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.

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.

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.

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.

The role of flexible bronchoscopy in the diagnostic pathway of children with unexplained peripheral eosinophilia.

BACKGROUND: Many possible underlying causes can be seen in children with unexplained peripheral eosinophilia (UPE) with suspected pulmonary involvement. Here, we aimed to demonstrate the clinical characteristics and diagnoses of children evaluated for UPE who underwent diagnostic bronchoscopy. METHODS: Thirty-one children who underwent diagnostic bronchoscopy for UPE between 2006-2018 were included. Demographic characteristics, bronchoscopy findings and final diagnosis, and treatments were evaluated. RESULTS: The median age at the time of diagnosis was 5 (0.25-17.5) years. The final diagnoses of 26 patients were as follows: immunodeficiency (n = 6); hyper-IgE syndromes (n = 4), DOCK8 deficiency + HES (idiopathic hypereosinophilic syndrome; n = 1), and severe combined immunodeficiency (n = 1), HES (n = 3), idiopathic chronic eosinophilic pneumonia (ICEP; n = 3), idiopathic pulmonary hemosiderosis (n = 1), B cell lymphoma (n = 1). In one child, an integrin α3 mutation + cytomegalovirus (CMV) pneumonia was detected. Congenital pneumonia was found in one patient, and parasitic infection in another. In two, eosinophilia was attributed to underlying asthma and atopy. In four, the underlying reasons could not be elucidated. Two children with HES and one with ICEP were lost to follow-up. There was no significant relationship between the peripheral eosinophil count at the time of diagnosis and the percentage of bronchoalveolar lavage eosinophils (BAL). Bronchoscopy contributed to the management of 14 (53.9%) patients. CONCLUSIONS: Bronchoscopy has potential diagnostic contribution in patients with UPE suspected of having pulmonary involvement. Numerous various underlying causes may be present in this patient group. There is no relation between peripheral eosinophil count and BAL eosinophil percentage.

Acute Eosinophilic Pneumonia after Combined Use of Conventional and Heat-Not-Burn Cigarettes: A Case Report.

Background: Acute eosinophilic pneumonia (AEP) is a rare acute respiratory disease accompanied by fever, shortness of breath, and cough. Although the pathogenesis of the disease is not yet established, the patient's condition improves with a rapid therapeutic response to systemic corticosteroids. Conventional cigarettes or heat-not-burn cigarettes are the most common cause of AEP among young people. Case Presentation: A 22-year-old woman with dyspnea, cough, and fever did not improve after visiting the local medical center and was admitted to the emergency room. The patient denied having any recent travel history or insect bites. She was treated with appropriate antibiotics according to the community acquired pneumonia, but there was no improvement. Chest radiography showed bilateral patches of pulmonary infiltration, and chest computed tomography revealed bilateral multifocal patchy consolidations with multiple small nodular ground-glass opacities and interlobular septal thickening. The bronchoalveolar lavage result was dominantly eosinophilic. The patient's condition improved rapidly after the use of intravenous methylprednisolone and then a change to oral methylprednisolone. Finally, the patient was hospitalized for 9 days, and the duration of use of methylprednisolone including outpatient visits was 14 days. Results: The early treatment of AEP yields a good prognosis, but since the symptoms of AEP are similar to those of infectious diseases such as community-acquired pneumonia, physicians should be meticulous in differentiating AEP from other diseases. Conclusions: Since AEP shows a good response to steroids, early detection using an appropriate diagnostic method is recommended. In addition, there should be strong education against smoking in any form.

[Clinical analysis of chronic eosinophilic pneumonia in 9 cases].

