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Idiopathic pulmonary hemosiderosis
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- Treatment
- Pulmonary alveolar proteinosis (PAP)
- Course
- Presentation (3 sub-forms) : Acute
- Subacute
Idiopathic pulmonary hemosiderosisrare disease of unknown etiology characterized by episodes of hemoptysis, hemorrhage into the lung, pulmonary infiltration, and secondary iron-deficiency anemia / young children >> adults Ddx: must be distinguished from Goodpasture’s, pulmonary hemorrhage in SLE or Wegener’s Pathology: diffuse infiltration with hemosiderin-containing macrophages is characteristic, although hemosiderin deposition occurs in many other disorders / may get pulmonary capillaritis (neutrophilic infiltration of alveolar septa) Treatment is symptomatic and supportive (death often from massive pulmonary hemorrhage) Course: pulmonary hemorrhages are most often mild and continuous but can be severe. Blood in interstitial spaces leads to pulmonary fibrosis. Patients may live for several years, developing pulmonary fibrosis and insufficiency with chronic secondary anemia. Pulmonary alveolar proteinosis (PAP) [NEJM] 20 to 60 yrs / previously healthy or 2o inorganic dusts / chronic PCP infection, hematologic malignancies, myeloproliferative diseases, or immunosuppression Pathology: limited to the lungs (diffuse or local) / basal, posterior >> anterior segments / alveoli filled with amorphous PAS-positive granules (serum and nonserum proteins) / alveolar lining and interstitial cells are normal / pleura and mediastinum unaffected / lipid concentration in the alveolar spaces is high, possibly because of abnormal clearance of alveolar phospholipids. Presentation: asymptomatic to severe / often gradually progressive exertional dyspnea and cough (usually unproductive) / extrapulmonary symptoms unusual / patients who smoke usu. produce sputum (not diagnostic) Rales: fine inspiratory crackles over affected areas / big rales and persistent fever usually minimal / when present think 2o pneumonia (Nocardia, Mycobacteria, Aspergillus, Cryptococcus sp) Anemia uncommon think diffuse alveolar hemorrhage
Obstructive pulmonary disease is not a feature Labs: polycythemia, hypergammaglobulinemia, increased LDH, increased A-a gradient (intrapulmonary R-L shunt) Treatment: indicated only with significant symptoms and hypoxemia / general anesthesia lungs are lavaged one at a time with 3 to 5 days between lavages most effective is whole-lung lavage via a double-lumen endotracheal tube, with repeated cycles of filling and emptying one lung, using 1 to 2 L of warmed 0.9% NaCl / Some require only one lavage (others require lavage q 6 to 12 mo for many years) Investigational: potassium iodide and proteolytic enzymes (trypsin, streptokinase-streptodornase) steroids unsuccessful and may increase possibility of secondary infection / lung transplant has been used for (fibrosis still can recur) / G-CSF has been used in some patients Course: condition may progress, remain stable, or clear spontaneously / disability common (respiratory insufficiency), death is rare with treatment Hypersensitivity pneumonitis (extrinsic allergic alveolitis) diffuse interstitial granulomatous lung disease – allergy to organic dusts or simple chemicals Etiology/Pathogenesis: foreign animal or vegetable protein > simple chemicals (with a lot of exposure) mostly type IV or delayed-type hypersensitivity reaction (some features of type III) only after weeks to months of exposure chronic progressive parenchymal disease may result from continuous or frequent low-level exposure to the antigen history of allergic disease (e.g., asthma, hay fever) is uncommon and is not a predisposing factor Pathology: diffuse granulomatous interstitial pneumonitis characteristic but not definitive or specific lymphocyte and plasma cell infiltrates occur along airways and in thickened alveolar septa single, nonnecrotizing granulomas randomly scattered in the parenchyma fibrosis depends on the stage of the disease (usually mild) bronchiolitis in ~50% of patients with farmer’s lung Presentation (3 sub-forms): Acute: fever, chills, cough, dyspnea +/- anorexia, nausea, vomiting in previous sensitized person (4-8 h post-reexposure) / +/- rales, (-) wheezing / symptoms improve within hours after stopping exposure, complete recovery days/weeks. Subacute: cough, dyspnea over days to weeks can lead to hospitalization Chronic: progressive exertional dyspnea, productive cough, fatigue, weight loss over months/years (can progress to respiratory failure) Diagnosis: exposure (challenge), clinical, CXR, PFT / can test for Ab to suspected agents but not necessary (can have present but untelling Ig) / last resort is lung biopsy (differentiate from ILD) / BAL might differentiate from sarcoid / can differentiate from infective pneumonias by diagnosing the infection (serology, culture, PCR) / asthma and allergic bronchopulmonary aspergillosis have obstructive PFT’s and eosinophilia CXR: range from normal to diffuse interstitial fibrosis / bilateral patchy or nodular infiltrates (usu. upper lobes) increased interstitial markings or picture of mild edema / usu. does not have hilar lymphadenopathy or effusions HRCT: may help evaluate extent of disease but no pathognomic findings PFT: restrictive pattern with ↓ lung volumes, a ↓ DLco, abnormal VQ, hypoxemia / airway obstruction unusual in acute disease but may develop in chronic disease / (-) eosinophilia Ddx: autoimmune (Hamman-Rich syndrome, IPF, UIP, Wegener’s, LAM, C-S), eosinophilic pneumonia, BOOP, psittacosis, viral pneumonia, other infective Download 3.95 Mb. Share with your friends:
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