Evaluation of progressive pulmonary fibrosis in non-idiopathic pulmonary fibrosis-interstitial lung diseases: a cross-sectional study.

BACKGROUND: Progressive pulmonary fibrosis is the symptomatic, physiological, and radiological progression of interstitial lung diseases. The aim of this study was to examine the relationship between progressive pulmonary fibrosis and demographic characteristics and to evaluate the effect on clinical outcomes and mortality. METHODS: This cross-sectional study included 221 patients diagnosed with non-idiopathic pulmonary fibrosis interstitial lung diseases who were followed in the last 5 years. Patient symptoms, clinical, radiological, and demographic data were examined. Risk factors for the development of progressive pulmonary fibrosis and the relationship with clinical outcomes and mortality were examined. RESULTS: Of the patients, 33.0% (n = 73) had fibrotic idiopathic nonspecific interstitial pneumonia (iNSIP), 35.7% (n = 79) had fibrotic hypersensitivity pneumonia (HP), 18.1% (n = 40) had fibrotic connective tissue disease (CTD) interstitial lung diseases (ILD), and 13.1% (n = 29) had postinfectious fibrotic ILD. The progressive pulmonary fibrosis development rates of the subtypes were 46.5% iNSIP (n = 34), 86.0% fibrotic HP (n = 68), 42.5% fibrotic CTD-ILD (n = 17), and 20.7% postinfectious ILD (n = 6). The presence of progressive pulmonary fibrosis was associated with the development of respiratory failure and mortality (odds ratio [OR]: 2.70, 95% CI: 1.04-7.05 and OR: 2.13, 95% CI: 1.23-3.69). Progressive pulmonary fibrosis development was higher in hypersensitivity pneumonia patients with farmer's lung (OR: 5.06, 95% CI: 1.02-25.18). CONCLUSION: Progressive pulmonary fibrosis was more prevalent in older patients. Farming was an important risk factor in the development of hypersensitivity pneumonia-progressive pulmonary fibrosis. Respiratory failure and mortality were higher in those who developed progressive pulmonary fibrosis.

A first look at the reliability, validity and responsiveness of L-PF-35 dyspnea domain scores in fibrotic hypersensitivity pneumonitis.

BACKGROUND: Dyspnea impairs quality of life (QOL) in patients with fibrotic hypersensitivity pneumonitis (FHP). The Living with Pulmonary Fibrosis questionnaire (L-PF) assesses symptoms, their impacts and PF-related QOL in patients with any form of PF. Its scores have not undergone validation analyses in an FHP cohort. METHODS: We used data from the Pirfenidone in FHP trial to examine reliability, validity and responsiveness of the L-PF-35 Dyspnea domain score (Dyspnea) and to estimate its meaningful within-patient change (MWPC) threshold for worsening. Lack of suitable anchors precluded conducting analyses for other L-PF-35 scores. RESULTS: At baseline, Dyspnea's internal consistency (Cronbach's coefficient alpha) was 0.85; there were significant correlations with all four anchors (University of California San Diego Shortness of Breath Questionnaire scores r = 0.81, St. George's Activity domain score r = 0.82, percent predicted forced vital capacity r = 0.37, and percent predicted diffusing capacity of the lung for carbon monoxide r = 0.37). Dyspnea was significantly different between anchor subgroups (e.g., lowest percent predicted forced vital capacity (FVC%) vs. highest, 33.5 ± 18.5 vs. 11.1 ± 9.8, p = 0.01). There were significant correlations between changes in Dyspnea and changes in anchor scores at all trial time points. Longitudinal models further confirmed responsiveness. The MWPC threshold estimate for worsening was 6.6 points (range 5-8). CONCLUSION: The L-PF-35 Dyspnea domain appears to possess acceptable psychometric properties for assessing dyspnea in patients with FHP. Because instrument validation is never accomplished with one study, additional research is needed to build on the foundation these analyses provide. TRIAL REGISTRATION: The data for the analyses presented in this manuscript were generated in a trial registered on ClinicalTrials.gov; the identifier was NCT02958917.

