Reading Time:
Pathology
Hypersensitivity reaction to inhaled allergens
Acute phase: inflammation
Chronic exposure: granuloma formation, bronchiolitis obliterans
Aetiology
Multiple allergens: bird fanciers lung, pigeon fanciers lung, farmers lung (Micropolyspora Faeni), malt workers lung (Aspergillus clavatus)
Signs
Crackles, fever, weight loss if chronic process.
Symptoms
Acute (4-6hrs post-exposure): dry cough, dyspnoea, fever, rigors, myalgia.
Chronic: progressive dyspnoea, weight loss, cor pulmonale
Investigations
FBC: ↑WCC (neutrophils), ↑CRP/ESR
Chest X-Ray: bilateral mid-zone shadowing
Spirometry: restrictive defect, allergen testing
Treatment
Remove offending allergen, in the acute phase give oxygen if hypoxic and steroids
Prognosis
Resolves if allergen removed +/- steroids in the acute period
May progress to permanent lung damage if chronic exposure, type 1 respiratory failure, cor-pulmonale
Key Facts
Lorem ipsum dolor sit amet, sapien platea morbi dolor lacus nunc, nunc ullamcorper. Felis aliquet egestas vitae, nibh ante quis quis dolor sed mauris.
Key Images
Lorem ipsum dolor sit amet, sapien platea morbi dolor lacus nunc, nunc ullamcorper. Felis aliquet egestas vitae, nibh ante quis quis dolor sed mauris.
Key References
Lorem ipsum dolor sit amet, sapien platea morbi dolor lacus nunc, nunc ullamcorper. Felis aliquet egestas vitae, nibh ante quis quis dolor sed mauris.