Severe eosinophilia in children: a diagnostic dilemma

Pediatric Eosinophilia: A Review and Multiyear Investigation into Etiologies

OBJECTIVES

To identify the etiology of peripheral eosinophilia in a large pediatric population and to develop a diagnostic algorithm to help guide diagnosis and management of peripheral eosinophilia in the outpatient pediatric population.

STUDY DESIGN

We performed a retrospective chart review of children presenting to Texas Children's Hospital in Houston with peripheral eosinophilia between January 1, 2011 and December 31, 2019. Eosinophilia was classified as mild (absolute eosinophil count [AEC] >500 and <1500 cells/μL), moderate (AEC >1500 and <4500 cells/μL), or severe (AEC >4500 cells/μL). Demographic information and diagnostic workup data were collected.

RESULTS

A total of 771 patients aged <18 years were evaluated. The most common cause of eosinophilia was allergy (n = 357; 46%), with atopy (n = 296) and drug reaction (n = 54) the most common subcauses. This was followed by unknown etiology (n = 274; 36%), infectious causes (n = 72; 9%), and eosinophilic disorders (n = 47; 6%). Many patients with an unknown cause (n = 202; 74%) had limited or no follow-up testing.

CONCLUSIONS

More information on the etiology of pediatric eosinophilia and workup data could help identify the causes. This study provides important information on the evaluation of eosinophilia in the US pediatric population, including a diagnostic algorithm to guide primary care pediatricians.

Distinguishment of parasite-infected children from pediatric inpatients with both eosinophilia and effusion

Patients with both serous effusion and eosinophilia are rarely reported and geographically distributed; their early diagnosis is difficult.According to the ultimate diagnosis, patients (≤14 years) in West China Second hospital with serous effusion and eosinophilia were divided into two groups including a parasitic group and a non-parasitic group. Clinical data were collected and analyzed between the two groups. Subsequently, significant measurement indicators were evaluated by receiver operating characteristic (ROC) curve to explore the optimal cut-off points for the most appropriate sensitivity and specificity.A total of 884 patients were diagnosed with serous effusion and 61 of them displayed co-morbidity with eosinophilia during enrolled time. Among 61 patients, 34 patients had parasitic infection and 27 had non-parasitic diseases. There were statistical difference in effusion position, the levels of white blood cell count (WBC), eosinophil (EOS), EOS%, C-reactive protein (CRP) between parasitic group and non-parasitic group. ROC curve demonstrated that the areas under the curve of EOS count and EOS% were >80%, and the corresponding optimal cut-off values were 1.71 × 10/L and 25.6% for distinguishing between parasitic and non-parasitic infections in our patients.This study provided a quantified index for potentially quick and convenient indicators of pediatric patients presenting with both eosinophilia and effusion. Eosinophils were helpful to improve the initial diagnosis with awareness of parasitic diseases. For the cases with EOS > 1.71 × 10/L or EOS% > 25.6%, parasitic infection should be considered and serological tests are recommended in our region.

Pediatric Hypereosinophilia: Characteristics, Clinical Manifestations, and Diagnoses

BACKGROUND

Eosinophilia is associated with various conditions, including allergic, infectious, and neoplastic disorders. The diagnostic differential is broad, and data on hypereosinophilia in pediatric patients are limited.

OBJECTIVE

The objectives of this study were to identify cases of hypereosinophilia in a tertiary pediatric medical center, determine clinical characteristics and disease associations, and estimate the incidence of hypereosinophilia in the hospital and geographic populations.

METHODS

A retrospective chart review included patients younger than 18 years presenting to a tertiary pediatric medical center (January 1, 2008, to May 31, 2017) with absolute eosinophil counts (AECs) greater than or equal to 1.50 thousand eosinophils/microliter (K/μL) recorded on at least 2 occasions at least 4 weeks apart (N = 176). Clinical characteristics, laboratory values, treatment course, and associated diagnoses were evaluated.

RESULTS

The most common cause of hypereosinophilia in this cohort was secondary hypereosinophilia. Atopic dermatitis, graft-versus-host disease, sickle cell disease, and parasitic infections were the most common conditions associated with hypereosinophilia. Median age at diagnosis was 4.6 (interquartile range, 1.5-10.5) years. Median peak AEC was 3.16 (2.46-4.78) K/μL. Hypereosinophilia occurred most frequently in patients aged between 6 and 11 years (24.4%) and younger than 1 year (18.2%). Patients with neoplasms and immune deficiencies had significantly higher peak AECs than did patients with overlap hypereosinophilic syndrome and atopic diseases (P < .0001).

