A case of naltrexone-induced acute eosinophilic pneumonia.

Acute eosinophilic pneumonia (AEP) is a rare cause of acute respiratory failure. Clinical presentations can range from dyspnoea, fever and cough, to rapidly progressive and potentially fulminant respiratory failure. While its exact cause is often unknown, associations with inhalational injuries and exposures to new medications have been described.We report a case of a middle-aged, non-smoking man with a history of alcohol use disorder. He presented with 4 days of shortness of breath that started hours after taking injectable naltrexone (Vivitrol). The patient had rapidly worsening hypoxaemia, necessitating emergent bronchoscopy with transbronchial biopsies and bronchoalveolar lavage which showed 66% eosinophils. The patient was intubated for the procedure and unable to get extubated due to worsening hypoxaemic respiratory failure with high fractional inspired oxygen requirements. Chest radiograph showed worsening lung infiltrates and with a high index of suspicion for AEP, he was started empirically on methylprednisolone. He had rapid improvement in his respiratory status and was extubated on day 5 of admission then discharged on day 8. Histopathological examination confirmed acute/subacute eosinophilic pneumonia. A 3-week post-discharge follow-up chest radiograph confirmed the full resolution of pulmonary infiltrates.Naltrexone-induced AEP is rare, with only six other cases reported in the literature. Careful history taking and prompt evaluation for AEP are important given the potential for rapid progression to acute hypoxic respiratory failure and the excellent response to steroid treatment.

Eosinophilic pulmonary disease with ulcerative colitis: A case report.

RATIONALE: Eosinophilic pulmonary disease (EPD) is a general term for a large group of diseases with complex etiology. Ulcerative colitis is an inflammatory bowel disease (IBD). Patients with IBD may have pulmonary involvement. We herein present a case of ulcerative colitis complicated with EPD. PATIENT CONCERNS: A 34-year-old woman with ulcerative colitis presented with dry cough. She had peripheral eosinophilia and apical ground glass opacities on CT (computed tomography) of her chest. Antibiotic treatment was ineffective. DIAGNOSES: Lung biopsy revealed eosinophil infiltration in the alveolar space and interstitial space, so EPD was considered. INTERVENTIONS: After oral administration of prednisone, the lung shadow on CT disappeared when the cough symptoms resolved. However, the symptoms recurred after drug withdrawal, and the lung shadow reappeared on imaging. The cough symptoms and lung shadow disappeared after oral prednisone was given again. Prednisone was slowly discontinued after 6 months of treatment. OUTCOMES: The patient stopped prednisone for half a year. No recurrence or abnormal CT findings were detected during the half-year follow-up. LESSONS: The clinical manifestations of EPD are atypical, laboratory and imaging findings are not specific, and it is difficult to make a definite diagnosis before lung biopsy. The diagnosis depends on pathological examination. Glucocorticoid treatment is effective, but some patients may relapse after drug withdrawal. Active follow-up after glucocorticoid treatment is very important for identifying disease recurrence. Patients with IBD are relatively prone to developing EPD. The etiology of EPD is complex. In clinical practice, we need to make a diagnosis and differential diagnosis to clarify its etiology.

Daptomycin-induced eosinophilic pneumonia.

ABSTRACT: Daptomycin-induced eosinophilic pneumonia (DIEP) is a rare complication of daptomycin use. Manifestations most commonly include fever, hypoxia, dyspnea, cough, eosinophilia, and lung changes on radiographs and CT. Patients typically have had recent daptomycin exposure and develop fever, dyspnea, infiltrates on chest radiograph, more than 25% eosinophils on bronchoalveolar lavage, and improvement of symptoms after withdrawal of daptomycin. Treatment includes discontinuation of daptomycin, corticosteroids, and supportive measures such as supplemental oxygen. Clinicians should have a high index of suspicion for DIEP in patients who develop new onset of pulmonary and systemic signs and symptoms after initiation of daptomycin.

Critical deterioration of chronic eosinophilic pneumonia during pregnancy.

Chronic eosinophilic pneumonia (CEP) is a rare, idiopathic interstitial lung disease characterised by the accumulation of eosinophils in the pulmonary interstitia and alveoli. Patients with CEP respond well to systemic corticosteroid therapy and infrequently progress to end-stage lung disease. We report a case of a woman in her 40s with previously stable, steroid-responsive CEP who experienced a critical deterioration of her CEP at 25 weeks of gestation during her third pregnancy. The patient was admitted to the intensive care unit due to respiratory failure requiring intubation and mechanical ventilation. Follow-up investigation revealed advanced fibrotic lung disease requiring long-term oxygen therapy and referral for double lung transplantation. While CEP infrequently advances to permanent parenchymal damage, this case demonstrates the potential for severe exacerbations in the setting of pregnancy and highlights pregnancy as a potential risk factor for disease progression, reinforcing the need for further research to define optimal monitoring and treatment strategies.

