1Extrinsic allergic alveolitis (hypersensitivity pneumonitis, EAA) Immunologically mediated inflammatory reaction in the alveoli and in the respiratory bronchiolescauses: organic dusts (<5µm) moulds foreign proteins some chemicals diisocyanates organic acid anhydridesoften heavy, repeated exposure, most often at the work placehkes03
2EAAPathology: 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.
3Examples of EAA Etiology Farmer's lung mouldy haySaw mill worker's lung mouldy wood dustBird fancier's lung proteins in bird droppingsMushroom worker´s lung spores, mouldsMalt worker´s lung mouldy maltHumidifier lung contaminated humidifier waterCheese washer's lung Penicillium caseiSuberosis cork dust mouldDiisocyanate lung polyurethane hardenersHard metal worker's lung hard metal dust, cobalt
4Allergic alveoltis in Finland 1981-2001 (Finnnish Register of Occupational Diseases)
5SRR (standardized risk ratio) of EAA in some occupations Occupation SRR nfarmers and cattle tenders 9.2 (8.4-10) 928other printing workers (2.2-13) 5bookbindery workers (1.7-5) 7printers ( ) 10wood workers ( ) 13typesetters ( ) 10Keskinen et al. Työperäiset hengtystieallergiat. Jauhoastmasta sementti-ihottumaan.Työterveyslaitos, Helsinki 1997
6EAA, symptoms flu-like illness cough high fever, chills dyspnea, chest tightnessmalaise, myalgia 4-8 hours after exposurechronic disease: dyspnea in strain, sputum production, fatigue, anorexia, weight loss
7EAA, clinical findingsStatus 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 micronoduleslung function restriction, diffusing capacity decreases, hypoxemia, obstruction, hyperreactivitylab. tests rise of sedimentation rate, leukocytosis, neutrophiliaBAL marked lymphocytosis, T helper / T supressor cells decreased
10Diagnostics of EAAMain criteria 1. Exposure to arganic dust (history, spesific IgG antibodies, work place measurements). 2. Typical symptoms 3. Chest X-ray findingsAdditional 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
12EAA, treatment Stopping of exposure Oral steroids Farmer's lung: after recovery back to work excluding/minimizing the exposuremotorized respiratory ventilator, training!after reorganization of the job descriptionfollow-up
13EAA, prognosisContinuing 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.
14EAA, prevention reduction of dust exposure work hygienic improvements adequate respirators always during exposure - before any symptoms!occupational health careinformationfollow-upfinding symptomatic workers in time, to prevent permanent loss of pulmonary function
15Organic Dust Toxic Syndrome (ODTS) opening of silos pulmonary mycotoxicosisexposure to grain grain fever1986 diPico ODTSEtiology: heavy exposure to biological organic dusts mycotoxins and endotoxinsNo sensitizationNo latency timeprevalence numbers farmers 14% mushroom cultivation 37%
16ODTS Symptoms: Symptoms mild to severe, ceasing when no exposure fever, main symptomcoughirratative symptoms of mucous membranesfatiguemyalgiaSymptoms mild to severe, ceasing when no exposureSymptoms milder than in allergic alveolitisNo chronic form?
17ODTS, diagnostics Criteria not yet clear Investigated as allergic alveolitisExposure and timing of symptoms important, often a few hours after exposure.No findings in chest X-raylung function: normal or as in EAA but mildBAL: neutrophilia?Work place provocation test following symptoms, temperature, diffusion capacity and FEV1/PEF
18Differential Diagnostics: Extrinsic allergic alveolitis (EAA)/Asthma(OA)/ODTS Feature EAA OA ODTSSymptoms Cough, dyspnea Cough, dyspnea Flu-like symptoms fever feverOnset after exposure Gradual after 4-8h Immediate or Gradual after 3-8h latePhysical findings Bibasil. crackles Expirat. wheezes NoneChest X-ray Infiltrates/norm. Normal NormalLung function Restrictive Obstructive Normal?Peripheral eosinophilia No Yes? No
19ConclusionFarmer´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.
20LiteraturePickering 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: