Viral Upper Respiratory Infection (URTI): The combination of upper respiratory symptoms and nose bleed (epistaxis) in a child is most commonly associated with viral infections, which can cause nasal mucosa dryness and irritation, leading to bleeding.

Allergic Rhinitis: Allergies can cause chronic nasal congestion, sneezing, and irritation, which may lead to epistaxis.
Nasal Dryness: Low humidity, especially in heated homes during winter, can dry out the nasal mucosa, making it more susceptible to bleeding.
Nasal Trauma: Digital trauma (nose picking) is a common cause of epistaxis in children.

Bleeding Disorders (e.g., Hemophilia, Von Willebrand Disease): Although rare, these conditions can present with recurrent or severe epistaxis and must be considered to avoid missing a potentially life-threatening condition.
Hypertension: Uncontrolled high blood pressure can cause epistaxis, and while rare in children, it's crucial to rule out secondary causes of hypertension.
Nasopharyngeal Tumors: Though uncommon, tumors in the nasal cavity or nasopharynx can cause recurrent nosebleeds and must be considered in the differential diagnosis.

Osler-Weber-Rendu Syndrome (Hereditary Hemorrhagic Telangiectasia): A genetic disorder characterized by the formation of abnormal blood vessels, which can lead to recurrent epistaxis.
Granulomatosis with Polyangiitis (formerly known as Wegener's Granulomatosis): A rare autoimmune disorder that can cause inflammation of the blood vessels, including those in the nose, leading to epistaxis.
Leukemia: In rare cases, leukemia can present with epistaxis due to thrombocytopenia or platelet dysfunction.