Case Report: Allergic Bronchopulmonary Aspergillosis and Tropical Pulmonary Eosinophilia Co-Occurrence Masquerading as Refractory Allergic Bronchopulmonary Aspergillosis.

Pulmonary infiltrates with eosinophilia are a heterogeneous group of disorders that are characterized by pulmonary infiltrates on chest radiograph and elevated levels of eosinophils in the peripheral blood. Among patients with these disorders, reports of either allergic bronchopulmonary aspergillosis (ABPA) or tropical pulmonary eosinophilia (TPE) are common. However, the simultaneous occurrence of ABPA and TPE is not often reported. We present the case of a young man with a history of asthma who was diagnosed with ABPA and TPE. Initially, the patient exhibited a partial response to treatment of ABPA, but persistent symptoms and eosinophilia led to suspicion and subsequent diagnosis of TPE. With implementation of antifilarials and steroids, the patient experienced satisfactory clinical and serological improvements. This case underscores the importance of considering multiple diagnoses in patients with overlapping symptoms and highlights the need for comprehensive management strategies in complex lung diseases.

Dupilumab suppresses relapsing chronic eosinophilic pneumonia with severe asthma.

Dupilumab-induced hypereosinophilia is mediated by blockade of the IL-4/IL-13 pathway, which reduces eosinophil migration from peripheral blood. The increase in peripheral blood eosinophils may lead to chronic eosinophilic pneumonia (CEP) and/or eosinophilic granulomatosis with polyangiitis, but a direct causal connection between dupilumab and eosinophilic lung diseases has not been established. A 33-year-old Japanese woman with bronchial asthma since age three was treated with fluticasone propionate plus salmeterol twice daily after several asthma exacerbations at age 17. Her course was complicated by CEP at age 33 which resolved without the need for systemic steroids. However, in the four months following resolution of her CEP, the patient had three asthma exacerbations, and a recurrence of CEP, with blood leukocytes of 8500/µL, of which 25.0% were eosinophils. She was treated with prednisolone 50 mg/day, but she could not continue this dose due to the onset of myalgia. Then she had relapsing CEP twice within three months. She was treated with prednisolone 15 mg/day for CEP, but she had persistent asthma for more than one month; dupilumab was added at 600 mg, followed by 300 mg every two weeks. In the first month of treatment with dupilumab, the patient's asthma symptoms resolved completely, and she had only one relapse of CEP. In 12 months of follow-up, she had neither an asthma exacerbation nor another relapse of CEP. Dupilumab may be a promising treatment for patients with refractory asthma complicated by recurring CEP and undesirable steroid side effects.

Acute Eosinophilic Pneumonia Masquerading as a Lung Abscess.

BACKGROUND: Acute Eosinophilic Pneumonia (AEP) is a rare form of non-infectious pneumonia that is easily missed and misdiagnosed because of its atypical clinical symptoms and misleading laboratory and imaging studies. METHODS: By reporting a case of an initial diagnosis of lung abscess, which was treated with antibiotics and then CT suggesting that the lesion continued to worsen, it was eventually confirmed to be AEP by lung biopsy, A joint literature analysis was conducted to improve clinicians' understanding of the diagnosis and treatment of AEP. RESULTS: Initially, because of the atypical ancillary findings, we thought the disease was a lung abscess, which was eventually confirmed by pathology as AEP. CONCLUSIONS: The presence of AEP needs to be considered when various laboratory findings point to infectious dis-ease, but anti-infection is not effective. Diagnosis can be confirmed by bronchoalveolar lavage and lung tissue biopsy. Prompt treatment can provide rapid relief and reduce the risk of patient death.

Vaping Associated Acute Eosinophilic Pneumonia: A Clinical and Radiologic Mimicker of COVID-19.

