| disease | Parapharyngeal Abscess |
Parapharyngeal abscess is a suppurative inflammation of the parapharyngeal space, which begins as cellulitis and progresses to abscess formation in its early stages. There are multiple routes of infection, such as acute inflammation in the palatine tonsils, pharyngeal tonsils, teeth, parotid glands, and lymph nodes associated with the nose and throat, all of which can spread to the parapharyngeal space. Particularly in children, these areas are common sites of infection, making the parapharyngeal space one of the most susceptible gaps in the head and neck to infection.
bubble_chart Etiology
1. Inflammation of adjacent tissues, such as acute pharyngitis, tonsillitis, acute rhinitis, and sinusitis, directly invades or spreads hematogenously to the parapharyngeal space, forming an abscess.
2. Direct rupture or extension of abscesses in adjacent tissues, such as peritonsillar abscess, retropharyngeal abscess, alveolar abscess, petrous bone abscess, and otogenic deep neck abscess (Bezold's abscess), may all lead to this condition.
3. Injury to the lateral pharyngeal wall by foreign objects or instruments, such as fish bone puncture or injury during endoscopy, can lead to infection, with inflammation spreading to the parapharyngeal space and forming an abscess. Surgeries involving the pharynx or oral cavity, such as tonsillectomy or tooth extraction, may introduce bacteria directly into the parapharyngeal space via the anesthetic needle, causing infection. Additionally, accidental penetration of the superior constrictor muscle during incision and drainage of a peritonsillar abscess may also result in this condition.
bubble_chart Clinical Manifestations
Swelling occurs in the submandibular region on the affected side, with localized hardness and significant tenderness. The patient tilts their head toward the affected side to alleviate pain. In severe cases, the swelling may extend upward to the parotid gland and downward along the sternocleidomastoid muscle to the supraclavicular fossa. If an abscess has formed, the area may become softer. Pharyngeal examination reveals bulging of the lateral pharyngeal wall, congestion and edema of the soft palate and palatal arches, and the tonsils being pushed toward the center of the pharyngeal cavity, while the tonsils themselves show no significant lesions. There is increased oral secretion, and due to restricted mouth opening, pharyngeal lesions may sometimes be unclear. If the infection is in the posterior space, it does not cause trismus, and the tonsils are not displaced.
The diagnosis can be confirmed based on clinical manifestations and relevant examinations, such as needle aspiration of pus from the neck swelling; B-ultrasound can detect fluid levels; X-ray imaging of the neck may reveal widening of the lateral pharyngeal soft tissue shadow; blood tests show a significant increase in total white blood cell count. However, because the abscess is located deep, fluctuation is difficult to detect during external neck palpation, so the presence or absence of fluctuation cannot be used as a basis for diagnosing a parapharyngeal abscess. This condition needs to be differentiated from retropharyngeal abscess and peritonsillar abscess.
1. Infection initial stage [first stage] Anti-inflammatory treatment is the main approach. To prevent the spread of inflammation and complications, sufficient antibiotics and sulfonamides should be administered. Apply local hot compresses or physiotherapy. The patient should rest in bed, drink plenty of water, and eat soft foods. Sedatives and laxatives may be given if necessary.
2. Abscess formation stage Incision and expelling pus via the external cervical approach is required. Under local anesthesia, make a longitudinal incision centered on the mandibular angle along the anterior border of the sternocleidomastoid muscle. Use vascular forceps to bluntly separate the soft tissue and enter the abscess cavity. After expelling pus, rinse thoroughly, place a drainage strip, partially suture the wound, and bandage it. Change the dressing daily, preferably rinsing the abscess cavity with antibiotic solution.
Due to the spread of inflammation, infections in surrounding tissues such as the retropharyngeal space and parotid space may occur. Carotid sheath infection is the most common and severe complication of parapharyngeal space infection. If the inflammation invades the carotid wall, it can lead to fatal massive hemorrhage. Involvement of the internal jugular vein may cause thrombophlebitis and septicemia, which are life-threatening.
