|Year : 2021 | Volume
| Issue : 4 | Page : 274-277
Bird Fancier's lung disease in a child with chronic respiratory illness
Muthuvel Balasubramaniyan1, Joseph L Mathew1, Pankaj C Vaidya1, Kushaljit S Sodhi2, Meenu Singh1, Ashim Das3
1 Department of Pediatrics, PGIMER, Chandigarh, India
2 Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh, India
3 Department of Histopathology, PGIMER, Chandigarh, India
|Date of Submission||28-Oct-2021|
|Date of Decision||29-Oct-2021|
|Date of Acceptance||30-Oct-2021|
|Date of Web Publication||29-Nov-2021|
Dr. Joseph L Mathew
Department of Pediatrics, Advanced Pediatrics Centre, PGIMER, Chandigarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Balasubramaniyan M, Mathew JL, Vaidya PC, Sodhi KS, Singh M, Das A. Bird Fancier's lung disease in a child with chronic respiratory illness. Indian Pediatr Case Rep 2021;1:274-7
|How to cite this URL:|
Balasubramaniyan M, Mathew JL, Vaidya PC, Sodhi KS, Singh M, Das A. Bird Fancier's lung disease in a child with chronic respiratory illness. Indian Pediatr Case Rep [serial online] 2021 [cited 2022 Jan 20];1:274-7. Available from: http://www.ipcares.org/text.asp?2021/1/4/274/331384
Bird fancier's lung is a type of hypersensitivity pneumonitis and rare interstitial lung disease in children. It has 3 forms of presentation viz. acute, subacute, and chronic. Here we present a child with chronic hypersensitivity pneumonitis secondary to pigeon exposure. A 12-year-old boy belonging to a family of pigeon breeders developed cough and dyspnea for two years. On evaluation, he had features of interstitial lung disease with pulmonary arterial hypertension. The diagnosis was confirmed on lung biopsy which showed features of chronic hypersensitivity pneumonitis. The child was managed with oral steroids, oral sildenafil and advised to avoid further exposure to pigeons, to which he responded. Clinicians will benefit from obtaining a detailed environmental history and making diligent efforts to identify the inciting agent and prevent further exposure.
Hypersensitivity pneumonitis (HP) is a chronic respiratory disease in children. It is a condition caused by exposure to various inhaled agents such as agricultural dust, bio-aerosols, fungal, bacterial, or protozoan microorganisms, and certain reactive chemicals. The two major inciting allergens are bird (avian) allergens and inhaled particles derived from fungi. The diagnosis is often missed due to its rare occurrence, subtle symptoms and signs, and poor awareness among physicians. Here, we discuss the clinical approach to a child with chronic respiratory illness, who was subsequently diagnosed as a case of HP, secondary to pigeon exposure.
| Clinical Description|| |
A 12-year-old male child from a rural background presented to our institution with cough and intermittent episodes of low-grade fever for 2 years. The cough was dry, nonparoxysmal, more during waking hours, and absent during sleep. There was no associated wheezing. The fever was of moderate grade (albeit never documented), appeared for a few hours several days at a time, and not associated with any other symptoms. He had developed breathlessness during the last 6 months. Initially, it was on exertion; however, by 2 months before presentation, it had progressed to occurring at rest. There was decreased appetite and loss of weight for 2 months. There was no history of any swelling, facial puffiness, noisy breathing, palpitations, or fainting. There was no significant medical history before this illness. No one in the family had tuberculosis (TB). Since the onset of symptoms, the child had received multiple antibiotics, nebulization with bronchodilators, and a complete course of empiric anti-tuberculosis therapy. He was the fifth-born child of a nonconsanguineous marriage and a student of class V, with normal development history. His father was a farmer. There were no pet animals in the household.
At admission, the child had signs of respiratory failure with heart rate of 132/minute, respiratory rate 42/minute, intercostal retractions, and transcutaneous oxygen saturation of 84% in room air. His weight was 32 kg (−1.04 Z score) and height was 148 cm (−0.37 Z score). On general examination, there was pallor and grade 3 pandigital clubbing, but no cyanosis (on oxygen), significant lymphadenopathy, pedal edema, or elevated jugular venous pressure. Throat, ear, and nasal cavity examinations were normal. Chest examination showed symmetric shape and expansion, centrally positioned trachea, and normal percussion notes in all areas. Bilateral crackles and wheezing were heard on auscultation. The second heart sound was loud but not palpable. There was absence of parasternal heave, splitting, or any murmur. Examination of other systems was normal. The child was stabilized with oxygen delivered through nasal prongs and intravenous fluids. Broad-spectrum antibiotics were started empirically, and a posteroanterior chest radiograph was ordered.
