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Internal Medicine

Allergic bronchopulmonary aspergillosis (ABPA)

Progressive fungal allergic lung disease, is a common complication of asthma or cystic fibrosis.


Aetiology

  • Aspergillus species: Aspergillus fumigatus
  • Underlying asthma (2.5% cases) or cystic fibrosis (15% cases)

Clinical features

Episodes of bronchial obstruction with mucous plugs leading to coughing fits, pneumonia, consolidation, wheezing, and breathlessness are typical and central bronchiectasis is a characteristic feature.

  • Central bronchiectasis (CHARACTERISTIC)

Diagnosis

Modified ISHAM working group 2013 criteria for diagnosis of ABPA:

  1. Predisposing asthma/CF
  2. Obligatory criteria:
    • IgE > 1000 IU/mL and
    • Positive immediate skin test or increased IgE antibody to Aspergillus
  3. Supportive (≥2) criteria:
    • Eosinophilia > 500
    • Precipitins or increased IgG antibody to Aspergillus
    • Consistent radiographic opacities

Chest radiograph:

  • Finger-in-glove sign (CHARACTERISTIC): Tubular and branching tubular opacities that appear to emanate from the hila, said to resemble gloved fingers

HRCT:

  • Halo sign “signet-ring appearance”: Localized ground glass appearance representing an area of hemorrhagic infarction surrounding a nodule (invasive aspergellosis)
indianjradiolimaging_2011_21_4_242_90680_f15
(A-C) Axial HRCTs (lung window) show the various types of bronchiectasis in three different patients with ABPA: cylindrical bronchiectatic cavities (thin arrow) of various sizes with the characteristic signet-ring appearance (thick arrow) (A), varicose bronchiectasis (arrows in B), and cystic bronchiectasis | Agarwal, R., Khan, A., Garg, M., Aggarwal, A., & Gupta, D. (2011). Pictorial essay: Allergic bronchopulmonary aspergillosis. Indian Journal of Radiology and Imaging, 21(4), 242–252. https://doi.org/10.4103/0971-3026.90680

Management

  • Oral glucocorticosteroids (MAINSTAY, M/effective in acute cases)
  • Antifungal agents (chronic use): Ketoconazole, Itraconazole, Voriconazole and posaconazole
  • Immunotherapy: Omalizumab (monoclonal antibody to IgE)

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