Hospitalization Rates in Interstitial Lung Disease: An Analysis of the Pulmonary Fibrosis Foundation Registry.

Rationale: Little is known about hospitalization in other types of interstitial lung disease (ILD) besides idiopathic pulmonary fibrosis (IPF). Objectives: To determine the frequency of hospitalizations in various types of ILD and elucidate the association of hospitalization with outcomes. Methods: An analysis of the Pulmonary Fibrosis Foundation Patient Registry data was performed. Inpatient hospitalization rates and survival posthospitalization were compared for various types of ILD. Measurements and Main Results: Hospitalization rates were similar across ILD types: 40.6% of participants with IPF, 42.8% of participants with connective tissue disease-related ILD (CTD-ILD), 44.9% of participants with non-IPF idiopathic interstitial pneumonia (IIP), 46.5% of participants with chronic hypersensitivity pneumonitis (CHP), and 53.3% of participants with "other" ILD. All-cause hospitalization was not associated with decreased transplant-free survival (adjusted hazard ratio [AHR], 1.20; 95% confidence interval [CI] = 0.98, 1.46; P = 0.0759) after adjusting for comorbidities and severity of illness; however, respiratory-related hospitalization was (AHR, 1.53; 95% CI = 1.23, 1.90; P = 0.0001). Participants with CTD-ILD (HR, 0.43; 95% CI = 0.25, 0.75; P = 0.0031) and non-IPF IIP (HR, 0.3; 95% CI = 0.15, 0.58; P = 0.005) had a lower risk of death posthospitalization compared with those with IPF, whereas those with chronic hypersensitivity pneumonitis (HR, 0.67; 95% CI = 0.37, 1.20; P = 0.1747) or other ILD (HR, 0.54; 95% CI = 0.19, 1.54; P = 0.25) had a risk comparable with that for IPF. Conclusions: Rates of hospitalization are similar across ILD subtypes. The risk of death or transplant after posthospitalization is lower in patients with CTD-ILD and non-IPF IIP, compared with patients with IPF. In a mixed population of participants with ILD, all-cause hospitalizations were not associated with decreased transplant-free survival; however respiratory-related hospitalizations were.

Concurrent features of sarcoidosis and hypersensitivity pneumonitis in two patients exposed to fungal antigens.

BACKGROUND: Sarcoidosis and hypersensitivity pneumonitis (HP) are two distinct clinical entities that share granulomatous inflammation, although each of them has specific clinical, radiologic and pathologic profiles. Coexistence of the two diseases have been described, suggesting, at least in some cases, a common biologic background. CASE PRESENTATION: We describe two patients showing the concurrent diagnosis of sarcoidosis and hypersensitivity pneumonitis. Case 1: a 51-year old never smoker man had a history of occupational exposure, episodes of acute exacerbations and positive serum precipitins to Penicillium spp suggestive of HP, while the positivity of serum angiotensin converting enzyme (ACE) favored sarcoidosis. Case 2: a 42-year old non-smoker woman with occasional finding of enlarged mediastinal lymph nodes had a history of domestic exposure to molds and positive serum precipitins to Aspergillus spp suggestive of HP. In both cases high resolution computed tomography (HRCT) together with broncoscopy findings allowed to maintain both the diagnoses: HRCT showed both enlarged hilar/mediastinal limph nodes and intersitial lung involvement typical of HP; bronchoalveolar lavage presented marked lymphocytosis and granulomatous nodal lesions were observed at transbronchial needle aspiration. CONCLUSIONS: Sarcoidosis and HP share some clinical findings and the differential diagnosis may be difficult. Our cases suggest that a common trait may be responsible for the concurrent diagnosis of sarcoidosis and hypersensitivity pneumonitis in the same patient.

Current possibilities of histopathologic separation of idiopathic pulmonary fibrosis from fibrotic hypersensitivity pneumonitis. How to do it?

Histopathological pattern of progressive pulmonary fibrosis could be seen in many different fibrotic lung interstitial diseases. Exact diagnosis is crucial for precise therapy, moreover, different diseases have different prognosis. The most important disorders in this group are idiopatic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis, and their separation is crucial because of totally different treatment of the patients. The aim of this review is to sum up the most important characteristics of usual interstitial pneumonia, histopathological pattern of idiopatic pulmonary fibrosis, and fibrotic hypersensitivity pneumonitis and provide a practical work-up for precise diagnostics of these diseases in the frame of effectively cooperating multidisciplinary team.

Prevalence and characteristics of progressive fibrosing interstitial lung disease in a prospective registry.

BACKGROUND: Progressive fibrosing interstitial lung disease (PF-ILD) is characterised by progressive physiological, symptomatic and/or radiographic worsening. The real-world prevalence and characteristics of PF-ILD remain uncertain. METHODS: Patients were enrolled from the Canadian Registry for Pulmonary Fibrosis between 2015 and 2020. PF-ILD was defined as a relative forced vital capacity (FVC) decline ≥10%, death, lung transplantation or any two of: relative FVC decline ≥5% and <10%, worsening respiratory symptoms or worsening fibrosis on computed tomography of the chest, all within 24 months of diagnosis. Time-to-event analysis compared progression between key diagnostic subgroups. Characteristics associated with progression were determined by multivariable regression. RESULTS: Of 2746 patients with fibrotic ILD (mean±sd age 65±12 years; 51% female), 1376 (50%) met PF-ILD criteria in the first 24 months of follow-up. PF-ILD occurred in 427 (59%) patients with idiopathic pulmonary fibrosis (IPF), 125 (58%) with fibrotic hypersensitivity pneumonitis (HP), 281 (51%) with unclassifiable ILD (U-ILD) and 402 (45%) with connective tissue disease-associated ILD (CTD-ILD). Compared with IPF, time to progression was similar in patients with HP (hazard ratio (HR) 0.96, 95% CI 0.79-1.17), but was delayed in patients with U-ILD (HR 0.82, 95% CI 0.71-0.96) and CTD-ILD (HR 0.65, 95% CI 0.56-0.74). Background treatment varied across diagnostic subtypes, with 66% of IPF patients receiving antifibrotic therapy, while immunomodulatory therapy was utilised in 49%, 61% and 37% of patients with CHP, CTD-ILD and U-ILD, respectively. Increasing age, male sex, gastro-oesophageal reflux disease and lower baseline pulmonary function were independently associated with progression. CONCLUSIONS: Progression is common in patients with fibrotic ILD, and is similarly prevalent in HP and IPF. Routinely collected variables help identify patients at risk for progression and may guide therapeutic strategies.

Chronic hypersensitivity pneumonitis is associated with an increased risk of venous thromboembolism: a retrospective cohort study.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis share commonalities in pathogenesis shifting haemostasis balance towards the procoagulant and antifibrinolytic activity. Several studies have suggested an increased risk of venous thromboembolism in IPF. The association between venous thromboembolism and chronic hypersensitivity pneumonitis has not been studied yet. METHODS: A retrospective cohort study of IPF and chronic hypersensitivity pneumonitis patients diagnosed in single tertiary referral center between 2005 and 2018 was conducted. The incidence of symptomatic venous thromboembolism was evaluated. Risk factors for venous thromboembolism and survival among those with and without venous thromboembolism were assessed. RESULTS: A total of 411 (259 IPF and 152 chronic hypersensitivity) patients were included (mean age 66.7 ± 8.4 vs 51.0 ± 13.3 years, respectively). There were 12 (4.6%) incident cases of venous thromboembolism in IPF and 5 (3.3%) in chronic hypersensitivity pneumonitis cohort. The relative risk (RR) of venous thromboembolism in chronic hypersensitivity pneumonitis was not significantly different to that found in patients with IPF (7.1 vs 11.8/1000 person-years, RR 1.661 95% CI 0.545-6.019, respectively). The treatment with systemic steroids (OR 5.38; 95% CI 1.65-18.8, p = 0.006) and GAP stage 3 (OR 7.85; 95% CI 1.49-34.9; p = 0.037) were significant risk factors for venous thromboembolism in IPF. Arterial hypertension and pulmonary hypertension significantly increased risk of venous thromboembolism in chronic hypersensitivity pneumonitis. There were no significant differences in survival between patients with and without venous thromboembolism. CONCLUSIONS: The patients with chronic hypersensitivity pneumonitis have a marked increase in the risk of venous thromboembolism, similar to the patients with IPF. Venous thromboembolism does not affect the survival of patients with IPF and chronic hypersensitivity pneumonitis.

