Prevalence of allergic bronchopulmonary aspergillosis in asthmatic patients: A prospective institutional study

Background: Allergic bronchopulmonary aspergillosis (ABPA) is characterized by an allergic inflammatory response to colonization by Aspergillus species, most commonly Aspergillus fumigatus.

Aim: To study the prevalence of ABPA in asthmatic patients presenting to our institute.

Materials and methods: All consecutive asthma patients attending our allergy clinic Out Patient Department (OPD) over a period of 20 months were tested with skin prick test (SPT) for Aspergillus antigens and those who were found positive were further evaluated for ABPA using Greenberger's criteria.

Results: Seventy consecutive asthmatic patients were screened by SPT using Aspergillus antigens. Thirteen patients (18.57%) were found to be SPT positive, out of which nine patients (12.9%) were diagnosed as having ABPA using Greenberger's criteria. ABPA was common among 25-35 age group with no gender predilection. ABPA patients had longer duration of illness, predominantly mixed pattern in PFT, higher mean absolute eosinophil count (AEC) and serum total IgE compared to non-ABPA asthmatic patients. Specific IgE for A. fumigatus was positive in all ABPA patients and serum precipitins were positive in seven patients (77.58%). Chest X-ray abnormalities were seen in five patients (55.6%) and HRCT showed central bronchiectasis in eight patients (88.9%) with varying other radiological features. None were sputum fungal culture positive and five patients (55.6%) have been misdiagnosed as pulmonary tuberculosis in the past.

Conclusion: The prevalence of ABPA is significantly higher in bronchial asthma patients presenting to tertiary care centers and hence awareness is required among physicians for early diagnosis and management of ABPA to achieve better asthma control and to avoid permanent lung damage.