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 (cerebral malaria and severe anemia): The initial symptoms of fever and headache, followed by the administration of malaria medication, suggest that malaria was a primary concern. The worsening of symptoms, including the development of neck stiffness and photophobia, could indicate cerebral involvement. The presence of haematemesis and haematuria, along with pallor and scleral icterus, points towards severe anemia and possibly hemolysis, which are complications of malaria, especially if the treatment was ineffective or if the disease has progressed.
Other Likely diagnoses
- Viral hemorrhagic fever (e.g., Lassa fever, Ebola): These diseases can present with fever, headache, and progression to hemorrhagic symptoms like haematemesis and haematuria. The presence of neck stiffness and photophobia could be indicative of meningitis, which can be a complication of some viral hemorrhagic fevers.
- Meningitis (bacterial or viral): The symptoms of neck stiffness and photophobia are classic for meningitis. However, the presence of haematemesis, haematuria, and the initial response to malaria medication complicate this diagnosis.
- Sepsis with disseminated intravascular coagulation (DIC): Sepsis can cause a wide range of symptoms, including fever, headache, and hemorrhagic manifestations if it progresses to DIC. The pallor and scleral icterus could be signs of anemia and liver dysfunction, respectively.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Thrombotic thrombocytopenic purpura (TTP) or hemolytic uremic syndrome (HUS): These conditions can present with hemolytic anemia, thrombocytopenia, and renal failure, which could explain some of the patient's symptoms. They are less common but critical to diagnose due to their high mortality if untreated.
- Leptospirosis: This infection can cause a wide range of symptoms, including fever, headache, and in severe cases, hemorrhagic manifestations and liver or kidney failure. It's essential to consider in patients with exposure history.
Rare diagnoses
- Hemorrhagic fever with renal syndrome (HFRS): Caused by hantaviruses, this disease can present with fever, headache, and hemorrhagic symptoms, followed by renal failure.
- Relapsing fever (tick-borne or louse-borne): While primarily known for recurring episodes of fever, relapsing fever can also cause hemorrhagic manifestations and other systemic symptoms in severe cases.
Each of these diagnoses requires careful consideration of the patient's history, physical examination, and laboratory findings to determine the most appropriate course of action. The justification for each diagnosis is based on the combination of symptoms presented and the potential for these conditions to cause severe, life-threatening complications if not promptly and properly treated.