29M w severe persistent asthma p/w recurrent exacerbations despite optimal LABA/intranasal steroids. Abs eos 1250, total Ig E 1500, CT +mucus plugging, central bronchiectasis upper-middle lobes. Originally from Mexico, now in Texas. Which of the ff tests is indicated?
1/10
Great job! The majority got the right answer, allergic bronchopulmonary aspergillosis (ABPA).
Recurrent asthma exacerbations despite optimal asthma therapy & eosinophilia a/w mucus plugging and multilobar central bronchiectasis should raise suspicion for ABPA.
2/10
Aspergillosis, classified as saprophytic (aspergilloma), allergic (ABPA, hypersensitivity pneumonitis, allergic sinusitis), or invasive (pulmonary, other organs).
ABPA: hypersensitivity to A. fumigatus; can also occur from other fungi (referred as ABPM, M for mycosis).
3/10
Pathogenesis is poorly understood. Involves induction of Th2 predominant response to A. fumigatus in genetically predisposed individuals. Eosinophilic response causes airway damage.
4/10
Frequent asthma exacerbation, most common Sx. May have fever/new infiltrates, can mimic many causes of pneumonia.
Dx rests on a high suspicion for ABPA; requires a predisposing factor, & lab/radiologic features👇 bit.ly/2RhCgZi
5/10
Fleeting CXR infiltrates👇 is characteristic; seen 40-77% of patients but not specific. bit.ly/33pDgjE
Transient ("migratory") infiltrates may be seen in Loeffler’s, lupus pneumonitis, cocaine smoking, COP, radiation pneumonitis, etc bit.ly/3htY4vf
6/10
Bronchiectasis is also not specific (seen in asthma w/o ABPA). Findings of central bronchiectasis (affecting medial 1/2 - 2/3 of lung) in ≥3 lobes & high-attenuation mucoid (visually denser than paraspinal muscle) 👉 highly suggestive of ABPA. bit.ly/33pDgjE
7/10
Total serum Ig E, most useful test not only for dx but also for follow-up. It is the “pro-BNP” of ABPA exacerbation👇 bit.ly/33pDgjE; doubling signifies exacerbation, while a drop by 35-50% with steroid signifies adequate response to Tx (never normalizes).
8/10
Take note that demonstration of A. fumigatus (sputum, bronchoscopy, biopsy) is not necessary and is not part of routine diagnostics.
There’s quite a list of DDX to keep in mind👇So, choices provided in the MCQ are all reasonable options.
@grepmeded @rabihmgeha @DxRxEdu
9/10
Oral steroid, mainstay of tx. No consensus on dose/duration (months to a year of tapering guided by Ig E). Experts recommend antifungals only after 1st relapse despite steroids bit.ly/2RhCgZi. IDSA recommends steroids+antifungals bit.ly/2RlyvSQ.
10/10
Time for #spacedlearning, on a related topic
Review treatment of invasive aspergillosis👇 from the outstanding tweetorial from ID Fellows Network @ID_fellows @swinndong @NNolanMD @LeMiguelChavez @JonathanRyderMD @DrH_flu @TxID_Edu
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