Extrinsic allergic bronchiolo-alveolitis in children.

Fifteen children, 6-14 years old, who were heavily exposed to pigeon droppings, presented with cough, chills and breathlessnes on mild exertion. Twelve gave immediate positive skin test reactions to pigeon droppings. Ten of the fifteen also gave a late (Arthus) reaction, and seven gave a positive delayed reaction which was maximal at 24--72 hr. Nine children had precipitins against avian droppings. In ten patients who were tested for lymphocyte transformation, five gave positive responses to both serum and pigeon droppings. Radiological findings of the chest showed parenchymatous infiltrations and diffuse interstitial reticulations, suggestive of extrinsic allergic alveolitis. In a control group of fifteen heavily-exposed children who had no symptoms, immediate and late skin reactions occurred respectively in five and two. One only had a positive precipitin test, and one of five tested had a positive lymphoblastic transformation. In a non-exposed comparable group of children, all tests were negative except for one immediate positive skin response. Children heavily exposed to the inhalation of avian antigens can develop extrinsic allergic bronchiolo-alveolitis.