Activation of Downstream mTORC1 Target Ribosomal Protein S6 Kinase (S6K) Can Be Found in a Subgroup of Dutch Patients with Granulomatous Pulmonary Disease.

Mechanistic target of rapamycin complex 1 (mTORC1) has been linked to different diseases. The mTORC1 signaling pathway is suggested to play a role in the granuloma formation of sarcoidosis. Recent studies demonstrated conflicting data on mTORC1 activation in patients with sarcoidosis by measuring activation of its downstream target S6 kinase (S6K) with either 33% or 100% of patients. Therefore, the aim of our study was to reevaluate the percentage of S6K activation in sarcoidosis patients in a Dutch cohort. To investigate whether this activation is specific for sarcoid granulomas, we also included Dutch patients with other granulomatous diseases of the lung. The activation of the S6K signaling pathway was evaluated by immunohistochemical staining of its downstream effector phospho-S6 in tissue sections. Active S6K signaling was detected in 32 (43%) of the sarcoidosis patients. Twelve (31%) of the patients with another granulomatous disorder also showed activated S6K signaling, demonstrating that the mTORC1 pathway may be activated in a range for different granulomatous diseases (p = 0.628). Activation of S6K can only be found in a subgroup of patients with sarcoidosis, as well as in patients with other granulomatous pulmonary diseases, such as hypersensitivity pneumonitis or vasculitis. No association between different clinical phenotypes and S6K activation can be found in sarcoidosis.

[Adenopathy and mammary carcinoma: It is sometimes in the details that one encounters hypersensitivity pneumonitis!] / Adénopathie et carcinome mammaire : c'est dans les détails que se cache la pneumopathie d'hypersensibilité !

INTRODUCTION: Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to an immunological reaction to exposure, by inhalation, to a large variety of antigens. The patho-physiological mechanism remains poorly understood. The diagnosis can be challenging and requires a detailed medical history taking especially when the clinical presentation is atypical or when the causal agent remains unknown. CASE REPORT: We report the case of a 75-year-old woman with a history of mammary carcinoma who presented with recently identified intramammary adenopathy. Biopsy of the adenopathy revealed non-necrotising, giant cell epithelioid granuloma. A diagnosis of hot tub lung with extra-pulmonary granulomatous lymph node involvement was made based on the clinical, functional, radiological and microbiological investigations. The evolution was favorable following antigen avoidance. CONCLUSION: Extrapulmonary lymph node involvement is rare in HP, suggesting a systemic inflammatory involvement.

Cryobiopsy in the diagnosis of bronchiolitis: a retrospective analysis of twenty-three consecutive patients.

Bronchiolitis manifests as a variety of histological features that explain the complex clinical profiles and imaging aspects. In the period between January 2011 and June 2015, patients with a cryobiopsy diagnosis of bronchiolitis were retrospectively retrieved from the database of our institution. Clinical profiles, imaging features and histologic diagnoses were analysed to identify the role of cryobiopsy in the diagnostic process. Twenty-three patients with a multidisciplinary diagnosis of small airway disease were retrieved (14 females, 9 males; age range 31-74 years old; mean age 54.2 years old). The final MDT diagnoses were post-infectious bronchiolitis (n = 5), constrictive bronchiolitis (n = 3), DIPNECH (n = 1), idiopathic follicular bronchiolitis (n = 3), Sjogren's disease (n = 1), GLILD (n = 1), smoking-related interstitial lung disease (n = 6), sarcoid with granulomatous bronchiolar disorder (n = 1), and subacute hypersensitivity pneumonitis (n = 2). Complications reported after the cryobiopsy procedure consisted of two cases of pneumothorax soon after the biopsy (8.7%), which were successfully managed with the insertion of a chest tube. Transbronchial cryobiopsy represents a robust and mini-invasive method in the characterization of small airway diseases, allowing a low percentage of complications and good diagnostic confidence.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline.

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

High-resolution CT features distinguishing usual interstitial pneumonia pattern in chronic hypersensitivity pneumonitis from those with idiopathic pulmonary fibrosis.

PURPOSE: Radiologic diagnosis of chronic hypersensitivity pneumonitis (CHP) presenting a usual interstitial pneumonia (UIP) pattern is challenging. The aim of this study was to identify the high-resolution CT (HRCT) findings which are useful to discriminate CHP-UIP from idiopathic pulmonary fibrosis (IPF). MATERIALS AND METHODS: This study included 49 patients with well-established bird-related CHP-UIP, histologically confirmed, and 49 patients with IPF. Two groups of observers independently assessed HRCT, evaluated the extent of each abnormal HRCT finding. When their radiological diagnosis was CHP-UIP, they noted the HRCT findings inconsistent with IPF. RESULTS: Correct CT diagnoses were made in 79% of CHP-UIP and 53% of IPF. Although no apparent difference was seen in the extent of each HRCT finding, upper or mid-lung predominance, extensive ground-glass abnormality, and profuse micronodules were more frequently pointed out as inconsistent findings in CHP-UIP than IPF (p = 0.007, 0.010, 0.001, respectively). On regression analysis, profuse micronodules [OR 13.34 (2.85-62.37); p = 0.001] and upper or mid-lung predominance of findings [OR 2.86 (1.16-7.01); p = 0.022] remained as variables in the equation. CONCLUSION: In this cohort, some IPF cases were misdiagnosed as CHP-UIP. Profuse micronodules and upper or mid-lung predominance are important clues for the differentiation of CHP-UIP from IPF.

Clinical significance of self-reported cough intensity and frequency in patients with interstitial lung disease: a cross-sectional study.

BACKGROUND: The intensity and frequency of cough remain unclear in interstitial lung disease (ILD). The aim of this study was to evaluate the intensity and frequency of cough in idiopathic interstitial pneumonias (IIPs), connective tissue disease-associated interstitial lung disease (CTD-ILD), and chronic hypersensitivity pneumonia (CHP), and examine their associations with clinical indices. METHODS: In this cross-sectional study, the intensity and frequency of cough were evaluated using a 100-mm visual analogue scale. Scores on the Leicester Cough Questionnaire, chronic dyspnoea scale, and a frequency scale for symptoms of gastro-oesophageal reflux disease (FSSG) were collected. The correlations of cough intensity and frequency with potential predictor variables were tested using bivariate and multiple logistic regression analysis. RESULTS: The study included 70 patients with IIPs, 49 with CTD-ILD, and 10 with CHP. Patients with IIPs had the most severe cough intensity among the three patient groups. In patients with IIPs, both the intensity and frequency of cough were negatively associated with the diffusing capacity of the lung for carbon monoxide and positively with the Composite Physiologic Index (CPI). In CTD-ILD, both the intensity and frequency of cough were correlated with a higher FSSG score. In multivariate analysis of patients with ILD, IIPs and the FSSG score were independently associated with both components of cough, and CPI tended to be independently associated with cough frequency. Finally, we examined the features of the differences between cough intensity and frequency in all patients with ILD. Patients in whom cough frequency was predominant had a greater impairment of health status relative to other patients. CONCLUSIONS: Cough intensity was greater in IIPs than in other ILDs. Different clinical indices were associated with patient-reported cough intensity and frequency according to the subtype of ILD. Cough frequency was more strongly associated with health status than was cough intensity. These findings suggest that medical staff could manage patients with ILD by considering cough-related factors when assessing the intensity and frequency of cough.

