PT  - JOURNAL ARTICLE
AU  - Grunes, Dianne
AU  - Beasley, Mary Beth
TI  - Hypersensitivity pneumonitis: a review and update of histologic findings
AID  - 10.1136/jclinpath-2012-201337
DP  - 2013 Oct 01
TA  - Journal of Clinical Pathology
PG  - 888--895
VI  - 66
IP  - 10
4099  - http://jcp.bmj.com/content/66/10/888.short
4100  - http://jcp.bmj.com/content/66/10/888.full
SO  - J Clin Pathol2013 Oct 01; 66
AB  - Hypersensitivity pneumonitis (HSP) is a poorly understood entity typically caused by exposure to an inciting antigen such as fungi, thermophilic bacteria or animal protein. Clinically, HSP is often divided into acute, subacute and chronic forms. While the subacute form is best described from a pathologic standpoint, the pathology of chronic HSP has only been critically evaluated in the past decade and the pathology of acute HSP is poorly described. The aim of this review is to summarise the current knowledge of pathogenetic theories of HSP and to review the current knowledge of the pathology of each stage of HSP and the main entities in the differential diagnosis.