Differential Diagnosis
The patient's symptoms have progressed from fever and headache to include neck stiffness, photophobia, haematemesis, haematuria, pallor, and scleral icterus. This progression suggests a severe and potentially life-threatening condition. The differential diagnosis can be categorized as follows:
Single most likely diagnosis
- Malaria with complications: The initial symptoms of fever and headache, followed by worsening and the addition of haematemesis, haematuria, pallor, and scleral icterus, are consistent with severe malaria, particularly if the patient is in an area where malaria is endemic. The progression to include signs of anemia (pallor), jaundice (scleral icterus), and bleeding (haematemesis and haematuria) suggests a severe infection with potential multi-organ involvement.
Other Likely diagnoses
- Viral hemorrhagic fever (e.g., Dengue, Yellow Fever): These diseases can present with fever, headache, and progression to hemorrhagic symptoms and organ impairment, including liver dysfunction (indicated by scleral icterus) and severe thrombocytopenia leading to bleeding.
- Severe bacterial sepsis: Sepsis from bacterial infections can lead to a systemic inflammatory response syndrome (SIRS) with fever, headache, and progression to organ dysfunction, including coagulopathy (leading to haematemesis and haematuria), anemia, and jaundice.
- Leptospirosis: This bacterial infection can cause a wide range of symptoms, from mild to severe, including fever, headache, and in severe cases, hemorrhagic symptoms, jaundice, and renal failure.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningitis: Although the patient's symptoms have evolved, the initial presentation of fever, headache, and neck stiffness is highly suggestive of meningitis. The subsequent development of other symptoms does not rule out meningitis, especially if the patient has a severe or partially treated infection.
- Thrombotic thrombocytopenic purpura (TTP) or Hemolytic-uremic syndrome (HUS): These conditions can present with thrombocytopenia, microangiopathic hemolytic anemia, renal failure, and neurological symptoms, which could explain some of the patient's symptoms, including pallor, scleral icterus, and hemorrhagic manifestations.
Rare diagnoses
- Hantavirus infection: This viral infection can cause hemorrhagic fever with renal syndrome (HFRS) or hantavirus pulmonary syndrome (HPS), presenting with fever, headache, and in severe cases, hemorrhage and renal failure.
- Relapsing fever: Caused by Borrelia species, this condition can present with recurring episodes of fever, headache, and in some cases, hemorrhagic manifestations and jaundice, particularly if left untreated or if treatment is delayed.