Pulmonary eosinophilia Definition Pulmonary eosinophilia is a group

Pulmonary eosinophilia

Definition Pulmonary eosinophilia is a group of diseases with eosinophil cells–mediated pulmonary tissue damage and characterized by the association of radiographic (usually pneumonic) abnormalities and peripheral blood eosinophilia.

Classification A/ Extrinsic (cause known) 1. Helminths: e. g. Ascaris, Toxocara, Filaria 2. Drugs: nitrofurantoin, sulfasalazine, imipramine, chlorpropamide. 3. Fungi: e. g. Aspergillus fumigatus causing allergic bronchopulmonary aspergillosis.

B/ Intrinsic (cause unknown) 1. Cryptogenic eosinophilic pneumonia 2. Eosinophilic granulomatosis with polyangiitis (formerly Churg–Strauss syndrome) 3. Hypereosinophilic syndrome 4. Polyarteritis nodosa

Acute eosinophilic pneumonia: a febrile illness of less than 5 days duration with diffuse alveolar damage causing pulmonary infiltrates & hypoxic respiratory failure. Diagnosis is confirmed by bronchoalveolar lavage with > 25% of infiltrate is eosinophil and the treatment is mainly with corticosteroids.

Chronic eosinophilic pneumonia: a insidious onset of fever, malaise, SOB & dry cough, more common in middleaged females. • Radiologically characterized by bilateral & peripheral pulmonary shadowing (photographic negative of pulmonary oedema) with peripheral eosinophilia & high ESR & Ig. E. • Treatment is with steroids.

Tropical pulmonary eosinophilia: secondary to a mosquito borne filarial infection with Wuchereria bancrofti or Brugia malayi. • Treatment is with diethylcarbamazine (6 mg/kg/day for 3 weeks).

Pulmonary vasculitis Granulomatosis with polyangiitis (Wegener’s granulomatosis): • an idiopathic disease manifested by a combination of glomerulonephritis, necrotizing granulomatous vasculitis of the upper and lower respiratory tracts, and varying degrees of small-vessel vasculitis. Symptoms: cough, haemoptysis, chest pain, nasal discharge, crusting, otitis media, fever, weight loss & anaemia. CXR: multiple nodules & cavitation ( mimicking pulmonary tumours or abscess in the lung). Lung biopsy: necrotising granulomas and necrotising vasculitis. Complications: tracheal subglottic stenosis and saddle nose deformity.

Eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome) • an idiopathic multisystem vasculitis of small and medium-sized arteries that occurs in patients with asthma. It can be part of a spectrum that includes polyarteritis nodosa. • The skin and lungs are most often involved, but other organs, including the paranasal sinuses, the heart, gastrointestinal tract, liver, and peripheral nerves, may also be affected. • Peripheral eosinophilia greater than 1. 5 × 109/L or greater than 10% of peripheral WBCs is the rule. • CXR-transient opacities, multiple nodules. • The diagnosis requires demonstration of histologic features, including fibrinoid necrotizing epithelioid and eosinophilic granulomas.

• Treatment of pulmonary vasculitis is glucocorticoids & chemotherapy.

Goodpasture’s disease: • A syndrome of pulmonary haemorrhage & glomerulonephritis with Ig. G antibodies attached to glomerular or alveolar basement membrane. The incidence is higher in smoker males. • Pulmonary manifestations are proceeding renal involvement with hypoxia and/or haemoptysis associated with pulmonary infiltrates on CXR.

Connective tissue diseases & pulmonary involvement Rheumatoid diseases: • Lung involvement appears within 5 years of rheumatoid disease onset but it can be earlier manifestation in 10 -20% of patients. • Pulmonary manifestations are pulmonary fibrosis, non-specific interstitial pneumonia, rheumatoid nodules ( multiple, subpleural), Caplan’s syndrome ( rheumatoid nodules & pneumoconiosis), bronchitis & bronchiectasis, crico-arytenoid arthritis, stridor, pleural effusion, pneumothorax. • Treatment-related side effects (methotrexate-pulmonary fibrosis, anti-TNFreactivation of TB).

Systemic lupus erythematosus: • Pleuro-pulmonary involvement is very common & can be a presenting feature of SLE. • Pleural manifestations- very common (up to two thirds of patients) with repeated episodes of pleurisy &/or effusion with possible pericardial involvement. • Acute alveolitis-life threatening diffuse alveolar haemorrhage requires rapid supportive treatment, immunosuppression & glucocorticoids. • Others- pulmonary fibrosis, shrinking lung (SOB with elevated diaphragm due to diaphragmatic myopathy) & pulmonary thromboembolic disease (SLE & Antiphospholipid syndrome).

Systemic sclerosis: • Pulmonary fibrosis- 90% of patients mainly the diffuse form. • Pulmonary hypertension- more common with limited SS (CREST syndrome). • Recurrent aspiration pneumonia- secondary to oesophageal disease. • Hidebound chest- restricted chest wall movement due to extensive skin Involvement.

Occupational lung diseases

Pneumoconiosis Coal worker’s pneumoconiosis: Cause: prolonged inhalation of coal dust causing pulmonary fibrosis through aggregation of alveolar macrophages.

• Classification: • A/ Simple CWP: asymptomatic. • CXR with small radiographic nodules & lung function test is unaffected. • Ceasing exposure prevents progression. • B/ Progressive massive fibrosis: symptomatic ( productive cough (melanoptysis) & SOB) & may end with respiratory failure. • CXR shows masses & cavitation (DDx: TB, lung cancer & polyangiitis & granulomatosis). • Disease is progressive even with ceasing exposure.

Lung diseases due to organic dusts: Hypersensitivity pneumonitis (extrinsic allergic alveolitis) Causes: inhalation of organic dust leading to type III or IV diffuse immune complex reaction with in the alveolar & bronchial walls. Clinical features: more in farmers (farmer’s lung) or pigeon fanciers (bird fancier’s lung) with symptoms related to the extent of exposure to the triggering organic dusts. • Symptoms either acute as influenza-like syndrome or chronic with progressive pulmonary fibrosis.

Investigations: CXR- ill-defined patchy shadowing. HRCT- ground-glass shadowing & consolidations mainly in upper & middle lobes. In chronic cases, CT shows lung volume loss, linear opacities & structural damage. Pulmonary function test- restrictive defect, reduced lung volume & gas transfer. Type I respiratory failure in advanced cases. Serology- searching for positive precipitin antigen.

Clinical predictors: • • • Exposure to a known offending antigen Positive precipitating antibodies to offending antigen Recurrent episodes of symptoms Inspiratory crackles on examination Symptoms occurring 4– 8 hours after exposure Weight loss

Management: 1. 2. 3. 4. Avoid exposure to possible triggers. Wearing masks. Glucocorticoids. O 2 therapy. Complications: Pulmonary fibrosis, respiratory failure, pulmonary hypertension & right side heart failure.

Thank you