Presentation is loading. Please wait.

Presentation is loading. Please wait.

Extrinsic allergic alveolitis (hypersensitivity pneumonitis, EAA)

Similar presentations

Presentation on theme: "Extrinsic allergic alveolitis (hypersensitivity pneumonitis, EAA)"— Presentation transcript:

1 Extrinsic allergic alveolitis (hypersensitivity pneumonitis, EAA)
Immunologically mediated inflammatory reaction in the alveoli and in the respiratory bronchioles causes: organic dusts (<5µm) moulds foreign proteins some chemicals diisocyanates organic acid anhydrides often heavy, repeated exposure, most often at the work place hkes03

2 EAA Pathology: Granulomatotic inflammation around the alveoli and the peripheral bronchioles. Exudate with plasma cells and lymphocytes. Macrophages, epitheloid cells and giant cells in the granulomas in the middle of the inflammation process. After the exposure ceases the reaction disappeares in 3-4 months. If the exposure continues, the exudation organises into fibrine and an irreversible pulmonary fibrosis follows.

3 Examples of EAA Etiology
Farmer's lung mouldy hay Saw mill worker's lung mouldy wood dust Bird fancier's lung proteins in bird droppings Mushroom worker´s lung spores, moulds Malt worker´s lung mouldy malt Humidifier lung contaminated humidifier water Cheese washer's lung Penicillium casei Suberosis cork dust mould Diisocyanate lung polyurethane hardeners Hard metal worker's lung hard metal dust, cobalt

4 Allergic alveoltis in Finland 1981-2001 (Finnnish Register of Occupational Diseases)

5 SRR (standardized risk ratio) of EAA in some occupations
Occupation SRR n farmers and cattle tenders 9.2 (8.4-10) 928 other printing workers (2.2-13) 5 bookbindery workers (1.7-5) 7 printers ( ) 10 wood workers ( ) 13 typesetters ( ) 10 Keskinen et al. Työperäiset hengtystieallergiat. Jauhoastmasta sementti-ihottumaan.Työterveyslaitos, Helsinki 1997

6 EAA, symptoms flu-like illness cough high fever, chills
dyspnea, chest tightness malaise, myalgia 4-8 hours after exposure chronic disease: dyspnea in strain, sputum production, fatigue, anorexia, weight loss

7 EAA, clinical findings Status dyspnea, cyanosis, crepitant rales digital glubbing (chronic form) Chest X-ray normal or small nodules/diffuse infiltrates/ ground glass appearance chronic form: pulmonary fibrosis HRCT normal or ground glass appearance centrilobular micronodules lung function restriction, diffusing capacity decreases, hypoxemia, obstruction, hyperreactivity lab. tests rise of sedimentation rate, leukocytosis, neutrophilia BAL marked lymphocytosis, T helper / T supressor cells decreased

8 EAA: HRCT, acute disease

9 EAA: HRCT, chronic disease

10 Diagnostics of EAA Main criteria 1. Exposure to arganic dust (history, spesific IgG antibodies, work place measurements). 2. Typical symptoms 3. Chest X-ray findings Additional criteria 1. Decreased diffusion capacity 3. Hypoxia during rest or decreasing during excercise 4. Restriction in spirometric values 5. Lung biopsy with findings of allergic alveolitis 6. Provocation test (at work place) positive All main criteria and two of the additional ones are needed for diagnosis (Terho, Keuhkosairaudet, Duodecim 20

11 EAA, differential diagnostics
Organic Dust Toxic Syndrome (ODTS) Sarcoidosis Drug-induced pneumonitis Viral and mycoplasma pneumonias Tuberculosis Allergic bronchopulmonary aspergillosis Collagen-vascular diseases Lymphangitis carcinomatosa Pulmonary fibrosis (DIP) Pneumoconioses

12 EAA, treatment Stopping of exposure Oral steroids
Farmer's lung: after recovery back to work excluding/minimizing the exposure motorized respiratory ventilator, training! after reorganization of the job description follow-up

13 EAA, prognosis Continuing exposure, relapsing disease leads to pulmonary fibrosis, permanent loss of pulmonary function and cor pulmonale. When Finnish cases with farmer's lung were followed for 10 years, 23% had findings of pulmonary emphysema or pulmonary fibrosis.

14 EAA, prevention reduction of dust exposure work hygienic improvements
adequate respirators always during exposure - before any symptoms! occupational health care information follow-up finding symptomatic workers in time, to prevent permanent loss of pulmonary function

15 Organic Dust Toxic Syndrome (ODTS)
opening of silos pulmonary mycotoxicosis exposure to grain grain fever 1986 diPico ODTS Etiology: heavy exposure to biological organic dusts mycotoxins and endotoxins No sensitization No latency time prevalence numbers farmers 14% mushroom cultivation 37%

16 ODTS Symptoms: Symptoms mild to severe, ceasing when no exposure
fever, main symptom cough irratative symptoms of mucous membranes fatigue myalgia Symptoms mild to severe, ceasing when no exposure Symptoms milder than in allergic alveolitis No chronic form?

17 ODTS, diagnostics Criteria not yet clear
Investigated as allergic alveolitis Exposure and timing of symptoms important, often a few hours after exposure. No findings in chest X-ray lung function: normal or as in EAA but mild BAL: neutrophilia? Work place provocation test following symptoms, temperature, diffusion capacity and FEV1/PEF

18 Differential Diagnostics: Extrinsic allergic alveolitis (EAA)/Asthma(OA)/ODTS
Feature EAA OA ODTS Symptoms Cough, dyspnea Cough, dyspnea Flu-like symptoms fever fever Onset after exposure Gradual after 4-8h Immediate or Gradual after 3-8h late Physical findings Bibasil. crackles Expirat. wheezes None Chest X-ray Infiltrates/norm. Normal Normal Lung function Restrictive Obstructive Normal? Peripheral eosinophilia No Yes? No

19 Conclusion Farmer´s lung is the most usual extrinsic allergic alveolitis. Chronic form leads to severe disability. Reduction of the exposure to biological dust by work hygienic improvements and using adequate respirators is important. The humidifiers and other sources of exposure should be cleaned. Early recognition of the symptoms is essential. ODTS is a milder syndrome, symptoms can be prevented using respirator when exposed.

20 Literature Pickering CAC, Newman Taylor AJ. Extrinsic allergic bronchioloalveolitis (hypersensitivity pneumonia). In RW Parkes, Occupational Lung Disorders, Third edition1994, Butterworth Heineman Ltd, UK, Terho EO. Orgaanisten pölyjen aihettamat keuhkokudoksen yliherkkyysreaktiot. Kirjassa Allergologia, toim. Haahtela T, Hannuksela M, Terho E.O. Kustannusosakeyhtiö Duodecim, 1999: Terho EO. Allerginen alveoliitti ja sitä muistuttavat sairaudet. Kirjassa Keuhkosairaudet, toim. Kinnula V. Laitinen L.A.L, Tukiainen P. Kustannusosakeyhtiö Duodecim, 2000:

Download ppt "Extrinsic allergic alveolitis (hypersensitivity pneumonitis, EAA)"

Similar presentations

Ads by Google