Question

A young boy presented with SOB and wheeze. He was kept in anti-asthmatic medication with no significant improvement. Later he presented with skin lesions and was started on antifungals by the dermatologist which led to improvement in both the skin and respiratory symptoms. Likely diagnosis is?

• A. Allergic bronchopulmonary aspergillosis (ABPA)
• B. Eosinophilic interstitial pneumoina
• C. Chronic pulmonary aspergillosis
• D. fungal pneumonia

Hint:

Diagnostic criteria for ABPA include a history of asthma or cystic fibrosis, elevated total serum IgE (typically $>$ 1000 IU/mL), positive skin prick test or specific IgE for Aspergillus fumigatus, and peripheral blood eosinophilia.
Radiologically, central bronchiectasis is a hallmark complication seen on High-Resolution CT (HRCT) of the chest.

Answer 1

The Correct Option is A

Concept:
The patient is a young boy initially presenting with asthma-like symptoms (shortness of breath and wheezing) that were refractory to standard anti-asthmatic therapies.
He subsequently developed skin lesions, and crucially, treatment with systemic antifungals resolved both his dermatological issues and his refractory respiratory symptoms.
This dual response strongly implicates an underlying fungal etiology driving a hypersensitivity reaction in the lungs.
Explanation:
• Allergic Bronchopulmonary Aspergillosis (ABPA) is a complex hypersensitivity reaction to colonization of the airways by Aspergillus species, most commonly Aspergillus fumigatus.

• It occurs almost exclusively in patients with underlying asthma or cystic fibrosis.

• The continuous presence of Aspergillus antigens in the airways triggers a severe Th2-mediated immune response, leading to high levels of IgE, eosinophilia, and intense airway inflammation.

• Clinically, this presents as severe, poorly controlled asthma with recurrent exacerbations, often accompanied by expectoration of brownish mucus plugs.

• The fact that standard anti-asthmatic medications alone failed is characteristic of ABPA, which requires targeted therapy against the immune response and the fungal burden.

• While systemic corticosteroids are the cornerstone of ABPA treatment to suppress the hypersensitivity reaction, antifungal agents (like itraconazole) are used as crucial adjuncts.

• Antifungals reduce the fungal burden in the airways, thereby removing the antigenic stimulus driving the allergic reaction.

• The patient's coincident fungal skin infection prompted antifungal therapy, which fortuitously treated the underlying Aspergillus colonization in his respiratory tract, resulting in clinical improvement of his wheezing.

• Other options like Eosinophilic interstitial pneumonia do not directly respond to antifungals.

• Chronic pulmonary aspergillosis typically affects adults with pre-existing cavitary lung disease (e.g., prior tuberculosis) rather than presenting as asthmatic wheezing in a young boy.

• Simple fungal pneumonia is an invasive infectious process, usually seen in immunocompromised individuals, presenting with fever and infiltrates, not primarily as refractory wheeze.
Final answer:
The clinical course of refractory asthma responding to antifungal therapy is highly indicative of Allergic bronchopulmonary aspergillosis (ABPA).