[Starling-induced hypersensitivity pneumonitis: minimal but persistent antigen exposure]

A 51-year old woman developed hypersensitivity pneumonitis (HP) after inhaling the excrement of starlings that populated a park adjacent to her home. The clinical symptoms consisted of a non-productive cough and grade II dyspnea and radiological interstitial micronodular involvement. The respiratory function tests showed a restrictive pattern with desaturation on effort and a biopsy using videothorascopy was highly suggestive of HP. After taking a very detailed clinical history the patient mentioned an increase in cough when she crossed a park near her home, where a high population of starlings lived in its trees. Specific antigen extracts were prepared and skin tests were performed, precipitins measured, and bronchial provocation tests specific to this antigen were all positive. This observation identified a species of bird capable of causing the disease and shows a lung disease secondary to the exposure of a not very large but persistent antigen load.