Acute eosinophilic pneumonia (AEP) is a rare cause of respiratory failure. It is primarily a disease of smokers, either a new smoker or an existing one with a recent increase in cigarette consumption. Other risk factors include toxic gas exposure, inhalational illicit drugs, and smoking marijuana. AEP has also been reported in patients with e-cigarette or vaping associated lung injury (EVALI). We present the case of a 20-year-old male who presented to the hospital with acute respiratory failure. The patient has been vaping heavily for the past three months and started smoking three days before presenting to the emergency department. He was hypertensive, tachycardic, tachypneic, and required high-flow nasal cannula to maintain SpO2 > 92%. His condition deteriorated in the first 24 hours following hospitalization requiring noninvasive positive pressure ventilation. Bronchoalveolar lavage revealed an eosinophil count of 36%. Bronchoalveolar lavage (BAL) cytology revealed lipid-laden macrophages. He was diagnosed with AEP due to EVALI, and the patient was treated with high dose corticosteroid with subsequent improvement. Before the bronchoscopic evaluation, the clinical and radiologic findings were consistent with COVID-19, and the patient was tested twice for SARS-CoV-2 PCR. In the appropriate clinical setting, AEP should be considered in the differential diagnoses of community-acquired pneumonia, acute respiratory distress syndrome (ARDS), and COVID-19, especially in this pandemic era.

Achieving clinical outcomes with benralizumab in severe eosinophilic asthma patients in a real-world setting: orbe II study.

BACKGROUND: The ORBE II study aimed to describe the characteristics and clinical outcomes of adult patients with severe eosinophilic asthma (SEA) treated with benralizumab in a real-world setting in Spain. METHODS: ORBE II (NCT04648839) was an observational, retrospective cohort study in adult SEA patients who had been prescribed benralizumab. Demographic and clinical data of 204 SEA patients were collected 12 months prior to benralizumab initiation (baseline) and at follow-up. Exacerbation rate, asthma symptoms, maintenance oral corticosteroid (OCS) use and lung function were evaluated, among other variables. RESULTS: A total of 204 SEA patients were evaluated. Mean (standard deviation, SD) age of the study population was 56.4 (12.4) years, 62.3% were women and mean (SD) duration of asthma was 15.1 (12.7) years. Median (Q1-Q3) follow-up duration was 19.5 (14.2-24.2) months. At baseline, 72.6% of the overall population (OP) presented blood eosinophil counts ≥ 300 cells/µL; 36.8% had comorbid chronic rhinosinusitis with nasal polyps (CRSwNP); 84.8% reported at least one severe exacerbation, and 29.1% were OCS-dependent. At 1 year of follow-up, patients receiving benralizumab treatment had a 85.6% mean reduction in exacerbations from baseline, and 81.4% of patients achieved zero exacerbations. We also found a clinically relevant mean (SD) increase in pre-bronchodilator (BD) FEV1 of 331 (413) mL, with 66.7% of patients achieving a pre-BD FEV1 increase ≥ 100 mL, and 46.3% of patients achieving a pre-BD FEV1 ≥ 80% of predicted. Regarding symptom control, 73.8% of the OP obtained an ACT score ≥ 20 points. After 1 year of follow-up, mean reduction in the daily OCS dose was 70.5%, and complete OCS withdrawal was achieved by 52.8% of the OCS-dependent patients. Almost half (43.7%) of the OP on benralizumab met all four criteria for clinical remission. Patients with concomitant CRSwNP obtained similar or enhanced outcomes. CONCLUSIONS: These data support the real-world benefits of benralizumab in SEA patients, and particularly in those with concomitant CRSwNP. TRIAL REGISTRATION: NCT04648839.

A rare case of acute eosinophilic pneumonia induced by vaping-associated lung injury: a case report.

BACKGROUND: Acute eosinophilic pneumonia (AEP) is well-known as one of the primary eosinophilic pulmonary diseases of unknown etiology. It's defined as a febrile illness along with acute onset respiratory failure that is commonly misdiagnosed at the initial presentation as infectious pneumonia. Despite the fact that AEP sometimes classified as idiopathic as no exact cause can be identified in most cases, it has been suggested recently to be linked with electronic cigarette or vaping products and associated with electronic cigarette or vaping associated lung injury (EVALI). Therefore, history of recent tobacco smoking or vaping exposure along with peripheral eosinophilia are crucial clinical findings suggestive of AEP. CASE PRESENTATION: A previously healthy 17-year-old female presented to the Emergency Room with one day history of progressively worsening shortness of breath accompanied by left sided pleuritic chest pain and fever. She wasn't taking any medications, denied traditional cigarette smoking, exposure to pulmonary irritants, recent travel and had no history of close contact with sick patient. She recently started vaping 20 days prior to the presentation. Initially, she was admitted with a presumptive diagnosis of atypical pneumonia but was found to have AEP due to a recent vaping exposure. CONCLUSION: Vaping is a well-known health hazard that has become a growing trend among adolescents and have been promoted as a safe and effective alternative to traditional cigarettes. The etiology of AEP remains unclear, but many studies suggest a possible link with recent tobacco smoking or vaping. A key challenge for this clinical entity is to reach the diagnosis after excluding all other pulmonary eosinophilia causes, and it has an excellent prognosis if diagnosed early and treated appropriately.

