult. Secondary HLH caused by rickettsiosis requires a different treatment from primary HLH. Rickettsiosis must therefore be considered in patients with HLH.

Update on tick-borne rickettsioses around the world: a geographic approach

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These zoonoses are among the oldest known vector-borne diseases. However, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. Several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections, and novel Rickettsia species of undetermined pathogenicity continue to be detected in or isolated from ticks around the world. This remarkable expansion of information has been driven largely by the use of molecular techniques that have facilitated the identification of novel and previously recognized rickettsiae in ticks. New approaches, such as swabbing of eschars to obtain material to be tested by PCR, have emerged in recent years and have played a role in describing emerging tick-borne rickettsioses. Here, we present the current knowledge on tick-borne rickettsiae and rickettsioses using a geographic approach toward the epidemiology of these diseases.

Q fever and Mediterranean spotted fever associated with hemophagocytic syndrome: case study and literature review

BACKGROUND

Hemophagocytosis during Q fever (QF) and Mediterranean spotted fever (MSF) is rare and only a few cases have been reported. We aimed to investigate the characteristics, outcome, and treatment of QF/MSF-associated hemophagocytosis.

METHODS

We retrospectively reviewed all patients with a diagnosis of QF or MSF and suspected hemophagocytic syndrome (HS), according to Henter's criteria, between 2002 and 2011, and compared the latter to patients without HS or with lymphoma-associated HS.

RESULTS

Seventeen patients with HS (median age 42 years, range 5-68 years; five females (29%)) with QF (n=8) and MSF (n=9) were included in this study. When comparing patients with QF- and MSF-associated HS with patients without HS (n=11), HS-associated signs (splenomegaly, ferritinemia, hypertriglyceridemia, and cytopenia) were significantly more frequent in patients with histological HS (p<0.05), along with a greater number of Henter's criteria. Despite the presence of HS-associated signs, treatment was similar in these two subgroups, including the time to recovery and the outcome. When compared to lymphoma-associated HS (n=10), the outcome in QF/MSF-associated HS was significantly different, with mortality in 70% of lymphoma patients versus none in QF- and MSF-associated HS (p<0.05).

CONCLUSION

Hemophagocytosis is a rare occurrence during the course of QF and MSF. The presence of profound cytopenia is quite unusual in QF and MSF and should bring to mind the presence of associated HS. Nevertheless, hemophagocytic syndrome is associated with a good outcome in this condition.

Haemophagocytic syndrome and rickettsial diseases

Haemophagocytic lymphohistiocytosis is a rare but potentially fatal disease resulting from dysregulated activation and proliferation of lymphocytes. We present a case of haemophagocytic syndrome occurring in a 5-year-old Italian boy as a complication of Mediterranean spotted fever. The characteristics of this case have been analysed and contextualized among those of another 15 cases of haemophagocytic syndrome associated with rickettsial diseases found through a systematic review of the international literature.