CONCLUSIONS

Pediatric hypereosinophilia has an incidence of 54.4 per 100,000 persons per year, with children younger than 1 year and aged 6 to 11 years accounting for most affected patients. Pediatric hypereosinophilia is not uncommon and remains underrecognized, highlighting a need for clinicians to identify patients who meet criteria for hypereosinophilia and to pursue a thorough evaluation.

An Approach to the Evaluation of Persistent Hypereosinophilia in Pediatric Patients

Hypereosinophilia (HE) is currently defined by a peripheral blood absolute eosinophil count (AEC) of ≥1,500 cells/microL. Although mild blood eosinophilia (AEC 500–1,500 cells/microL) is observed relatively frequently within the pediatric population, persistent HE is uncommon and should prompt additional clinical evaluation. While the clinical manifestations and underlying etiologies of HE in adults have been well-characterized, there is a paucity of data on HE in children. Limited evidence suggests that many similarities between adult and pediatric HE likely exist, but some important differences remain between these populations. The evaluation of HE in children can be challenging given the broad differential diagnosis, which includes primary hematologic disorders and secondary eosinophilia in which the increased eosinophil levels are propagated by disease states that promote eosinophil production and survival. On the basis of the underlying etiology, clinical manifestations can range from benign, self-resolving elevations in the AEC to life-threatening disorders with the potential for significant end-organ damage. Given the broad differential diagnosis of HE, it remains essential to systematically approach the evaluation of unexplained HE in children. This review will discuss the differential diagnosis for pediatric HE, highlighting etiologies that are more prevalent within the pediatric population. Additionally, a summary of the epidemiology of pediatric HE will be presented, with focus on some of the differences that exist between pediatric and adult HE. Finally, a directed approach to the diagnostic evaluation of children with HE will be discussed.

Acute Lymphoblastic Leukemia with Hypereosinophilia in a Child: Case Report and Literature Review

Background: Hypereosinophilia in children can be primary or secondary. Numerous malignant diseases can cause hypereosinophilia, but it is seldom caused by acute lymphoblastic leukemia (ALL). In the event of protracted hypereosinophilia, it is extremely important to make a correct differential diagnosis. Case presentation: We present the case of an 11-year-old boy of Moroccan origin with ALL with hypereosinophilic onset (eosinophils in peripheral blood, 10,000/µL) in the absence of other signs of neoplastic disease, and compare this case with 61 similar cases in the literature. Following hospital admission, the patient initially presented with headache-caused nocturnal awakenings, evening fever, and cough, and he also lost approximately 7 kg in weight in a month not associated with sweating or itching. We first performed bone marrow aspiration, which showed an increase in eosinophils without cellular morphological abnormalities, and bone marrow immunophenotyping showed that 4.5% of cells had a phenotype compatible with lymphoid blasts. A lumbar puncture was negative. Given the poor marrow involvement, it was necessary to repeat a new bone marrow aspiration two days later, which showed an increase in blasts to 14%. A concomitant bone marrow biopsy showed an infiltration of blasts typical of B-cell ALL equal to 20–30% with associated hypereosinophilia. Cytogenetic analysis showed an hyperdiploid karyotype: 53–55, XY, +X, add(1)(q21q25), +4, +9, +10, +14, +2, +1, +21/46, XY. Conclusions: ALL is one of the possible causes of persistent hypereosinophilia. In patients with ALL and hypereosinophilia, peripheral hypereosinophilia can precede the appearance of blasts. Due to the negative prognosis and the increased risk of complications in these patients, bone marrow aspiration and biopsy are recommended if common causes of secondary hypereosinophilia are excluded.

Hypereosinophilia in Acute Lymphoblastic Leukemia: Two Cases with Review of Literature

Eosinophilia is rare in acute leukemia at presentation. Discrete reports and case studies in recent years have created significant interest in the field of "Acute leukemia with eosinophilia". We herein present two cases of eosinophilia in association with acute lymphoblastic leukemia with brief review of literature in this field. First case is about 21-year-old female who presented with mediastinal mass along with leukocytosis and hypereosinophilia. On evaluation, she was found to have T cell acute lymphoblastic leukemia. After ruling out benign causes of eosinophilia, she was treated with modified BFM-90 protocol. Her eosinophilia resolved after 4 weeks of induction therapy. Second case is about 32-year-old male who was diagnosed as a case of mixed phenotype leukemia (B cell/myeloid type) along with severe eosinophilia. His hypereosinophilia finally resolved by week 16 of modified BFM-90 protocol. Diagnosing ALL is challenging when eosinophilia is the initial presentation. These two cases emphasize on the importance of considering ALL amongst one of the etiological causes of eosinophilia as delay in diagnosis endangers patient's life at risk. Also eosinophilia per se is an independent poor risk factor, hence prompt diagnosis and early treatment is the key in all such cases.