Sertraline-induced hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a granulomatous, non-IgE-mediated hypersensitivity reaction of the alveoli and distal bronchioles presenting as an acute, subacute or chronic condition. It is most commonly associated with exposure to extrinsic allergens (eg, avian dust, mould and tobacco) and medications including antiarrhythmics (eg, amiodarone), cytotoxics (eg, methotrexate) and antiepileptics (eg, carbamazepine). Individuals diagnosed with this condition can present with severe hypoxia and respiratory failure. The fundamental principle of management is to remove the causative allergen. Evidence implicating selective serotonin reuptake inhibitors as a causative agent is limited, and this case report describes a rare clinical presentation of HP associated with sertraline, how it was diagnosed and subsequently treated. It is anticipated that raising awareness of this interaction will assist multidisciplinary teams, managing patients diagnosed with HP, to be more cognisant of sertraline as being an aetiological factor for this condition.

An Incidental Finding at Transplant Assessment: Case Report.

A 43-year-old woman with chronic hypersensitivity pneumonitis was referred for lung transplant assessment. An echocardiogram as part of her work-up revealed a large left atrial myxoma, presenting a conundrum on how best to manage her combined pathology. Because of the level of pulmonary disease, early intervention to remove the myxoma was not thought be viable without postoperative support. Use of extracorporeal membrane oxygenation to bridge patients for lung transplant is feasible, yet risks increased perioperative mortality. We present the first reported case of simultaneous cardiac myxoma removal and lung transplant.

Hypersensitivity pneumonia and HIV infection in occupational settings: a case report from northern Italy.

We describe a case of relapsing hypersensitivity pneumonitis (HP) manifesting as a reconstitution inflammatory syndrome (IRIS) in a HIV infected patient receiving antiretroviral therapy (HAART). The patient, who works as a farmer since the early 20s, was diagnosed with HP at age 23: after an initial steroid therapy, a long lasting clinical regression followed. At age 32, HIV positivity was diagnosed, with HAART starting only at age 38 (initially, lamivudine 300 mg/daily + zidovudine 300 mg b.i.d.). In the following 15 years, CD4+ count remained <500 cells/µL until therapy was shifted to ritonavir 100 mg b.i.d + fosamprenavir 700 mg b.i.d. A six-months long increase in the CD4+ count (>600 cells/µL) with undetectable viral load then followed. Eventually, the patient developed cough and slowly worsening dyspnoea. Laboratory exams (serum T cell lymphocyte count 83%, CD8+ 45-51%; serum IgG for M faeni=78 mg/L and P notatum >200 mg/L) and high-resolution computer tomography (HRCT) were compatible with relapsing HP. The working tasks were modified avoiding any contact with allergens, then achieving a 6 months long clinical regression. Detectable HIV load (62 copies/mL) was identified at follow-up, and emtricitabine 200 mg/tenofovir disoproxil fumarate 245 mg s.i.d. was added to HAART. Respiratory involvement newly relapsed. HAART was shifted to emtricitabine 200 mg/tenofovir disoproxil fumarate 245 mg s.i.d. and raltegravir 400 mg b.i.d. Within several weeks, signs and symptoms resolved almost completely (peripheral oxygen saturation >95%: CD4+ count remained >600 cells/µL with CD8+ count steadily <50% and CD4+/CD8+ ratio >55%).

[Hypersensitivity pneumonitis presenting as acute respiratory distress syndrome]. / Pneumopathie d'hypersensibilité révélée par un syndrome de détresse respiratoire aiguë.

INTRODUCTION: Hypersensitivity pneumonitis (HP) are typically subacute in their presentation and the diagnosis may be difficult. METHOD: We report a case of a hypersensitivity pneumonitis in a 27-years-old woman, caused by exposure to mould in an insalubrious mobile home. The initial presentation was with acute respiratory distress syndrome complicating RSV pneumonia, treated with ribavirin and corticosteroids in winter 2013-2014. The diagnosis of hypersensitivity pneumonitis was based on clinical and radiological relapse occurring during winter 2014-2015 with confirmed exposure to antigen with fungal sampling at home, respiratory deterioration with antigen rechallenge and a compatible chest CT-scan. CONCLUSION: The diagnosis of hypersensitivity pneumonitis should be considered in similar cases. Treatment is based mainly on removing exposure to the causative antigen.