1

Introduction

Described in a few patients, plastic bronchitis is a rare disorder of unknown etio-pathogenesis. This disease is characterized by formations of fibrinous mucous plugs that acquire the three-dimensional architecture of the bronchial tree. Such lesions can obstruct totally the airways causing severe respiratory distress. This illness has been reported in patients affected by chronic lung diseases such as asthma, cystic fibrosis (CF), recurrent pulmonary infections and bronchopulmonary aspergillosis and it can be associated with systemic diseases such as sickle cell anemia and congenital cardiopathy, especially in patients after Fontan surgery .

Initial symptoms may mimic the framework of foreign body inhalation with obstructive pulmonary symptoms resistant to therapy . The patients may manifest acute respiratory distress, fever, wheezing, cough, dyspnoea, and accessory muscle use. The symptoms are progressive and resistant to therapy so much so that a bronchoscopic examination becomes necessary. Endoscopic procedure shows mucofibrinous material that completely occludes the airways. The treatment includes the removal of the mucous casts associated with bronchial lavages by means of bronchoscopy. A few past cases demonstrated the efficacy of medical treatment based on corticosteroids, antibiotics, mucolytic agents, and aerosol use alone .

Herein, a pediatric patient affected by plastic bronchitis who was treated successfully by inhalation therapy is described.

2

Case reports

A 5-year-old girl came to our attention for severe asthma symptoms lasting 3 months and not responding to proper asthma therapy (i.e., inhalation with salbutamol, ipratropium bromide and flunisolide and oral steroids plus oral antibiotic treatment with amoxicillin clavulanate, followed by clarithromycin and, then, cefpodoxime). Due to the persistence of a dry chronic cough and wheezing, a chest X-ray was performed. Radiologic examination showed a pattern of accentuated thickening of the bronchial tree in the lower lobes, without any signs of inhaled foreign bodies. At first visit, the child had normal height-weight growth, 96% oxygen saturation in room air, a mildly impaired heart rate (127 bpm), and slight polypnea. Her chest breath was harsh with rales and spread wheezing. The presence of persistent whooping-type cough prevented spirometry. After the initial assessment and an otorhinolaryngological evaluation, a diagnostic bronchoscopy and chest physiotherapy were planned. Patient underwent preoperatively inhalation treatment using dornase alpha 2,5 mg/day (Pulmozyme®, recombinant phosphorylated and glycosylated human deoxyribonuclease 1 protein) and hypertonic saline solution containing hyaluronic acid (Hyaneb®).

After 2 days, the child was hospitalized for respiratory distress, cyanosis, asthenia, and excessive coughing followed by difficult expectoration of three mucous “casts” 3–4 cm in length ( Fig. 1 ). Subsequently, the child undertook respiratory physiotherapy using a new device for lung expansion [the Easy Positive Airway Pressure (EzPAP)], which effectively produces a positive airway pressure throughout the breathing cycle. Her general conditions improved. The patient was no longer dyspnoeic with clearly less wheezing, with 98% oxygen saturation in room air. The sweat test performed in the suspicion of cystic fibrosis (CF) and echocardiogram were normal, whereas Haemophilus influenzae grew from bronchial secretions culture. The cytological and histological examination on sputum casts showed the presence of mucoid material mixed with histiocytes and granulocytic neutrophils in the total absence of other cell components. Since her health condition and O ₂ saturation value in ambient air were good, the scheduled bronchoscopy was not carried out. The patient carried on aerosol treatment associated with respiratory physiotherapy.

A bronchial expectorated cast.

The child’s good condition continued and she could cough up thick mucus without difficulty. Moreover, there was further improvement in her oxygen saturation and cough symptoms diminished and, then, totally disappeared. The patient was discharged after 5 days Diagnosis of plastic bronchitis was done and it was given aerosol therapy with 7% hypertonic saline supplemented with hyaluronic acid twice daily performing after salbutamol inhalation, and oral azitromycin. Furthermore, chest physiotherapy with the use of a positive expiratory pressure mask was added for the next three months.

During follow-up (1 year), her health conditions improved greatly. Mucus production was absent and there were intermittent episodes of bronchospasm. Hyaneb ^® treatment was suspended after 3 months after which there was a recurrence of a cough with yellowish sputum, which required a new treatment course with the drugs. The symptoms resolved promptly. At the last outpatient visit, a spirometry was performed. It showed normal respiratory function and resolution of the respiratory symptoms were observed.