A case of hypocomplementemic urticarial vasculitis syndrome complicated by eosinophilic pneumonia: a case report and review of the literature.

The primary symptom of urticarial vasculitis (UV), which is a histopathological leukocytoclastic vasculitis disease, is an eruption that resembles urticaria. Other organs may also experience accompanying symptoms. Lung lesions with UV are mostly obstructive pulmonary disease with smoking. However, the coexistence of eosinophilic pneumonia (EP) and complicated UV remains unclear. We report a man in his 70s with chronic obstructive pulmonary disease who attended our department with ring-shaped erythema, marginal edema, and pigmentation. Additionally, a skin histological analysis showed nuclear dust and perivascular neutrophil infiltration, while a blood sample showed a decrease in C3 and C1q concentrations. Administration of prednisone temporarily improved the eruption. However, he developed a cough and a new UV eruption 1 year later. Computed tomography revealed infiltration in the right upper lobe of the lungs, and a blood sample showed a high eosinophil count. He was finally diagnosed with hypocomplementemic urticarial vasculitis syndrome and idiopathic chronic EP. A previous study showed that serum C1q concentrations in patients with EP were lower when this disease was active. Whether a decline in C1q concentrations can cause EP is unclear. However, our case is unique owing to the co-onset of EP with low complement concentrations and recurrence of UV.

Acute eosinophilic pneumonia-like syndrome post-initiation of vortioxetine.

A man in his mid-30s presented to the emergency department with a 1-week history of fatigue, loss of appetite, fever and productive (yellow) cough. This progressed to requiring admission to intensive care needing a oxygen therapy via high-flow nasal cannula for acute hypoxaemic respiratory failure. He had recently started vortioxetine for major depressive disorder, and his acute symptoms correlated with an increase in the dose of vortioxetine. For more than 20 years, rare but consistent reports of serotonergic medications have been implicated in eosinophilic pulmonary conditions. During this same period, serotonergic medications have become a mainstay solution for a wide range of depressive symptoms and disorders. This is the first report of an eosinophilic pneumonia-like syndrome occurring while consuming the novel serotonergic medication vortioxetine.

Long-term effectiveness of benralizumab in severe eosinophilic asthma patients treated for 96-weeks: data from the ANANKE study.

BACKGROUND: The efficacy of benralizumab has been broadly demonstrated in severe eosinophilic asthma (SEA), but only few real-life studies evaluated its long-term effects. Here we present novel data from the ANANKE study in which a large cohort of SEA patients was treated for up to 96 weeks. METHODS: ANANKE (NCT04272463) is an observational retrospective Italian study investigating the key characteristics of SEA patients (collected during the 12 months prior to benralizumab initiation) and the clinical outcomes during benralizumab treatment (annual exacerbation rate [AER], lung function, asthma control, OCS use, healthcare resource utilization). A post hoc analysis was also conducted in groups of patients based on history of previous biologic therapy (bio-experienced versus naïve patients). Analyses were descriptive only. RESULTS: Before benralizumab initiation, evaluable SEA patients (N = 162, 61.1% females, mean age 56.0 ± 12.7) showed a median blood eosinophil count (BEC) of 600 cells/mm3 (IQR: 430-890). Patients experienced frequent exacerbations (annualized exacerbation rate [AER]: 4.10, severe AER: 0.98), with impaired lung function and poor asthma control (median ACT score: 14) despite 25.3% reported oral corticosteroid (OCS) use. Nasal polyposis was present in 53.1% patients; 47.5% patients were atopic. After 96 weeks since the start of benralizumab, nearly 90% patients were still on treatment; benralizumab dramatically decreased exacerbations (AER: - 94.9%; severe AER: - 96.9%), improved respiratory parameters (median increase in pre-bronchodilator forced expiratory volume [pre-BD FEV1]: + 400 mL) and asthma control (median ACT score: 23) while eliminating OCS in 60% patients. Importantly, benralizumab effects were either maintained or progressively improved over time, accompanied by a nearly complete depletion of BEC. Benralizumab reduced AER both in naïve (any AER: - 95.9%; severe AER: - 97.5%) and bio-experienced patients (any AER: - 92.4%; severe AER: - 94.0%). CONCLUSIONS: Profound and sustained improvements in all asthma outcomes were observed with benralizumab. The correct identification of patients' eosinophilic-driven asthma phenotype was essential to ensure the achievement of such remarkable results. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04272463.

