Brief Answer:
Might be suffering from Parotitis

Detailed Answer:
Hi,thank you for posting your query on health care magic.

Looking at the symptoms,your son might be suffering from Parotitis(Inflammation of the Parotid Gland).Parotid gland is a salivary gland which secretes saliva in the mouth through a duct.Blockage of this tube may lead to inflammation of the parotid gland.

He may get relief by taking following medicines:
Antibiotic like Augmentin,
Analgesic and Anti-inflammatory like Ibuprofen with Antacid like Rantac,
Antipyretic like Paracetamol in case of fever and
Vitamin C lozenges.

Also apply warm compresses over the swelling to reduce pain.Drink lots of fluids.
Gentle massage of the swelling from posterior to anterior may also help(if the swelling is a parotid gland swelling as the massage will help to drain the collected salivary secretions ).

If there is no improvement in a day or two after following the above measures,then it would be advisable to consult an Otolaryngologist Doctor

Hope this answers your question.I would be happy to answer if you have any follow-up questions.Take care.

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Brief Answer:
Seems less possibility of Infectious mononucleosis or mumps

Detailed Answer:
Hi,thank you for your follow-up question.

There seems less possibility of Infectious mononucleosis or Mumps.

Infectious mononucleosis generally present with sore throat and significant fatigue(weakness), palatal petechiae(small red or purple spots caused by bleeding visible in the palate) and Neck lymph node enlargement.

Mumps generally presents with bilateral parotid gland inflammation.

Even,if the cause is mumps or infectious mononucleosis,except antibiotics,the other treatment would remain the same as advised before.

Hope this answers your question.Take care.

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