Over Diagnosis of Allergic Bronchopulmonary Aspergillosis (ABPA) Cases as Pulmonary Tuberculosis

Allergic Bronchopulmonary Aspergillosis (ABPA) is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus clinically manifesting as chronic asthma, recurrent pulmonary infiltrates and bronchiectasis^{1, 2}. Despite a high prevalence of ABPA reported in hospital studies from India, ABPA is still under recognized and under diagnosed in our country. ABPA is mostly misdiagnosed as pulmonary tuberculosis as the radiological lesions of ABPA are mimicking those of pulmonary tuberculosis.

The aim of this study is to evaluate the clinical and radiological features and to perform the required investigations in suspected cases of ABPA. Special emphasis is laid on present or past history of Ant tubercular treatment. Ours is a cotton growing area. This can be one of the reasons of many ABPA patients in our area.

Prospective recruitment of all the bronchial asthma patients suspected as ABPA attending Chest and TB department at G.G.S. Medical College, Faridkot during 2010–11.

We enrolled 50 suspected cases of ABPA in our study based on clinical and radiological features. History of present or past intake of ATT was enquired from all patients. The required investigations for ABPA according to the criteria for diagnosis of ABPA were performed.^{2, 3}

Out of 50 suspected cases of ABPA enrolled, all were fulfilling at least five criteria of diagnosis of ABPA. All 50 patients were asthmatics. The predominant symptoms in our study were cough and breathlessness in 100% and 80% of cases respectively. Other symptoms were wheeze and off and on fever in 50% of cases. Hemoptysis was present in 12% of cases. 58% of patients were misdiagnosed as pulmonary tuberculosis and were taking or had taken ATT in the past. Out of 58% of cases, 17% were presently on ATT and 83% had past history of ATT. Out of these 83% cases who had taken ATT in the past, 75% had taken ATT once, 17% twice and 8% had even taken ATT thrice.

ABPA is mostly misdiagnosed as pulmonary tuberculosis as most of the symptoms and radiological lesions were similar to those in pulmonary tb. Misdiagnosis leads to delay in treatment of ABPA cases which leads to complications like bronchiectasis and fibrosis. It also unnecessarily predispose the patients to anti tubercular therapy and eventually the patient may develop unwanted side effects due to ATT. Asthmatic patients having radiographic infiltrates or bronchiectasis on CXR should further be investigated for ABPA.