[Girl with hypersensitivity pneumonitis. A case report].

Background: Hypersensitivity pneumonitis entails several inflammatory lung diseases that preferentially affect the alveolar and perialveolar tissue. It is a very rare disease in children, with a complicated diagnosis due to the fact that antigen exposure usually goes unnoticed.

Case report: A 12-year-old girl with dry cough, dyspnea, wheezing, and tachypnea, with partial improvement after treatment with inhaled bronchodilators and corticoids. The spirometry showed a restrictive pattern and reduced lung diffusion capacity; in the CT scan, centrilobular ground-glass opacities were observed, and a lymphocyte count of CD4/CD8 of 2.46 (lymphocytosis) was obtained from the bronchoalveolar lavage. IgG positivity to bird feathers was obtained.

Conclusions: The treatment of hypersensitivity pneumonitis is based on avoiding exposure to the causative agent, which is determined by the prognosis; for which taking an extensive medical history is of paramount importance. Corticosteroids can be prescribed based on the clinical response, the pulmonary function, and the radiological improvement.