|Year : 2021 | Volume
| Issue : 1 | Page : 40-42
An interesting case of subacute hypersensitivity pneumonitis
Aishhwarrya Umeshchandara Gurugunti, K Ravi
Department of General Medicine, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
|Date of Submission||26-Sep-2019|
|Date of Acceptance||01-Mar-2020|
|Date of Web Publication||03-Feb-2021|
Dr. Aishhwarrya Umeshchandara Gurugunti
Department of General Medicine, Bangalore Medical College and Research Institute, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
Hypersensitivity pneumonitis (HSP) is the paradigm of lung response to inhaled organic and inorganic substances. It is a relatively rare disease, constituting 2% of cases of interstitial lung diseases. We describe a case of a 55-year-old female with a history of breathlessness, fever, and cough with expectoration for 1 month. She gave a history of similar such episodes on and off for the past 7 years. She was diagnosed with pulmonary tuberculosis 6 years back and was treated, but her breathlessness continued to occur despite treatment. Further workup was suggestive of HSP. The later history of exposure to poultry dust was elicited. She was started on steroid pulse therapy along with maintenance dose, which resulted in symptomatic improvement. She underwent a bronchoscopy and the bronchoalveolar lavage, and a diagnosis of subacute HSP was made. HSP can be mistaken for pulmonary tuberculosis and wrongly treated with antitubercular therapy unless the patient is probed about exposure to various inciting antigens.
Keywords: Bronchoalveolar lavage, bronchoscopy, hypersensitivity pneumonitis
|How to cite this article:|
Gurugunti AU, Ravi K. An interesting case of subacute hypersensitivity pneumonitis. APIK J Int Med 2021;9:40-2
| Introduction|| |
Hypersensitivity pneumonitis (HSP), also known as extrinsic allergic alveolitis, is a complex syndrome caused by exposure to a wide variety of organic particles small enough to reach the alveoli (=5 μmm). Subacute HSP develops when HSP continues beyond the acute phase (i.e., continues for weeks to months) and still has the potential to resolve with treatment. While some publications suggest that the disease needs to prevail for between 1 and 4 months to fall into this category, it is important to realize that the terms acute, subacute, and chronic lie on a continuum.
| Case Report|| |
A 55-year-old female with a medical history of hypertension for 2 years presented to casualty with a history of breathlessness for 1 month, fever for 1 month, low grade, with evening rise of temperature, and history of cough for 1 month, with expectoration of white mucoid sputum of moderate amount. She gave a history of similar such episodes on and off for the past 7 years. She was a nonsmoker and was a homemaker by occupation. She lived in a congested urban area in KG Halli in Bengaluru. She was diagnosed with pulmonary tuberculosis 6 years back based on radiographic findings (i.e., sputum-negative pulmonary tuberculosis) with completion of 6 months of antitubercular therapy, but her shortness of breath continued to occur in episodes despite treatment. On examination, she had bilateral basal Velcro crackles. Chest X-ray showed bilateral lower lobe infiltrates left more than right [Figure 1].
Complete blood count revealed eosinophilia. Sputum was negative for acid-fast bacilli, and the cartridge-based nucleic acid amplification test was negative. High-resolution computed tomography [Figure 2] of the chest revealed irregular reticular opacities with patchy ground-glass opacities throughout both lungs with upper lobe predominance and traction bronchiectasis in the left upper lobe. Pulmonary function test showed a restrictive pattern suggestive of HSP.
She had no pets at home, but on further probing, she revealed that there was a poultry near her home, i.e., within 100 m of her window, there were stacks with chicken placed for butchering with a lot of dust emanating from the place. She also reported the symptoms to aggravate during seasons with excessive chicken import.
