18th February 2024

A 45-year-old female presents to the respiratory clinic with a 6-month history of worsening shortness of breath

A 45-year-old female presents to the respiratory clinic with a 6-month history of worsening shortness of breath, dry cough and intermittent fevers. She states that this comes on after spending time caring for her carrier pigeons and lasts approximately 24-48 hours after she goes to the coop. These symptoms did not come on while she worked in her office. However, she has started to feel short of breath, even while away. She denies any associated weight loss.

Examination reveals widespread inspiratory crackles. Spirometry showed reduced FEV1 and FVC with a normal FEV1/FVC ratio. HRCT showed scattered ground-glass opacities with air trapping and centrilobular nodules. IgE levels were normal.

Given the likely diagnosis, which hypersensitivity reaction is the underlying pathogenesis for this condition?

Select the SINGLE most appropriate option from the list below. Select ONE option only.