Differential Diagnosis for Fever with Chills at Night

Single Most Likely Diagnosis

• Malaria: This is often characterized by periodic fevers, typically occurring at night, accompanied by chills. The cyclical nature of the fever, corresponding to the life cycle of the parasite, is a hallmark of this disease.

Other Likely Diagnoses

• Tuberculosis (TB): Night sweats and fever are common symptoms of TB, especially in its pulmonary form. The fever can be persistent and is often accompanied by weight loss and cough.
• Pneumonia: Bacterial pneumonia can cause high fevers, chills, and sweating, which may worsen at night. The presence of a cough, sputum production, and shortness of breath can help differentiate it from other causes.
• Urinary Tract Infections (UTIs): While UTIs can present with a variety of symptoms, severe cases, especially pyelonephritis, can cause high fevers and chills, which may be more pronounced at night.

Do Not Miss Diagnoses

• Sepsis: Although sepsis can present with a wide range of symptoms, fever and chills are common. It's crucial to consider sepsis in any patient with fever, especially if there are signs of organ dysfunction or a clear source of infection.
• Endocarditis: Infective endocarditis can cause persistent fever, and while it may not have a specific nocturnal pattern, it's a diagnosis that must be considered, especially in patients with valvular heart disease or intravenous drug use.
• Meningitis: While meningitis typically presents with headache, stiff neck, and fever, the fever can sometimes be accompanied by chills. Given the potential for rapid progression and severe outcomes, meningitis must always be considered in the differential diagnosis of fever.

Rare Diagnoses

• Lymphoma: Certain types of lymphoma can cause periodic fevers, known as Pel-Ebstein fevers in the case of Hodgkin lymphoma. These fevers can last for several days and then remit, only to recur.
• Brucellosis: This zoonotic infection can cause undulant fever, which may rise and fall over a 24-hour period but doesn't necessarily follow a strict nocturnal pattern. It's more common in individuals who work with animals or consume unpasteurized dairy products.
• Relapsing Fever: Caused by Borrelia species transmitted by ticks or lice, this condition is characterized by recurring episodes of fever, which can be accompanied by chills and headache. The fever episodes can last for several days, followed by afebrile periods.