Hello, most common cause for swelling of salivary gland is infection. Sialadenitis is an infection of the salivary glands. It is usually caused by a virus or bacteria. The parotid (in front of the ear) and submandibular (under the chin) glands are most commonly affected. Sialadenitis may be associated with pain, tenderness, redness, and gradual, localized swelling of the affected area. With medicines it takes atleast one week for symptoms to subside. Don't worry Please continue your medication.