Acute Pharyngitis or Tonsillitis: This is likely due to the sudden onset of fever, cold, and subsequent palatal weakness, which could be indicative of a viral or bacterial infection affecting the throat, leading to inflammation and weakness of the palate.

Viral Neuropathy: Certain viral infections can cause neuropathy affecting the cranial nerves, including those that control the palate, leading to weakness and regurgitation of liquids.
Infectious Mononucleosis: Caused by Epstein-Barr virus, it can lead to fever, sore throat, and sometimes neurological manifestations including weakness of the palate.
Sinusitis: Inflammation of the sinuses can lead to referred pain and potentially affect the nerves controlling the palate, though this is less direct.

Brainstem Encephalitis: Although rare, encephalitis affecting the brainstem can cause a range of neurological symptoms including cranial nerve palsies, which could manifest as palatal weakness.
Lemierre's Syndrome: A rare but serious condition following a throat infection, characterized by thrombophlebitis of the internal jugular vein and can lead to neurological complications.
Meningitis: Inflammation of the protective membranes covering the brain and spinal cord, which can present with fever, headache, and neurological deficits, including cranial nerve palsies.

Myasthenia Gravis: An autoimmune disease that can cause muscle weakness, including the muscles of the palate, though it's rare in children and typically presents with more widespread muscle weakness.
Diphtheria: A bacterial infection that can cause a membrane to form in the throat, leading to respiratory and neurological complications, including palatal weakness, though it's rare in areas with good vaccination coverage.
Botulism: A rare illness caused by a toxin that can lead to muscle weakness, including the muscles used for swallowing, though it's more commonly associated with difficulty in swallowing solids rather than liquids.