Objective: To investigate the clinical features, treatment and prognosis of chronic eosinophilic pneumonia. Methods: Nine patients with chronic eosinophilic pneumonia diagnosed in Shandong Provincial Qianfoshan Hospital from January 2014 to December 2020 were enrolled and followed up. The data of clinically proven chronic eosinophilic pneumonia were reviewed. Results: The 9 cases included one male and eight females, aged from 16 to 71 years (median 47 years). Among them, 5 cases were complicated with asthma, 1 case was complicated with allergic rhinitis, and 1 case had an allergic history of pollen. All the patients had cough, expectoration, chest tightness and wheezing, and a few had fatigue (3/9), fever (1/9) and chest pain (1/9). Single or multiple patchy high-density shadows (9/9), mediastinal lymphadenopathy (7/9), air bronchogram (2/9), and reticular shadow (1/9) were observed in chest CT. Peripheral eosinophils (EOS) and serum total IgE increased to varying degrees in the 9 patients. Meanwhile, the bronchoscopy of 5 cases showed elevated percentage of eosinophils in alveolar lavage fluid, and the lung biopsy of remaining 4 cases showed EOS infiltration in lung alveolar and interstitium. After receiving glucocorticoid therapy for 0.5 to 1 month, the clinical symptoms of all 9 patients had been improved and lung lesions on CT scans had been obviously absorbed. Four cases relapsed during follow-up. Conclusions: For patients especially women who have a history of allergy, elevated blood eosinophils and serum total IgE with pulmonary high-density shadow or consolidation, chronic eosinophilic pneumonia should be considered, and bronchoscopy or percutaneous lung biopsy is indicated for a definite diagnosis. Glucocorticoid therapy is effective, but the rate of recurrence is high.

Chronic Eosinophilic Pneumonia Masquerading as a Lung Mass.

Lung masses are becoming more common, and although most are tumors, benign or malignant, some are not solid masses. Many pathologies can present as lung nodules, including lung cancers, hamartomas, lung abscesses, granulomas, and eosinophilic pneumonia, to name a few. A 40-year-old woman with a long history of smoking presented with cough and left-sided chest pain. After multiple imaging studies, she was thought to have a lung malignancy; however, multiple biopsies proved this was not the case. The histology reports of 3 to 4 biopsies at separate times indicated chronic inflammation ongoing in the lungs without any cancer cells present. She was treated for chronic eosinophilic pneumonia with a resolution of symptoms. The purpose of this case report is to discuss a case that was initially thought to be a lung mass but found to be chronic eosinophilic pneumonia manifesting as a lung mass.

Clinical characteristics of patients with chronic eosinophilic pneumonia in a Chinese tertiary-care hospital: A 6-year retrospective study.

INTRODUCTION: Chronic eosinophilic pneumonia (CEP) is a rare disease with unknown etiology. Due to lack of specificity of CEP symptoms, clinicians are not experienced in establishing its diagnosis. OBJECTIVES: To summarize the clinical data of CEP patients to improve the understanding of CEP and reduce misdiagnosis. METHODS: Data of patients pathologically diagnosed with CEP in the PLA General Hospital between May 2013 and May 2019 were collected, and clinical manifestations, imaging characteristics, pathological features, and treatment were retrospectively analyzed. RESULTS: Twenty patients, including 6 males and 14 females, were diagnosed with CEP. The average age was 47.0 ± 10.2 years. The main clinical manifestations were cough and dyspnea. The average duration of CEP was 15.5 ± 11.5 months. The average proportion of eosinophils in the peripheral blood was 18.9 ± 17.8%, and the average proportion of eosinophils in the bronchoalveolar lavage fluid was 41.5 ± 19.4%. The main imaging features were patchy shadows and consolidation shadows. The most common manifestations on bronchoscopic examination were congestion and edema of the bronchial mucosa. Two patients had granular protrusions of the endotracheal membrane. Histological examination indicated infiltration of numerous eosinophils. All patients improved after prednisone therapy. CONCLUSION: CEP onset is insidious, and clinical manifestations lack specificity. Typical imaging features are peripheral and subpleural distribution of lung infiltrates. Some patients have a normal proportion of eosinophils in the peripheral blood, but most have an increased number of eosinophils in the BALF, which contributes to CEP diagnosis. A biopsy is necessary when differential diagnosis is difficult. A systemic glucocorticoid is effective.