Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 28, Num. 4, 2010, pp. 402-404

Indian Journal of Medical Microbiology, Vol. 28, No. 4, October-December, 2010, pp. 402-404

Case Report

Allergic bronchopulmonary aspergillosis presenting with cavitary lesion and simulating a lung abscess

R Dixit¹, J George¹, PS Nirwan²

¹ Department of Pulmonary Medicine, J.L.N. Medical College, Ajmer, India
² Department of Microbiology, J.L.N. Medical College, Ajmer, India
Correspondence Address:
R Dixit, Department of Pulmonary Medicine, J.L.N. Medical College, Ajmer, India
dr.ramakantdixit@gmail.com

Date of Submission: 25-Sep-2009
Date of Acceptance: 12-Jul-2010

Code Number: mb10119

PMID: 20966583
DOI: 10.4103/0255-0857.71848

Abstract

Keywords: Allergic bronchopulmonary aspergillosis, cavitary pulmonary lesion, lung abscess

Introduction

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologically mediated lung disease that usually occurs in atopic individuals and is caused by hypersensitivity to the antigen of Aspergillus fungus. This disease is characterized by presence of asthma, transient (often fleeting) pulmonary infiltrates, peripheral blood eosinophilia, immediate cutaneous reactivity, precipitating antibodies and elevated serum IgE and IgG to Aspergillus fumigatus, elevated total serum IgE and central bronchiectasis. ^[1] A wide spectrum of chest radiographic appearances has been described in ABPA. ^[2] However, a chest radiographic presentation of a cavitary lesion with air-fluid level simulating a lung abscess has been described very rarely. ^[3] This communication describes a case of ABPA presenting as lung abscess. It is important to be familiar with the wide range of findings in ABPA, since early diagnosis and steroid therapy are important to prevent progressive lung damage that may occur if it is left untreated.

Case Report

A 52-year-old female presented with cough with expectoration and breathlessness for the last three months. There was no fever, chest pain or haemoptysis. She has received two courses of broad-spectrum antibiotics without any improvement before presenting to us. She was diabetic and well-controlled on oral hypoglycaemic agents. She gave history of seasonal and episodic breathlessness associated with wheezing for the last eight years but denied taking any regular treatment for this. There was no history of pulmonary tuberculosis, other prolonged respiratory illness or immuno-suppressive therapy in past.

On examination, she was afebrile with normal vital parameters. There was no pallor, cyanosis, clubbing or lymphadenopathy. Systemic examination including respiratory system was unremarkable.

Her investigations revealed hemoglobin 11 gm, total leukocyte count 6800/mm ³ with 23% eosinophils on differential count, ESR 42 mm in 1 ^st hour, fasting blood sugar 113 mg/dl with normal liver and renal function tests. Her serum was non-reactive for HIV-1 and HIV-2. Skiagram chest PA view showed a cavitary lesion with air-fluid level resembling a lung abscess on right side [Figure - 1]. Sputum smear microscopy for acid-fast bacilli was negative in three samples. Gram staining of sputum smear examination did not reveal any organisms. Sputum was sterile on culture for pyogenic organisms and fungi. On spirometry, there was moderate airflow limitation with significant reversibility 15 minutes after nebulized salbutamol. CT scan thorax showed cavitary lesions with air-fluid levels in right upper lobe <[Figure - 2]. Based on above reports, a possibility of non-infectious process was considered. Patient was subjected to bronchoscopy that was found normal, but bronchial washings showed Aspergillus fumigatus on smear examination as well as on fungal culture [Figure - 3]. Intradermal tests with Aspergillus fumigatus species elicited strong type I hypersensitivity reaction. Total serum IgE level was 3215 IU/ml (normal < 180 IU/ml). Serum IgG and IgE were positive against Aspergillus fumigatus, and raised serum precipitins were also detected against Aspergillus fumigatus. Thus a diagnosis of ABPA was established.

Patient was managed by oral deflazacort therapy (initially 60 mg daily) with close monitoring of blood sugar and inhaled long-acting bronchodilators with corticosteroid therapy. There was marked clinical and radiological improvement. The dose of deflazacort was gradually tapered and maintained on 6 mg at the end of three months. Patient was asymptomatic and a repeat chest X-ray showed complete resolution of the initial abnormality at six months.

Discussion

ABPA is a potentially destructive lung disease, first recognized in the United Kingdom in 1952 ^[4] and since then has been reported worldwide. It is characterized by repeated episodes of exacerbations, periods of remission and if untreated, chronic fibrotic lung disease.

Imaging and immunological methods are usually required for the diagnosis and to monitor the disease progress. A wide range of chest radiographic features has been described in ABPA. ^{[2],[3],[4],[5]} These includes normal chest radiograph, hyperinflation, various infiltrate patterns, consolidation, nodules, avascular areas, toothpaste shadows, gloved-finger shadows, tramline shadows, band shadows, lobar or segmental collapse, parallel line shadows, ring shadows, central bronchiectasis with normal peripheral bronchi, sometime hilar lymphadenopathy, pleural thickening, and in late stages, cavitation, contracted upper lobes and localized emphysema. Presences of small cavities with fluid levels as well as miliary nodules are also described rarely. ^[6],[7] A lung abscess-like presentation is very rare and described only on CT scan previously. ^[3] Our case is unique in view of a lung abscess-like presentation on plain chest radiograph as well as on CT scan. It may have been caused by massive dilatation of the involved bronchus by mucus plug that is resolved with the treatment. In the absence of clinical features of lung abscess and a diagnosis of ABPA based on clinical, immunological, haematological and mycological parameters, patient was treated with oral corticosteroids. The resolution of the lesion resembling a lung abscess, with steroid therapy confirms that this lesion was part of disease process due to ABPA. Gefter and co-workers ^[8] noticed cavitation in 3 out of 14 cases of ABPA and explained this secondary to obstructive atelectasis from mucus plugs representing pos- obstructive abscesses, and in another case due to tissue necrosis within large alveolar infiltrates (presumably representing allergic pneumonia). However, ABPA may also complicate by secondary lung abscesses due to pyogenic infective organisms including Streptococcus pneumoniae sometime. ^[9],[10]

In view of varied radiological presentation of ABPA, clinicians must be vigilant with rare initial presentation such as "lung abscess" so as to avoid wrong diagnosis and treatment. This will also help in early management of these cases to prevent the development of end-stage pulmonary fibrosis.

References

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