Young lady with hypersensitivity pneumonitis post fumigation

Introduction: The hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a pulmonary disease that occurs in response to inhaled organic material,or even of simple chemicals, organic and inorganic with symptoms of cough,fever,chills,wheezing and shortness of breath.The prevalence and incidence of HP appear to vary considerably depending upon case definitions, intensity of exposure to inciting antigens, season, geographical conditions,proximity to certain industries, and host risk factors.It has been divided into three forms,acute,subacute and chronic depending on onset of symptoms,exposure of inciting agent and radiological and histopathological findings and choice of treatment. Case: 45 year old female,hypertensive.Admitted with complain of shortness of breath,cough for 2 weeks and fever for 3 days.Symptoms started after fumigation.No prior history of allergies,pets at home.On examination there O2 sats=95% on RA.CXR showed bilateral peribronchial infiltrates.HRCT done which showed randomly distributed patchy areas of consolidation and ground glass opacification predominantly in bilateral lower lobes with preserved lung volume.With the suspicion of hypersensitivity pneumonitis she was started on oral prednisolone and later discharged home.Patient was noncomplaint to prednisolone.She got re-admitted after few months with worsening symtoms.Her RA sats were 85%.However CXR showed no new change.Bronchoscopy done which showed normal airways,BAL was negative for any microbiological etiology.ANA profile was inconclusive.She was treated with prednisolone.CT chest with contrast showed improvement in patchy consolidation and ground glass opacification.PFT showed nonspecific airway disease.To get a diagnosis,surgical lung biopsy was done,tissue afb and fungus came out to be negative.Histopathology revealed heterogenicity with relatively preserved lung parenchyma with interstitial expansion due to fibrosis,acute on chronic inflammatory cells along with plasma cells and some evidence of honey combing.subpleural fibrosis seen.Patient was continued on steroids and clinical improvement seen,long term home oxygen therapy initiated along with pulmonary rehabilitation.Patient was later discharged to the outpatient service. Conclusion: Hypersensitivity pneumonitis (extrinsic allergic alveolitis) is a syndrome caused by repeated inhalation of specific antigens from occupational or environmental exposure in sensitized individuals.Continous exposure to the anigen can led to fibrosis which can be irreversible and resistant to any treatment. Knowledge of HP evolution is essential, particularly in the professional level as continuous exposure can lead to morbidity as in case of our patient