Table 3. ABPA Staging, Radiographic Findings, and Corresponding IgE Levels.

ABPA: allergic bronchopulmonary aspergillosis; IgE: immunoglobulin E; CT: computed tomography.

Stage	Description	Radiographic Findings	Total IgE Concentration
Stage I: acute	The patient is diagnosed with ABPA. Some features such as Aspergillus-specific IgE, radiological abnormalities, peripheral blood eosinophilia, and Aspergillus-specific serum precipitins may be seen [12].	There may be homogenous infiltrates, mucus plugging, lobar consolidation or collapse, “tree-in-bud” appearance, bronchiectasis (see Figure 1) [8].	Overall elevated [8]
Stage II: remission	Asymptomatic patient with underlying controlled asthma but no new radiological infiltrates and no rise in total IgE for a minimum of six months [12].	No infiltrates are seen [8].	Normal or elevated IgE level but less than stage I level [8].
Stage III: exacerbation	New pulmonary infiltrates appear on x-ray with peripheral blood eosinophilia and double the remission level IgE levels [12].	The same findings as seen in acute stage  [8].	Elevated IgE levels usually double the level of stage II [8].
Stage IV: steroid-dependent asthma	Patients become dependent on corticosteroid treatment and are unable to completely taper off from it [12].	No infiltrates are seen. There can be atelectasis or hyperinflation from asthma [8]. If exacerbation occurs then the findings will resemble stage I [8].	Normal or elevated IgE level [8].
Stage V: end-stage fibrotic disease	Chest x-ray and CT scans will show irreversible fibrosis and chronic cavitation. Despite this, serological parameters are usually negative [12].	There is lung scarring, hyperinflation, chronic infiltrates, fibrosis or cavities or fibrocavitary findings [8].	Normal or elevated IgE level [8].