From the photo, the swelling appears more localized around the back lower gum near the molar region rather than the typical pattern of Parotitis, which usually causes swelling near the cheek/jaw area close to the ear and often causes pain while eating or reduced saliva flow.
This looks more suggestive of:
* local gum inflammation
* irritation from partially erupted wisdom tooth/pericoronitis
* food impaction/infection around the molar
* traumatic biting of swollen gum tissue
The fact that:
* pain increases while chewing,
* opposing tooth is biting the swollen gum,
* swelling is localized inside the mouth,
makes a dental/gum cause more likely than viral parotitis from the image and symptoms provided.
Next Steps
1. Revisit a dentist if:
* swelling increases,
* pus/bad taste develops,
* fever occurs,
* mouth opening becomes painful,
* facial swelling appears,
* or pain worsens.
2. You may need:
* dental examination specifically for wisdom tooth eruption/pericoronitis
* X-ray (OPG) if wisdom tooth involvement is suspected
3. Meanwhile:
* warm salt water gargles 4–5 times/day
* maintain oral hygiene gently
* avoid chewing on that side
* avoid very spicy/hard foods
4. If viral parotitis is truly present, symptoms usually include:
* swelling near ear/cheek externally,
* pain while salivating/eating,
* fever/body ache,
* tenderness over salivary gland
Your current picture does not strongly point toward classic parotitis.
Health Tips
* Food trapped near the last molar commonly causes this type of gum swelling.
* Do not repeatedly touch or press the area with fingers/tongue.
* Chlorhexidine mouthwash (if prescribed by dentist) may help reduce local gum inflammation.
* Stay hydrated.
* If the swelling starts spreading to the face or causes difficulty swallowing/breathing, seek urgent care immediately.
A focused online dental consultation with review of the exact tooth position and symptoms can help determine whether this is simple gum inflammation, wisdom tooth-related infection, or something requiring antibiotics or a dental procedure.