Differential Diagnosis for Fever with Rash and Hepatosplenomegaly
Single Most Likely Diagnosis
- Infectious Mononucleosis (Mono): Caused by Epstein-Barr virus (EBV), it commonly presents with fever, rash (especially if the patient is taking ampicillin), and hepatosplenomegaly. The combination of these symptoms, particularly in a young adult, makes mono a leading consideration.
Other Likely Diagnoses
- Viral Hepatitis: Various forms of viral hepatitis (A, B, C, D, E) can cause fever, rash, and hepatosplenomegaly due to the liver inflammation and systemic symptoms associated with these infections.
- Systemic Lupus Erythematosus (SLE): An autoimmune disease that can present with a wide range of symptoms, including fever, rash, and hepatosplenomegaly, due to its systemic nature and potential to affect multiple organ systems.
- Endocarditis: Although more commonly associated with heart valve abnormalities, endocarditis can cause fever, rash (e.g., Janeway lesions), and hepatosplenomegaly, especially if there is significant embolic phenomenon or immune complex deposition.
Do Not Miss Diagnoses
- Meningococcemia: A severe infection caused by Neisseria meningitidis, which can rapidly progress and cause fever, rash (petechial or purpuric), and hepatosplenomegaly. It is critical to identify and treat promptly due to its high mortality rate.
- Rocky Mountain Spotted Fever (RMSF): A tick-borne illness caused by Rickettsia rickettsii, characterized by fever, rash, and potential hepatosplenomegaly. Early recognition and treatment are crucial to prevent severe outcomes.
- Leptospirosis: A zoonotic infection that can cause a wide range of symptoms, including fever, rash, and hepatosplenomegaly, particularly in individuals exposed to contaminated water.
Rare Diagnoses
- Lymphoma: Certain types of lymphoma, such as Hodgkin lymphoma, can present with systemic symptoms like fever, rash, and hepatosplenomegaly due to lymphadenopathy and organ involvement.
- Brucellosis: A zoonotic infection that can cause fever, rash, and hepatosplenomegaly, particularly in individuals who work with animals or consume unpasteurized dairy products.
- Ehrlichiosis/Anaplasmosis: Tick-borne illnesses that can present with fever, rash, and hepatosplenomegaly, often requiring specific diagnostic tests for identification.