Parapharyngeal abscesses are a rare complication (2, 3, 5) of acute inflammation of the lymphoid tissue of the throat, the tonsils, the parotid gland, the paranasal sinuses and of the middle ear. The boundaries of the parapharyngeal space are the lateral pharyngeal wall medially and anteriorly, the medial pterygoid muscle and the parotid gland laterally, and the prevertebral fascia posteriorly. It extends from the base of the skull to the hyoid bone and encompasses the internal carotid, the internal jugular, nerves IX, X, XII, and the cervical sympathetic trunk. Since the area is surrounded by muscle and fasciae from all sides, the inflammatory processes do not usually manifest outside. They can therefore cause life-threatening complications: mediastinitis and meningitis. The treatment of choice is an incision and intraoral or extraoral drainage of the parapharyngeal space and intensive target intravenous antibiotic therapy.

Diagnostic considerations and an evaluation of the results of conservative treatment of parapharyngeal abscesses in infants.

Three boys aged 7, 12 and 14 months were treated in the Clinic of Paediatric Otolaryngology in Warsaw between July 2007 and July 2008 for abscesses of the parapharyngeal space. Each child underwent an interview, a physical examination and additional tests, including mainly an ultrasound and a CT scan of the cervical area.

The initial diagnosis upon the patient´s arrival at the hospital included a retropharyngeal abscess (right in two cases, left in one). Before their admission to the hospital, all the patients had been treated for 4-6 days for throat infection and hyperthermia exceeding 38°C, and they had been administered oral fenspiridum and amoxicillin. The parents also reported lack of appetite or thirst. Physical examination revealed bilateral hypertrophy of the lymph nodes in all the patients. In 2 cases an inflammatory infiltration with a coexistent ipsilateral oedema on the neck reduced neck mobility, and also in 2 cases the ipsilateral tonsil protruded significantly. In one case minimal lockjaw, and in one contralateral eyelid ptosis was present. Horner Syndrome was not observed. In additional tests all patients presented with elevated inflammatory parameters: with symptoms of anaemia from iron deficiency, in tests Hb 8.8, 9.5, 10.4, Hct 29.1, 29.8, 27.9; erythrocytes 3.35, 3.9, 4.12. One of the patients underwent a transfusion of 150 mL of type-specific red cell concentrate. Tests for mononucleosis, toxoplasmosis and cytomegaly were carried out on all patients and they excluded infection. To confirm the diagnosis of parapharyngeal abscess, a CT scan of the neck and repeated ultrasound images were made in order to monitor the treatment. The CT demonstrated a fluid space in the parapharyngeal space of the average size of 12x34x19 mm, 12x12 mm and the density of 28 to 36 HU. The ultrasounds did not confirm the presence of fluid spaces in two cases, but they showed inflammatory infiltration and necrotic tissues. All the patients received clindamycin as empirical intravenous therapy (8); 2 patients were additionally given ceftriaxone (Biotraxon), and one child cefotaxime (Claforan). In one boy vancomycin had to be administered on the fifth day of treatment because of a fever exceeding 38°C. The patients were hospitalised for 10 to 14 days until their physical condition improved, the inflammatory parameters decreased and the fluid spaces in the ultrasound diminished. The subsequent outpatient treatment lasted 10 days and consisted of oral administration of antibiotics.

The treatment of choice of abscesses in the parapharyngeal space in adults is surgery with intravenous administration of antibiotics. All the children hospitalised in the Clinic were treated conservatively with combined antibiotic therapy with careful monitoring for a possible progression of the condition (2, 3). All the patients were completely cured and no complications (breathing dysfunction or progression of changes towards the mediastinum) were observed (8). The analysis of these cases raises the question of whether the described condition was indeed an abscess of the parapharyngeal space, or if it was simply an inflammatory infiltration and necrotic tissues of the area. In 2 cases the ultrasound did not confirm the presence of fluid spaces shown in the CT scan (6). The literature discusses some cases of surgery of diagnosed abscesses where, upon incision, no abscess cavities or purulent matter were found (5). All the patients in the present study presented with symptoms of anaemia in additional tests. It is necessary to consider whether it was the anaemia that predisposed the children to present with such a serious complication in the course of inflammation of the upper respiratory tract or if it was the abscess of the parapharyngeal space which led to all the infants becoming anaemic.

1. Abscess of the parapharyngeal space can be a complication of pharyngitis in children.

2. When no life-threatening symptoms (breathing dysfunction, mediastinitis) are present, conservative treatment with antibiotics may be administered.

3. If the general condition improves, body temperature returns to normal and the inflammatory parameters lower within 24-48 h, exclusively conservative treatment may be continued.

4. On the 6th-7th day of treatment a significant decrease in the fluid space of the abscess was observed in the ultrasound.

5. Ultrasound is more efficient at distinguishing an inflammatory infiltration and necrotic tissues from purulent matter than other imaging tests.

6. The patients were hospitalised until the inflammatory parameters returned to normal and the symptoms of the abscess in the ultrasound subsided. The subsequent antibiotic therapy lasted up to 3 weeks.

All the children with an abscess of the parapharyngeal space presented with anaemia.