A 13-year-old boy suffering from celiac disease (CD) developed shortness of breath at exercise and episodes of malaise, fever and acute dyspnea following contact with pigeons. Lung function testing and chest X-ray suggested interstitial lung disease. Serum precipitins and a combined systemic and pulmonary reaction 4 h after challenge with an extract of pigeon droppings confirmed bird-fancier’s lung. This case exhibits two points of interest. Extrinsic allergic alveolitis was found in childhood in combination with CD and it may be considered that both these diseases are based on one common immunologic disorder; HLA-typing of the boy’s family showed that he carried HLA-DR 3 in a double dose and was therefore homozygous for HLA-DR 3. This is of some interest because extrinsic allergic alveolitis and CD are both associated with HLA-D