54 THE NOSE AND PARANASAL SINUSES considered to be prone to sinus infection. Examination of the nose shows mucopus either in the floor of the nasal cavity or in the middle meatus. The mucosa of the inferior concha may be congested and swollen. In children with an underlying allergy there is often a small swollen area in the floor of the nose opposite the anterior end of the inferior concha. Radiography should be carried out in all children suspected of sinus infection, and a lateral view to show the nasopharynx should always be Fig. 23. Acute ethmoiditis with orbital cellulitis in a child aged 6. requested. The films may be misleading. Many children are incapable of clearing their noses by blowing and the nasal secretions which remain in the nasal cavities combined with the swelling of the nasal mucous membrane result in a lack of air entry into the sinuses. This may give a false impression of sinus opacity on the radiograph, and it requires a paediatric radiologist to read the films accurately. The opacity from infection is much more dense, while a fluid level in a sinus is diagnostic of infection. Thickening of the mucous lining of the maxillary sinuses may be due to allergic oedema or to a chronic infection of the sinuses. A solitary polypoid swelling in the floor of the maxillary sinus may be due either to nasal allergy or to a cyst within the sinus. Diagnostic proof puncture is performed on these children who show radio- graphic evidence of sinus disease. This should be an aspiration proof puncture, and not an antral wash-out because the latter will expel not only the antral contents but also those of the nasal cavities into the receiver, and this may give a false impression of sinus infection. If mucopus is obtained on aspiration of the maxillary sinus, it can only have come from the sinus, and should besent forbacteriological culture and sensitivity tests. AHigginson's syringe may then be attached to the cannula and the sinus washed clear of infected contents. This is often curative, but if infection recurs a polythene tube may be threaded through the cannula and the sinus washed out through it, or the appropriate antibiotic instilled directly into the antrum.