A Brief discussion about the disease, its side effects and its cause.

1. Hypersensitivity Pneumonitis
PRESENTED BY:
SUKANYA HALDER
M.TECH, BIOTECHNOLOGY

2. Hypersensitivity
Pneumonitis
Extrinsic Allergic Alveolitis
A SYNDROME CHARACTERIZED BY DIFFUSE
INFLAMMATION OF LUNG PARENCHYMA
AND AIRWAYS IN RESPONSE TO INHALATION
OF ANTIGENS TO WHICH THE PATIENT HAS
BEEN PREVIOUSLY SENSITIZED

3. HP – Incidence and
Mortality
 General population based cohort study from a UK primary care
database: 271 cases from 1991-2003, approx. 0.9 per 100,000
person years. Mean age at diagnosis 57; male=female
 Increased risk of dying (hazard ratio 2.98)
 Less likely to smoke (OR 0.56)

4. HP Findings
 Ground glass opacities
 Poorly defined centrilobular nodules
 Mosaic attenuation on inspiration
 Air trapping on expiration
 Reticulation (fibrosis) when chronic

6. Classification of HP
 Acute HP
 Subacute or Intermittent HP
 Chronic progressive HP

7. Subacute or Intermittent HP
 Clinical-gradual cough, dyspnea, fatigue,
anorexia, wt. loss, malaise; tachypnea and
rales
 Lab-BAL lymphocytosis, hypoxemia. Restrictive
or mixed spiro, decreased DLCO
 CXR-nml, micronodular, reticular. HRCT
micronodules, ground glass, emphysema,
fibrosis
 Histopathology- noncaseating granulomas,
bronchiolitis with or w/o organizing pneumonia

8. Chronic Progressive HP
 Clinical-insidious cough, dyspnea,
fatigue, weight loss, clubbing
 Lab-not very helpful-BAL
lymphocytosis but not crisp;
restrictive, but usually mixed.
DL always reduced, and exertional
hypoxemia
 CXR-may be normal, but usually
progressive fibrosis; emphysema often
 Histopathology-granulomatous
pneumonia, BO with or w/o OP,
fibrosis

9. HP Diagnosis
 Known exposure to antigen-History,
environmental investigation, IgG antibodies
 Compatible clinical, radiographic,and physiology
 BAL lymphocytosis
 Positive inhalation challenge
 Histopathology

10. Clinical Prediction
 Exposure to known antigen
 Positive precipitating antibodies to that antigen
 Recurrent symptoms
 Inspiratory crackles
 Sx occurring 4-8 hours after exposure
 Weight loss
Lacasse Y, for the HP Study Group. Clinical Diagnosis of
Hypersensitivity Pneumonitis. Am J Respir Crit Care Med 2003; 168:
952-958.

11. Helpful Clues to Recognize
HP
 Hx recurring pneumonias, esp. if some
regularity
 Sx after moving to new house or job
 Pets, esp. birds, with patient or family
 Hx water damage to home or office
 Use of hot tub, sauna, or pool
 Others with similar sx or have left work for
illness
 Pt feels better when away from home or
office

12. HP Associated with
Farming
 Moldy hay, grain, silage-Farmer’s lung
 Mold on pressed sugar cane-Bagassosis
 Tobacco plants
 Mushroom workers
 Potato riddlers
 Cheese washers

13. HP Associated with
Ventilation and Water-
Related Contamination
 Humidifier fever
 Unventilated shower
 Hot tub lung
 Sauna taker’s lung
 Lifeguard lung

14. HP Associated with
Birds/Poultry
 Bird fancier’s lung
 Poultry worker’s lung
 Turkey handling disease
 Canary fancier’s lung
 Duck fever

15. HP Associated with
Veterinary Work and
Animal Handling
 Laboratory worker’s lung
 Pituitary snuff taker’s disease
 Furrier’s lung
 Bat lung
 Coptic lung (mummy handlers)
 Pearl oyster shell pneumonitis

16. HP Associated with Grain
and Flour Processing
 Grain measurer’s lung
 Miller’s lung
 Malt worker’s disease

17. HP Associated with Milling
and Construction
 Wood dust pneumonitis
 Sequoisis
 Maple bark disease
 Wood trimmer’s disease
 Suberosis (moldy cork)
 Composter’s lung
 Thatched-roof lung

18. HP Associated with Plastics,
Painting, Electronics, Etc.
 Chemical HP – Toluene diisocyanate
 Detergent worker’s lung
 Pauli’s reagent alveolitis
 Vineyard sprayer’s lung
 Bible printer’s lung
 Epoxy resin lung

19. HP Treatment
 Antigen avoidance
 Corticosteroids – 0.5-1 mg/kg daily

20. HP Treatment
Hypersensitivity Pneumonitis may result in ILD.
Screening of ILD Patients may lead to finding traces of Hypersensitivity Pneumonitis.
Then we can treat those patients accordingly.

21. HP Prevention/Avoidance
 Reduction of antigen burden
 Design of facilities-moisture control
 Preventative maintenance, esp. HVAC
 Protective devices-filters, respirators