From the Guidelines
Hepatosplenomegaly can be caused by various infectious agents, including bacterial, viral, parasitic, and fungal infections, with the most significant causes being typhoid fever, brucellosis, tuberculosis, bacterial endocarditis, Epstein-Barr virus, cytomegalovirus, HIV, viral hepatitis, malaria, leishmaniasis, schistosomiasis, toxoplasmosis, histoplasmosis, and coccidioidomycosis 1.
Infectious Causes
The infectious causes of hepatosplenomegaly can be categorized into:
- Bacterial infections: typhoid fever (Salmonella typhi), brucellosis, tuberculosis, and bacterial endocarditis
- Viral infections: Epstein-Barr virus (infectious mononucleosis), cytomegalovirus, HIV, and viral hepatitis (particularly hepatitis A, B, and C)
- Parasitic infections: malaria, leishmaniasis, schistosomiasis, and toxoplasmosis
- Fungal infections: histoplasmosis and coccidioidomycosis
Diagnosis and Treatment
Diagnosis of hepatosplenomegaly typically requires a combination of clinical history, physical examination, laboratory tests, and imaging studies 1. Treatment is directed at the underlying infectious cause, often involving appropriate antimicrobial therapy, supportive care, and in some cases, management of complications such as portal hypertension or organ dysfunction. For example, systemic antifungal therapy is necessary for hepatosplenic aspergillosis, and either lipid amphotericin derivatives or itraconazole should be considered 1.
Key Considerations
It is essential to consider the patient's travel and exposure history, as well as their immune status, when evaluating the cause of hepatosplenomegaly. In endemic regions, parasitic infections such as malaria, leishmaniasis, and schistosomiasis should be considered as potential causes. In immunocompromised patients, fungal infections like histoplasmosis and coccidioidomycosis should be considered. The most recent and highest quality study 1 highlights the importance of considering schistosomiasis as a cause of hepatosplenomegaly, particularly in patients with a history of travel to endemic regions.
From the Research
Infectious Causes of Hepatosplenomegaly
The infectious causes of hepatosplenomegaly (enlargement of the liver and spleen) can be attributed to various pathogens. Some of the key infectious causes include:
- Malaria: Chronic exposure to malaria can lead to hepatosplenomegaly, even in the absence of other infections such as Schistosoma mansoni 2.
- Schistosomiasis: Infection with Schistosoma mansoni can cause hepatosplenomegaly, and the severity of the condition can be exacerbated by concurrent chronic exposure to malaria 3, 2.
- Fungal infections: Hepatosplenic fungal infection (HSF) is a distinct form of invasive fungal infection that mainly affects the liver, spleen, and occasionally the kidney. Candida species are the most common pathogens responsible for HSF 4.
- Infectious mononucleosis: This is another infectious cause of hepatosplenomegaly, although the exact mechanisms are not fully understood 5.
Geographic Distribution and Prevalence
The prevalence of hepatosplenomegaly due to infectious causes can vary depending on the geographic location. For example:
- In tropical regions, malaria and schistosomiasis are common causes of hepatosplenomegaly, with as many as 80% of people potentially affected 5.
- In sub-Saharan Africa, hepatosplenomegaly is highly prevalent among school-aged children, with chronic exposure to malaria and Schistosoma mansoni infection being major contributing factors 3, 2.