Respiratory virus infections of the lower respiratory tract elevate bronchoalveolar lavage eosinophil fraction: a clinical retrospective study and case review.

BACKGROUND: Eosinophilic airway inflammation caused by respiratory virus infection has been demonstrated in basic research; however, clinical investigations are lacking. To clarify the extent to which respiratory virus infection induces airway eosinophilic inflammation, we reviewed the results of bronchoalveolar lavage (BAL) and respiratory virus testing performed at our hospital. METHODS: Among the BAL procedures performed at the University of the Ryukyu Hospital from August 2012 to September 2016, we collected cases of acute respiratory disease in which multiplex polymerase chain reaction (PCR) was used to search for respiratory viruses. The effect of respiratory virus detection on BAL eosinophil fraction was analyzed using statistical analysis. A case study was conducted on respiratory virus detection, which showed an elevated BAL eosinophil fraction. RESULTS: A total of 95 cases were included in this study, of which 17 were PCR-positive. The most common respiratory virus detected was parainfluenza virus (eight cases). The PCR-positive group showed a higher BAL eosinophil fraction than the PCR-negative group (p = 0.030), and more cases had a BAL eosinophil fraction > 3% (p = 0.017). Multivariate analysis revealed that being PCR-positive was significantly associated with BAL eosinophil fraction > 1% and > 3%. There were nine PCR-positive cases with a BAL eosinophil fraction > 1%, of which two cases with parainfluenza virus infection had a marked elevation of BAL eosinophil fraction and were diagnosed with eosinophilic pneumonia. CONCLUSIONS: Cases of viral infection of the lower respiratory tract showed an elevated BAL eosinophil fraction. The increase in eosinophil fraction due to respiratory virus infection was generally mild, whereas some cases showed marked elevation and were diagnosed with eosinophilic pneumonia. Respiratory virus infection is not a rare cause of elevated BAL eosinophil fraction and should be listed as a differential disease in the practice of eosinophilic pneumonia.

Validity of diagnoses of respiratory diseases recorded in a Japanese administrative database.

BACKGROUND: Validating the information recorded in administrative databases is essential. However, no study has comprehensively validated the accuracy of Japanese Diagnosis Procedure Combination (DPC) data on various respiratory diseases. Therefore, this study aimed to evaluate the validity of diagnoses of respiratory diseases in the DPC database. METHODS: We conducted chart reviews of 400 patients hospitalized in the departments of respiratory medicine in two acute-care hospitals in Tokyo, between April 1, 2019 and March 31, 2021, and used them as reference standards. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DPC data on 25 respiratory diseases were determined. RESULTS: Sensitivity ranged from 22.2% (aspiration pneumonia) to 100% (chronic eosinophilic pneumonia and malignant pleural mesothelioma) and was <50% for eight diseases, while specificity was >90% for all diseases. PPV ranged from 40.0% (aspiration pneumonia) to 100% (coronavirus disease 2019, bronchiectasis, chronic eosinophilic pneumonia, pulmonary hypertension, squamous cell carcinoma, small cell carcinoma, lung cancer of other histological types, and malignant pleural mesothelioma) and was >80% for 16 diseases. Except for chronic obstructive pulmonary disease (82.9%) and interstitial pneumonia (other than idiopathic pulmonary fibrosis) (85.4%), NPV was >90% for all diseases. These validity indices were similar in both hospitals. CONCLUSIONS: The validity of diagnoses of respiratory diseases in the DPC database was high in general, thereby providing an important basis for future studies.

Evaluation of the Clinical Features and Laboratory Data of Patients with Severe Eosinophilic Asthma Classified as Super-Responders, Partial Responders, or Nonresponders to Mepolizumab Treatment: A Real-Life Study.

