160 THE LARYNX, BRONCHI AND OESOPHAGUS terminal bronchi and the child, even with a tracheostomy, may not be able to effect an efficient gas exchange in the lungs. Thus while antibiotics, such as ampicillin, inhalations and adrenaline sprays, may cure many cases, a considerable proportion will require intra- venous hydrocortisone. Of these some will require further help, and the procedure of choice in these cases is to intubate the child and carry out intermittent positive-pressure ventilation. If the endotracheal tube requires to be in place for more than 72 hours a tracheostomy should be performed and intermittent positive-pressure ventilation continued for as long as is necessary by this route. In the severe case, a close watch should be kept for the possibility of the development of a Gram-negative septicaemia, which may well cause renal shut-down. ACUTE ALLERGIC LARYNGITIS This may be a manifestation of a systemic allergic problem such as a drug reaction, a local allergic reaction such as angioneurotic oedema or a contact mucositis as a result of inhaling the offending allergen in the form of dust particles. On examination, the first two aetiological factors cause the larynx to be swollen and pale, but the contact mucositis (due to a product such as bauxite) presents as a red, swollen painful larynx not unlike that seen in acute laryngitis, but without the accompanying respiratory infection and fever. Initial treatment should be with intramuscular chlorpheniramine maleate (Piriton) 4 mg and intravenous hydrocortisone 100 mg if necessary. Because there should be a quick response to this once the precipitating allergen is removed, further respiratory obstruction should be handled by intubation rather than tracheostomy. The less severe contact mucositis is more difficult to get rid of and occasion- ally persists for months in rather a painful way. Sprays such as 5 per cent glucose in glycerine may be used together with analgesics.