What clinical differential diagnoses can be considered?
The clinical phenotype is that of a chronic respiratory illness with clubbing and probable pulmonary hypertension. Thus, the differentials that should be considered include complicated pulmonary TB, human immunodeficiency virus (HIV) infection, and acquired childhood interstitial lung disease (ILD). ILD could be due to environmental exposure, i.e. HP or systemic causes such as sarcoidosis, connective tissue diseases, anti-neutrophilic cytoplasmic antibody associated, or cystic fibrosis. Though less likely, cytomegalovirus or fungal infection can also be considered. A hyperimmune state like Langerhans cell histiocytosis would be kept lower down, the points against this being the chronic duration of symptoms and absence of other clinical indicators. Diagnoses that could be excluded clinically at this point were acyanotic congenital heart diseases with left-to-right shunts, aspiration syndromes, major congenital lung or airway malformations (late presentation), and primary immune deficiency disorders (normal growth with the absence of recurrent infections and nonrespiratory symptoms).
What are the salient features in the chest X-ray?
The X-ray appears well positioned with adequate exposure [Figure 1]. Visualization of only five intercostal spaces bilaterally indicates hypoinflation. Diffuse reticulonodular opacities are visible in both lung fields. The cardiac silhouette is normal, but the pulmonary bay is not visible. The pleural spaces, trachea, bones, and soft tissues are normal. These radiographic features and the clinical background suggest ILD of childhood onset. However, disseminated TB, cytomegalovirus infection, and causes of secondary immunodeficiency must be excluded.
|Figure 1: Chest X-ray showing hypoinflation with bilateral reticulonodular opacities|
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Complete blood count showed normal hemoglobin (15.6 g/dl), total leukocyte count (11.5 × 109/L), and platelet count (313 × 109/L). The differential count showed 60% neutrophils, 28% lymphocytes, 10% eosinophils, and 2% monocytes. The absolute eosinophil count was 1.15 × 109/L and ESR 10 mm. The tuberculin skin test was nonreactive. Induced sputum specimens were negative for TB on smear and GeneXpert. HIV serology was nonreactive.
On account of peripheral eosinophilia, eosinophilic lung diseases were also considered. Total serum IgE level was elevated (2400 IU/L). Stool examination did not show parasitic ova or cysts. Serology for helminthic infestations was negative for Ascariasis, Filariasis, Strongyloides, and Trichuris. Echocardiography ruled out structural heart disease and confirmed moderate pulmonary artery hypertension (PAH). Spirometry could not be performed as the child was breathless even at rest.
What should be the next line of investigations?
Ideally, a flexible fiberoptic bronchoscopy should be done for bronchoalveolar lavage (BAL) analysis. However, the child was too unstable for such an invasive procedure requiring sedation and analgesia. Therefore, computed tomography (CT) scan of the thorax was planned.
What are the salient findings in the computed tomography scan of the thorax?
The contrast-enhanced CT scan [Figure 2] showed bilateral diffuse ground-glass opacities with lingular bronchiectasis and dilated pulmonary artery. Mild cardiomegaly and mediastinal lymphadenopathy were noted. These features were suggestive of (but, not pathognomonic) of ILD with secondary PAH, but the specific type was not discernible.
|Figure 2: High-resolution computed tomography chest showing bilateral diffuse ground-glass opacities (a), Mediastinal lymphadenopathy (b), and dilated main pulmonary artery (c) Depicted by red arrows in the respective panels|
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What should be done next to determine the diagnosis?
