A 34-year-old man complains of pain in the area of his right eye, headache, and body temperature rise up to 38,6°C. Two days ago the patient developed an infiltration in the lower eyelid of the right eye. Objectively the eyelids are markedly swollen, palpebral fissure is closed, conjunctiva is swollen. Exophthalmos is observed. The eyeball is immobile, vision is impaired. Make the diagnosis: