Page 269 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Systemic Vasculitis and the Lung 243

Figure 1. Left main bronchial stenoses, visible on bronchoscopy (left image), with beading appearance
on axial CT scan (right image).

Asthma
Asthma is a defining feature of EGPA [9, 10] that usually develops before the onset of

systemic manifestations of vasculitis; it is diagnosed simultaneously in up to 20% of affected
patients [11]. The interval between asthma and EGPA diagnoses is about 8 years, on average,
with a mean age at onset of asthma of 32 years, which emphasizes its relatively late-onset
character. Asthma typically increases in severity in the months to years before the onset of
systemic manifestations of vasculitis and improves when the initial vasculitic manifestations
occur with persistence, even after adequate control of the underlying vasculitis. Many patients
require long-term, low-dose prednisone and inhaled corticosteroids for control of asthmatic
symptoms even after remission of the systemic vasculitis. Whether the characteristics of
vasculitis-associated asthma differ from idiopathic and allergic asthma is not well understood
[12]. No clinical findings or functional tests distinguish these categories of asthma, but as a
rule, late-onset asthma and increasing blood eosinophilia should lead to considering EGPA.

Parenchymal Disease

Vasculitis-related parenchymal lung disease is common in GPA, MPA, EGPA, and anti-
glomerular basement membrane (anti-GBM) disease but also occurs in the LVV giant cell
arteritis (GCA) and the SVV immune complex (IC) disorder, IgA vasculitis/Henoch-
Schonlein purpura (IgAV/HSP) [13].

Alveolar Hemorrhage
Diffuse alveolar hemorrhage (DAH) is a classical manifestation of AAV and occurs in

12% to 32% of patients with MPA and in 8% to 30% of those with GPA, 60% to 80% of
those with anti-GBM or Goodpasture syndrome, and in less than 10% and 2% with EGPA
and IgAV, respectively. The extent and severity of pulmonary capillaritis varies from
clinically silent to shortness of breath and subacute to acute fulminant hemoptysis and
respiratory distress syndrome. Hemoptysis is absent in up to one third of patients with
alveolar hemorrhage, which is diagnosed by the presence of anemia, patchy ground-glass

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