Differential Diagnosis for a 3.5-Year-Old with Nose Bleeding and Fever

Single Most Likely Diagnosis

• Viral Upper Respiratory Infection (URTI): The combination of nose bleeding (epistaxis) and fever in a child is often associated with viral upper respiratory infections. The dry air and increased nasal congestion can lead to nosebleeds. This condition is common in children and usually resolves on its own.

Other Likely Diagnoses

• Allergic Rhinitis: Allergies can cause nasal irritation, leading to bleeding, especially when combined with fever due to a secondary infection.
• Nasal Trauma: Accidental trauma to the nose, such as from a fall or picking, can cause bleeding and might be accompanied by a fever if there's a secondary infection.
• Sinusitis: Although less common in young children, sinusitis can cause nasal discharge, fever, and potentially nosebleeds due to the inflammation and infection of the sinuses.

Do Not Miss Diagnoses

• Leukemia: Although rare, leukemia can present with nosebleeds due to thrombocytopenia (low platelet count) and fever. It's crucial to consider this diagnosis to avoid missing a potentially life-threatening condition.
• Infectious Mononucleosis (Mono): Caused by the Epstein-Barr virus, mono can lead to fever and, in some cases, nosebleeds due to thrombocytopenia or splenic rupture, which is a medical emergency.
• Meningitis: While typically presenting with more severe symptoms like headache, stiff neck, and altered consciousness, in rare cases, especially in young children, the initial presentation might be atypical, including fever and possibly nosebleeds due to increased intracranial pressure.

Rare Diagnoses

• Osler-Weber-Rendu Syndrome (Hereditary Hemorrhagic Telangiectasia): A genetic disorder that leads to the formation of abnormal blood vessels, which can cause recurrent nosebleeds and might be associated with fever if there's an infection.
• Granulomatosis with Polyangiitis (formerly known as Wegener's Granulomatosis): A rare autoimmune disorder that can cause inflammation of the blood vessels, leading to symptoms including nosebleeds and fever.
• Vitamin K Deficiency: Although rare in children, a deficiency in vitamin K can lead to coagulopathy, resulting in easy bruising and bleeding, including nosebleeds, and might be accompanied by fever if there's an underlying infection.