INTRODUCTION: Mepolizumab is a treatment option in patients with severe eosinophilic asthma, which inhibits interleukin-5. The aim of this study was to evaluate the clinical features and laboratory data of patients with severe eosinophilic asthma who were classified as super-responders, partial responders, or nonresponders to mepolizumab treatment. METHODS: In this retrospective real-life study, the clinical features and laboratory data were compared between groups of patients with severe eosinophilic asthma who were classified as super-responders, partial responders, or nonresponders to mepolizumab treatment. RESULTS: Evaluation was made of a total of 55 patients, comprising 17 (30.9%) males and 38 (69.1%) females with a mean age of 51.28 ± 14.32 years. All the patients were receiving mepolizumab treatment for severe eosinophilic asthma, with 17 (30.9%) patients evaluated as super-responders, 26 (47.3%) as partial responders, and 12 (21.8%) as nonresponders. After mepolizumab treatment, there was a statistically significant decrease in asthma exacerbations, the number of oral corticosteroids (OCSs) used, the rate of hospitalization due to asthma attacks, and the eosinophil count (cells/µL) (p < 0.001, p < 0.001, p < 0.001, and <0.001, respectively). A statistically significant increase was determined in the forced expiratory volume in 1 s (FEV1) value (p = 0.010) and asthma control test (ACT) score (p < 0.001) after mepolizumab treatment. The baseline eosinophil count, eosinophil/lymphocyte ratio and FEV1 (%) values were significantly higher in the super-responder and partial responder groups (p < 0.001, p = 0.002, and p = 0.002, respectively). The baseline ACT score and the rate of chronic sinusitis with nasal polyps were significantly higher in the partial responder group (p = 0.004, p = 0.015, respectively). The rate of regular OCS use before mepolizumab treatment was significantly higher in the nonresponder group (p = 0.049). As a result of the receiver operating characteristics curve analysis, the blood eosinophil count (area under the curve [AUC]: 0.967, p < 0.001), eosinophil/lymphocyte ratio (AUC: 0.921, p < 0.001), and FEV1 (%) (AUC: 0.828, p = 0.002) were found to have diagnostic value in predicting the response to mepolizumab treatment in patients with severe eosinophilic asthma. CONCLUSION: Baseline eosinophil count, eosinophil/lymphocyte ratio, and FEV1 (%) were found to be important predictors of response to mepolizumab treatment. Further studies are needed to define the characterization of mepolizumab responders in the real world.

A case of chronic eosinophilic pneumonia associated with rheumatoid arthritis in glucocorticoid-free remission with JAK inhibitor: A case report.

RATIONALE: Chronic eosinophilic pneumonia (CEP) presents eosinophil infiltrations in the lung due to allergic reactions. Most CEP patients continue to take glucocorticoids, and their prolonged use induces various side effects. In this case report, based on the efficacy of baricitinib in patients with rheumatoid arthritis (RA) and CEP, we aimed to show that the administration of Janus kinase (JAK) inhibitors, when RA is complicated by an allergic disease, can stabilize the disease state and help avoid the adverse effects of long-term systemic glucocorticoid administration. PATIENTS CONCERNS: A 56-year-old woman developed RA at the age of 19 years. Treatment of the arthritis was initiated, but the joint destruction had progressed. At the age of 42, she developed eosinophilic pneumonia, which was relieved by glucocorticoid therapy. Since then, maintenance therapy has been continued with the diagnosis of CEP. She was treated with concomitant tacrolimus for persistent arthritis, and the prednisolone (PSL) dose was reduced to 3 mg/day after 10 years. However, around this time, an increase in peripheral blood eosinophil counts and respiratory symptoms was observed. DIAGNOSIS: The peripheral blood eosinophil count was 4000/µL and computed tomography revealed multiple ground-glass opacities in the peripheral lung fields. As interstitial pneumonia due to infection or other causes was ruled out, CEP relapse was diagnosed. INTERVENTIONS: Pneumonia rapidly recovered when the PSL dose was increased to 15 mg/day, and asymptomatic eosinophilic infiltrates reappeared in the lung field along with a relapse of arthritis when the PSL dose was reduced to 5 mg/day. Concomitant use of methotrexate and baricitinib has been introduced to suppress allergic reactions to pneumonia. OUTCOMES: After starting combination therapy with baricitinib and methotrexate, both arthritis and eosinophilia improved, and glucocorticoid-free remission was achieved. LESSONS: Recently, inhibition of IL-5 signaling via JAK2 has been reported to be effective in bronchial asthma and atopic dermatitis. Although complications of RA and CEP are not common, the actions of baricitinib are useful not only in arthritis but also in allergic diseases. The efficacy of some JAK inhibitors should be actively tested in patients with RA and these complications.