Hypersensitivity pneumonitis (HP), also called extrinsic allergic alveolitis, is a respiratory syndrome involving the lung parenchyma and specifically the alveoli, terminal bronchioli, and alveolar interstitium, due to a delayed allergic reaction. Such reaction is secondary to a repeated and prolonged inhalation of different types of organic dusts or other substances to which the patient is sensitized and hyper responsive, primarily consisting of organic dusts of animal or vegetable origin, more rarely from chemicals. The prevalence of HP is difficult to evaluate because of uncertainties in detection and misdiagnosis and lacking of widely accepted diagnostic criteria, and varies considerably depending on disease definition, diagnostic methods, exposure modalities, geographical conditions, agricultural and industrial practices, and host risk factors. HP can be caused by multiple agents that are present in work places and in the home, such as microbes, animal and plant proteins, organic and inorganic chemicals. The number of environment, settings and causative agents is increasing over time. From the clinical point of view HP can be divided in acute/subacute and chronic, depending on the intensity and frequency of exposure to causative antigens. The mainstay in managing HP is the avoidance of the causative antigen, though the complete removal is not always possible due to the difficulties to identify the agent or because its avoidance may lead to major changes in life style or occupational settings. HP is a complex syndrome that needs urgently for more stringent and selective diagnostic criteria and validation, including wider panels of IgG, and a closer collaboration with occupational physicians, as part of a multidisciplinary expertise.
Gruchow HW, Hoffmann RG, Marx JJ Jr, Emanuel DA, Rimm AA. Precipitating antibodies to farmer’s lung antigens in a Wisconsin farming population. Am Rev Respir Dis. 1981;124(4):411–5. PubMed
Ohshimo S, Bonella F, Guzman J, Costabel U. Hypersensitivity pneumonitis. Immunol Allergy Clin N Am. 2012;32:537–56. CrossRef
Thomeer MJ, Costabel U, Rizzato G, Poletti V, Demedts M. Comparison of registries of interstitial lung diseases in three European countries. Eur Respir J Suppl. 2001;32:114s–8s. PubMed
Katzenstein AL. Surgical pathology of the non-neoplastic lung disease. 4th ed. Philadelphia: Saunders Elsevier; 2006. p. 151–8.
Meyer KC, Raghu G, Baughman RP, on behalf of the American Thoracic Society Committee on BAL in interstitial lung disease, et al. An official American Thoracic Society clinical practice guideline: the clinical utility of bronchoalveolar lavage cellular analysis in interstitial lung disease. Am J Respir Crit Care Med. 2012;185(9):1004–14. CrossRefPubMed
Barrios RJ. Hypersensitivity pneumonitis: histopathology. Arch Pathol Lab Med. 2008;132:199–203. PubMed
- Hypersensitivity pneumonitis: a complex lung disease
Gian Galeazzo Riario Sforza
- BioMed Central
Neu im Fachgebiet HNO
Mail Icon II