We decided to broaden the workup for known causes of diffuse ILD with peripheral eosinophilia and elevated IgE, such as chronic eosinophilic pneumonia and HP. Specific tests for Wuchereria bancrofti, Toxoplasma gondii, Toxocara canis, Trichinella, and Echinococcosis granulosus, were negative. A nonreactive skin prick test for Aspergillus fumigatus hypersensitivity and normal Aspergillus-specific IgE levels ruled out allergic broncho-pulmonary aspergillosis. Despite the relatively unstable condition of the child, we proceeded with fiberoptic bronchoscopy (after counseling the parents and taking all precautions and high-risk consent) to reach a diagnosis. This showed normal airway anatomy and absence of lingular bronchiectasis. BAL revealed 230 cells with lymphocytic predominance but no eosinophils. Thus, eosinophilic lung diseases were no longer considered likely. Microbiologic examination for bacterial, mycobacterial, fungal, and atypical infections (Mycoplasma, pneumocystis) were negative.
Since the only differential that remained was HP, we decided to revisit the clinical history. Probing to identify potential causes of hypersensitivity uncovered the fact that pigeons were being bred at home for a couple of years, with occasional active involvement of the child. Based on this lead, IgE for avian antigen was ordered, but it was negative. Thus, no other option remained, but to perform an open lung biopsy under general anesthesia with high-risk consent. This revealed fibrosis with peribronchiolar mononuclear infiltrates and well-formed epithelioid granulomas, highly suggestive of chronic HP [Figure 3].
|Figure 3: Histopathological section of the lung tissue showing well-formed epithelioid granuloma and mononuclear infiltrates highlighted by the black arrow|
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Management and outcome
The child was started on oral prednisolone (1 mg/kg/day) and oral sildenafil (2 mg/kg/day) for the PAH. Over the next 3 weeks, his O2 requirement improved significantly, and he could be weaned off it within 4 weeks. Dyspnea improved from New York Heart Association (NYHA) Class 4 to NYHA Class 3 at the time of discharge. The family was advised to avoid further exposure to the pigeons. On follow-up, the child showed further improvement of respiratory symptoms, and hence, steroids were tapered and stopped over 8 weeks.
| Discussion|| |
This case highlights the importance of environmental and occupational exposure to allergens in children with chronic respiratory symptoms. Though uncommon, isolated chronic pulmonary manifestations with features of ILD should prompt the clinician to consider HP. Childhood onset ILD is of three types: (i) related to exposure/environmental insults; (ii) systemic disease processes; and (iii) primary lung parenchyma dysfunction. Since exposure-related lung diseases are less common in children compared to adults, pediatricians may miss making the diagnosis.
HP is an immune-mediated ILD that predominantly involves the distal lung. It occurs due to repeated exposure to specific antigens, both organic and nonorganic. In children, the most common etiology is bird antigen, especially that of pigeons. The pathogenesis is very complex, including immune complex-mediated (type 3) and delayed hypersensitivity (type 4). Children usually present with cough, dyspnea, and cyanosis and are often misdiagnosed and managed as poorly controlled bronchial asthma. When compared with adults, anorexia and weight loss are more pronounced. There are no well-defined diagnostic criteria for children, unlike for adults. Therefore, the diagnosis is usually based on typical symptoms, clinical signs, history of exposure, consistent radiological findings, lymphocytosis on BAL analysis, characteristic histopathological features, and clinical improvement after elimination of the antigen. Our patient displayed all of these features.
BAL may show lymphocytic predominance (>20%) but can be normal as well. A low lymphocyte CD4:CD8 ratio is suggestive of HP, but this is nonspecific and insensitive, especially since children can normally have a low CD4:CD8 ratio. High-resolution CT findings include ground-glass opacities (reported as 40%–93% in various studies), traction bronchiectasis, micronodules, honeycombing, and mediastinal lymphadenopathy. These findings may correlate with the duration. Air trapping mosaicism is seen in acute subtypes; ground-glass opacities in both acute and chronic forms; and fibrosis, interstitial thickening, and traction bronchiectasis in chronic HP. Characteristic histopathological features of granulomatous interstitial pneumonia include a triad; chronic inflammatory infiltrates along small airways, diffuse interstitial infiltrates of chronic inflammatory cells, and scattered small nonnecrotizing granulomas. The index case exhibited all three, but one should note that this is not found in all cases.
Most children have acute to subacute presentations. Very few cases have been reported with chronic forms.,, The primary modality of treatment is total avoidance of the inciting allergen and systemic corticosteroids. Earlier, the treatment is started, better the outcomes. The prognosis is more favorable compared to adults, and mortality is rare.
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.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]