Alveolar hemorrhage in patients with rheumatic disease.

Alveolar hemorrhage is an uncommon event that is associated with several underlying disorders, many of which are immunologically mediated. Careful evaluation of basic laboratory tests, extrapulmonary physical findings, and serology usually leads to the correct diagnosis. Significant overlap, however, exists, and pathologic (especially immunopathologic) evaluation of pulmonary or renal biopsies may be necessary. An accurate diagnosis is essential because treatment is most helpful when directed at the underlying diagnosis. Supportive therapy may be needed until the underlying disease is diagnosed and specific therapy is initiated.