A 22-year-old patient complains of a painful swelling in the right parotid gland. A week earlier the patient got a cheek abrasion which healed under the purulent crust. Over the past two days the patient had observed progressing pain and fever up to 38,6°C. Objectively: there is a soft tissue edema in the right parotid region, the skin is slightly strained but has not changed in colour. There is a dense painful infiltration 2,5x3,5 cm large, the skin over it exhibits limited mobility. The mouth can be fully opened, the mucous membrane around the orifice of the salivary duct is unchanged, the saliva is transparent. What is the most likely diagnosis?