Course in hospital
She was started on steroid pulse therapy along with maintenance dose, which resulted in symptomatic improvement within 7 days of initiation. She underwent a bronchoscopy, and the bronchoalveolar lavage showed lymphocytosis of 34%, with no growth on cultures. A two-dimensional echocardiogram showed mild pulmonary hypertension. A diagnosis of subacute HSP was made based on the diagnostic criteria. In this case, it was based on the history of significant allergen exposure, clinical and radiological features, as well as bronchoalveolar lavage reports. The patient is currently symptomatically better, off the steroids, and in a new home. In the follow-up after 4 months, her chest X-ray showed a significant resolution of the opacities.
| Discussion|| |
The first cases of HSP were described at the beginning of the 20th century in farmers exposed to hay or straw. Since then, it has been attributed to the inhalation of various antigens found in the environment. Many outbreaks were reported since then.,
The clinical features and severity of symptoms vary according to the frequency and intensity of exposure. A history of exposure to potential agents or changes in the domestic and other environments (or both) is essential to diagnosis and treatment. The interval between exposure to the antigen and clinical manifestations of lung disease is unknown, although symptoms can occur as soon as 4–12 h after exposure. In more chronic and low-level exposures, however, the onset is insidious.
HSP is an underdiagnosed entity; therefore, its exact prevalence is unknown. In addition, the diagnosis is sometimes particularly difficult, since the clinical picture is not specific. In our case, the history of exposure to allergen was obtained on probing and was given later.
Further, avoidance of exposure to the antigen or antigens and treatment with corticosteroids is important if improvement is to be obtained. Continued exposure to the unidentifiable antigens or prolonged exposure to antigens, or both, has led to chronic HSP and irreversible fibrosis that may not respond to any treatment regimen.
The classical system of classification divided HSP into acute, subacute, and chronic. However, the newer systems prefer acute and chronic.
Nonspecific interstitial pneumonia (NSIP) is a chronic interstitial pneumonia that is characterized by a homogeneous appearance of dense or loose interstitial fibrosis with mild-to-moderate chronic interstitial inflammation. NSIP can be idiopathic or can be seen in association with connective tissue disease, HIV infection, a variety of drugs, and HSP. When idiopathic, NSIP is considered one of the idiopathic interstitial pneumonias. However, as the patient responded to the steroid pulse and removal of allergen with significant resolution of clinical and radiological features, with normal antinuclear antibody profile, the diagnosis of HSP was considered more appropriate in this case.
Such cases can be mistaken for pulmonary tuberculosis and wrongly treated with antitubercular drugs unless the patient is probed about exposure to various inciting antigens.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Selman M. Hypersensitivity pneumonitis. In: Interstitial Lung Disease. Schwarz M, King TE Jr., editors. 5th
ed. Shelton, USA: CT: People's Medical Publishing House; 2011. p. 238-50.
Hirschmann JV, Pipavath SN, Godwin JD. Hypersensitivity pneumonitis: A historical, clinical, and radiologic review. Radiographics 2009;29:1921-38.
Gupta A, Rosenman KD. Hypersensitivity pneumonitis due to metal working fluids: Sporadic or under reported? Am J Ind Med 2006;49:423-33.
Hodgson MJ, Bracker A, Yang C, Storey E, Jarvis BJ, Milton D, et al
. Hypersensitivity pneumonitis in a metal-working environment. Am J Ind Med 2001;39:616-28.
Richerson HB, Bernstein IL, Fink JN, Hunninghake GW, Novey HS, Reed CE, et al
. Guidelines for the clinical evaluation of hypersensitivity pneumonitis. Report of the subcommittee on hypersensitivity pneumonitis. J Allergy Clin Immunol 1989;84:839-44.
Vasakova M, Morell F, Walsh S, Leslie K, Raghu G. Hypersensitivity pneumonitis: Perspectives in diagnosis and management. Am J Respir Crit Care Med 2017;196:680-9.
Travis WD, Costabel U, Hansell DM, King TE Jr., Lynch DA, Nicholson AG, et al
. An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classifi?cation of the idiopathic interstitial pneumonias. Am J Respir Crit Care Med 2013;188:733-48.
[Figure 1], [Figure 2]