Fibrosing alveolitis in an infant

A three month old female infant presented with unproductive cough, diffuse bilateral fine crackles, tachypnoea and failure to thrive despite a four month therapy with beta 2-agonists and antibiotics. A chest radiograph showing bilateral periphilar infiltrates and a patchy infiltrate in the right upper lobe and lingula did not explain the physical examination with diffuse bilateral fine crackles. As the condition did not improve and arterial oxygen tension (PaO2) and oxygen saturation decreased during the following two months, an open lung biopsy was performed. The surgeon described the lungs as rubbery in consistency and histological findings showed patchy mild interstitial fibrosis and thickened alveolar septa. A therapy with prednisone daily was started and given over a period of four months, but did not show sufficient improvement. Only after addition of azathioprine was clinical improvement and normalization of blood gases noted.