| What is eosinophilic lung disease? | Eosinophilic lung diseases are heterogenous etiologies with increased nb of eosinophils in airways or parenchyma
May or may not accompany peripheral eosinophilia. |
| What are the classifications of eosinophilic lung disease? | Airway disorders and Interstitial disorders
Airway: Asthma, eosinophilic bronchitis, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis.
Interstitial disorders :
Primary (idiopathic, simple eosinophilia, chronic eosinophiic pneumonia, acute eosinophilic pneumonia)
Secondary (To cause, bacterial (brucellosis, mycobacteria), fungal (pneumocystisis, aspergillus), parasites. Idiopathic lung fibrosis (ILD, sarcoidosis, Lupus, granuloma) others (hypereosinophilic syndrome, pulmonary vasculitis, Hodgkins disease, lung cancer, drugs...) |
| What is the eosinophil? | A leukocyte containing eosin-specific granule, red stained
A tissue cell (300 times> blood), settles in submucosal areas of organs exposed to environment (lungs, GI, GU)
Function is host defense against parasites, modulator of inflammation, tissue destructive cell |
| What are the airway eosinophilic lung diseases? | Asthma, Eosinophilic bronchitis, Fungus-induced asthmatic reaction, allergic bronchopulmonary aspergillus |
| What is eosinophilic asthma? | Eosinophilia present in asthmatic pt, intrinsic or extrinsic, Eosinophil count can be used to assess it (linear relationship between it and inflammation/ airflow limitation. |
| What is eosinophilic bronchitis? | Cause of chronic cough, high percentage of eosinophils in sputum (40%), steroid responsive.
No airflow limitation or bronchial hyperresponsiveness (unlike asthma) |
| What is fungus-induced asthmatic reaction? | Inhalation of fungal spores by asthmatic, IgE mediated allergic rhinitis and asthma and bronchopulmonary mycosis.
Response of fungus resembles exposure to another allergen like dust mites (IgE mediated asthma), non infectious.
Allergic mycosis is infectious, persistent fungal growth or colonization of RT)
Both longstanding asthmatic manifestation. |
| What is allergic bronchopulmonary aspergillosis? | Most common allergic bronchopulmonary mycosis, aspergillus colonizes the airway.
Pt with CF are susceptible
Hyphae persists in airway and release Ag combine with IgG and IgE cause tissue damage, which may be permanent (bronchiectasis) and irreversible airway obstruction. |
| What are eosinophilic parenchymal diseases? | Interstitial lung disease, pulmonary vasculitis. |
| What are eosinophilic interstitial lung diseases? | Increased BAL eosinophils present in 10-20% of ILD, include idiopathic pulmonary fibrosis (poor prognosis and response to Rx)
Also sarcoidosis, lupus, eosinophilic granuloma |
| What are etiologies of pulmonary vasculitis? | Occurs in 1ary systemic vasculitis, SLE, polymyositis, lymphoma, sarcoidosis, extrinsic allergic alveolitis.
1ary vasculitis processes: giant cell arthritis, pulmonary capillaritis, takayaso arteritis, circulating Ab to neutrophils (Churg-strauss, Wegner, polyangiitis) |
| What is Churg-Strauss syndrome? | AKA allergic granulomatosis and angiitis.
Rare distinctive disorder, long standing asthma, dramatic peripheral eosinophilia.
Granulomatous inflammation leading to vascular necrosis affecting lungs.
diagnosis done by open lung biopsy |
| What is the pathophysiology of Churg-Strauss? | Immune complex deposition of small and medium sized arteries and veins
Role of ANCA (anti-neutrophil cytoplasmic antibody)
Clinical features: atopic asthma, fever, malaise, weight loss. |
| What are the systemic manifestations of Churg-Strauss? | Upper airway involvement (sinusitis, rhinitis, nasal polyps)
Skin changes (nodules, purpura, utricaria)
Arthralgias, myalgias, mononeuritis multiplex.
Abdominal symptoms (pain, diarrhea, bleeding)
Cardiac findings (heart failure, pericarditis, HTN)
Microscopic hematuria. |
| What are the imaging findings in Churg-Strauss? | CXR: patchy transient infiltrates.
