Ehrlichia-induced hemophagocytic lymphohistiocytosis in two children

Area of Science:

• Pediatric Infectious Diseases
• Hematology
• Immunology

Background:

• Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome.
• Genetic factors are commonly associated with primary HLH, but secondary HLH can be triggered by infections or malignancies.

Observation:

• Two children presented with fever, rash, pancytopenia, elevated ferritin, coagulopathy, and hypertriglyceridemia.
• Clinical deterioration included respiratory distress and hypotension, necessitating intensive care unit (ICU) admission.
• Bone marrow biopsies confirmed hemophagocytosis, and Ehrlichia testing was positive.

Findings:

• Patients received doxycycline for Ehrlichiosis and were treated for HLH.
• Genetic testing for MUNC and perforin mutations was negative in both cases.
• Both children achieved a full clinical recovery.

Implications:

• Ehrlichiosis should be considered a potential trigger for HLH in pediatric patients.
• This highlights the importance of infectious disease workup in HLH diagnosis, especially in the absence of genetic predisposition.
• Early recognition and treatment of Ehrlichiosis can lead to favorable outcomes in HLH.