Plastic bronchitis (PB) is an uncommon disease characterized by the formation of bronchial casts that partially or completely block the bronchial lumen.1,2 It has been described as a complication of respiratory diseases, lymphatic abnormalities, infections and, particularly, congenital heart disease surgery, especially Fontan palliation,1,2 and is commonly confused with bronchoaspiration.2 We report a case of idiopathic PB.

A 10-year-old boy was admitted for irritative cough, pain in left hemithorax and dyspnea with onset 3 weeks previously. Of note on examination was severe hypoventilation of the left hemothorax. Anteroposterior chest X-ray showed left pulmonary collapse (Fig. 1A). Pneumonia was suspected, so intravenous antibiotics were started, with no clinical or radiological improvement. Lung computed tomography showed atelectasis of the left upper and lower lobes due to bronchial stenosis located 2cm from the carina. The patient's mother was consulted again and she remembered a choking fit when the boy was eating a hamburger approximately 2 months previously. In view of suspected foreign body, fiberoptic bronchoscopy (FB) was performed revealing a foreign body in the left main bronchus. Multiple fragments (Fig. 1B and C) were extracted by rigid bronchoscopy (RB). Two weeks later, the patient's situation worsened. FB was repeated, showing fragments of yellowish intrabronchial foreign bodies that were extracted by RB, and on pathological examination were reported to be mucoid, fibrinopurulent material. In view of this, PB was diagnosed and treatment with nebulized DNase was started. After 2 relapses of atelectasis, oral prednisolone (2mg/kg/day), azithromycin (500mg/day, 3 days/week) and nebulized N-acetylcysteine were added. Various complementary studies were performed to rule out diseases associated with PB; all were negative. Two years later, the patient remains asymptomatic and continues to receive azithromycin.

Fig. 1.

(A) Massive left pulmonary atelectasis. (B) Bronchial cast of up to 4cm in length extracted by rigid bronchoscopy. (C) Other bronchial casts.

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PB is a rare, heterogeneous lung disease.1 Documented cases are generally secondary to an underlying condition.1 The most widely accepted classification is that of Seear, based on the characteristics of the bronchial cast and the underlying disease2: Type I (inflammatory) consists of fibrin casts, Charcot-Leyden crystals and eosinophilia, and is generally associated with allergies or inflammatory diseases2; Type II consists of mucin casts and occurs with congenital heart disease.2 Clinical manifestations are non-specific and vary widely, including expulsion of bronchial casts, dyspnea, wheezing, fever and cough, similar to an asthma attack or aspiration of foreign body,1,2 as was the case in our patient. Radiological signs are non-specific, including mainly atelectasis of the involved segment and compensatory hyperinflation.2 A more specific radiological finding is an elongated opacity with undulating borders.2 Treatment is a source of controversy, and recommendations are generally based on isolated cases or series of heterogeneous cases.2 The most common treatments are azithromycin,3 nebulized N-acetylcysteine, urokinase or recombinant tissue plasminogen activator (rt-PA) and DNase, respiratory physiotherapy and corticosteroids for PB associated with asthma or infections,4 and in more severe cases, extraction of the casts by bronchoscopy.1,2 Prognosis tends to be good,1 except in cases with associated congenital heart disease, where mortality rates can reach 29% and life-threatening events can occur in up to 41% of patients.5 Despite its rarity, it is worth underlining the need for considering this disease in the differential diagnosis of intrabronchial foreign body, particularly in cases of recurrent atelectasis.