CT: subpleural consolidation, centrilobular ground-glass opacity, multiple nodules, bronchial wall thickening
Pleural effusion (1/3 of cases, exudative typically with eosinophilia) |
| What are lab findings in Churg-Strauss? | Leukocytosis (eosinophilia, increased ESR, anemia)
IgE increased correlates to disease activity
+ p-ANCA 44-66% (for wegner c-ANCA seen) |
| What are the clinical phases of Churg-Strauss? | Prodromal phase (asthma, allergic rhinitis)
Peripheral eosinophilia and eosinophilic tissue infiltration resmebling loeffler syndrome (chronic eosinophilic pneumonia)
Life-threatening vasculitis |
| How is the management of Churg-Strauss? | Without Rx: 50% die in 3 months (myocardial involvement)
With corticosteroid: live 9 years (alone effective)
Cyclophosphamide reduce relapse (not survival)
Refractory pt need methylprednisone, cyclophosphamide...
Separate Churg-Strauss from other necrotizing vasculitis that need cytotoxic agents. |
| What are parasitic eosinophilic diseases? | Pulmonary infiltrates with eosinophilia with parasites (ascaris, strongyloides...)
When eosinophils present in lungs with no parasites this suggests an immunologic mechanism.
GI symptoms dominate, respiratory symptoms include cough, wheezing and resolves with Rx directed at the parasite.
Most serious one is filarial worm Wuchereria bankrofti and Burgia in india, africa or south america.
Intense inflammation by microfilariae (cough, dyspnea, weight loss...)
Rx is diethylcarbamazine (may lead to fibrosis or chronic bronchitis with chronic respiratory failure) |
| What is idiopathic hypereosinophilic syndrome? | Rare illness of unknown etiology, affects multiple organ systems, result of infiltration of mature eosinophils.
Peripheral eosinophilia (>1500 for 6 months)
Various organ damage
No parasite/ fungus/ allergy...
Could be fatal if cardiac involvement (endocardial fibrosis, restrictive cardiomyopathy, valvular damage and mural thrombosis)
Lung involvement 40% with dry cough and dyspnea
Imaging: pulmonary edema and effusion, interstitial infiltrates (perivascular eosinophilic infiltration)
Oral corticosteroid 50% response.
Busulfan, interferon alpha.... used in steroid irresponsiveness. |
| What is simple pulmonary eosinophilia? | Loeffler's pneumonia, occasional malaise, fever, cough, migratory infiltrates and peripheral eosinophilia (minimal or abscent)
Resolves without Rx within 4 weeks with excellent prognosis
Imaging: migratory peripheral densities.
Etiologies: parasite, drug rxn, idiopathic (1/3 of cases) |
| What is chronic eosinophilic pneumonia? | Uncommon disease, idiopathic, serious condition, middle aged-atopic women typically, insidious respiratory and constitutional symptoms (cough malaise...)
Asthma (50-60%)
Labs: increased IgE, peripheral eosinophilia.
Imaging: diffuse peripheral infiltrates can be diagnostic, negative pulmonary edema)
Biopsy: interstitial and alveolar eosinophilia, microabscesses, vasculitis, interstitial fibrosis
BAL specimen shows eosinophilia, 10% resolve alone.
responds quickly to corticosteroids, becomes asymptomatic within hours or days, but stays on Rx to prevent relapse |
| What is acute eosinophilic pneumonia? | Acute respiratory failure with increased BAL/ eosinophilia , could be hypersensitivity rxn or drug toxicity. Acute febrile illness (5 days duration), hypoxemic respiratory failure, alveolar and interstitial infiltrates, BAL eosinophilia, no infection, rapid complete resolve with corticosteroids, no relapse after stopping steroids
Presents with fever, malaise, myalgia, pleuritic pain, hypoxemia, require ventilation (like ARDS)
BAL provides clue (blood eosinophils normal)
Pleural effusion frequent
Response rapid to steroids (24-48 hours) first high dose then tempered the dose, given for 2-4 weeks
Dx of exclusion |
