Eosinophilic leukemoid reaction in a male adolescent with Löeffler syndrome.

The Löeffler syndrome is characterized by pulmonary infiltrates on a chest x-ray accompanied with peripheral eosinophilia. In this article, we have highlighted the Löeffler syndrome complicated with a eosinophilic leukemoid reaction in a previously healthy boy. The patient was treated with albendazole for five days, with a successful result. In countries where parasitic diseases are endemic, the Löeffler syndrome must always be considered in patients who present with a eosinophilic leukemoid reaction.

INTRODUCTION

Pulmonary eosinophilia caused by a larval passage is defined as Löeffler syndrome, and is also referred to as a simple pulmonary eosinophilia.[1] Löeffler, the person who first identified this syndrome, reported that most cases were caused by Ascaris.[12] Herein, we report the case of a patient with Löeffler syndrome, accompanied by eosinophilic leukemoid reaction.

CASE REPORT

A previously healthy 16-year-old male presented with a 10-day history of shoulder and back pain. He denied having a cough, sputum or dyspnea. He was investigated for these symptoms by a local physician and was observed to have profound leukocytosis (60,000/mm3). The patient was then referred to our hospital for further evaluation of the underlying cause of his high leukocyte count. He reported not using any drug, but had a history of eating soil. He began defecating roundworms a few months ago before presentation.

Physical examination showed he was healthy in appearance; there was mild splenomegaly, without hepatic enlargement. The musculoskeletal examination was normal. Laboratory findings were as follows: Hemoglobin: 11 g/dL; white blood cell count: 57,600/mm3 with 15% polymorphonuclear leukocytes, 77% eosinophils, and 8% lymphocytes; platelet count: 358,000/mm3; C-reactive protein (CRP): 3 mg/L; and erythrocyte sedimentation rate: 32 mm/hour. The renal and hepatic function tests were normal. The serum quantitative IgE level was 2800 mg/dL and the IgG, IgA, and IgM levels were normal for his age. Human immunodeficiency virus (HIV) serology was negative. The chest x-ray showed perihilar and pericardial interstitial infiltration in both the lungs. Echocardiography was normal.

On account of a high degree of eosinophilia, the patient underwent bone marrow aspiration, and an examination of the aspirate showed a marked increase in the eosinophilic series, which were of normal morphology and the other series were normal. The serologies of Fasciola hepatica, Toxocara, and the hydatid cyst were negative. Stool examinations were negative for parasites and eggs. A thoracic CT showed multiple, peripherally localized nodular lesions, with a surrounding ground-glass opacity or halo in the superior lobes of both the lungs [Figure 1]. Abdominal ultrasonography (USG) showed mild hepatosplenomegaly and multiple reactive para-aortic lymphadenopathies. Albendazole 2 × 400 mg for five days was started based on a suspicion of the Löeffler syndrome. He was discharged at the end of the treatment, on the fifth day of hospitalization. Three weeks post discharge, his white blood cell (WBC) count returned to normal (9100/mm3, with 10% eosinophils). The patient was still asymptomatic six months after treatment and the control chest x-ray was normal.

Figure 1

Multiple peripheral nodular lesions in the thorax CT scan

DISCUSSION

Eosinophils are predominantly found in tissues. The normal mean peripheral blood eosinophil count is 500 cells/µL1, and eosinophilia is defined as mild (500 – 1500 cells/µL), moderate (1500 – 5000 cells/µL), or severe (>5000 cells/µL).[34] A eosinophilic leukemoid reaction is defined as a WBC count >30,000/mm3, with >30% eosinophils. Parasitic infection is the most common cause of eosinophilia worldwide, and can also induce a eosinophilic leukemoid reaction. Eosinophilia occurs most commonly during the pulmonary migratory phase from the gastrointestinal tract.[4]

The Löeffler syndrome is a simple pulmonary eosinophilia caused by parasites, especially Ascaris, Strongyloides, Paragonimus, Trichinella, and Toxocara or drug reactions.[15] It is characterized by pulmonary infiltrates on chest x-ray and peripheral eosinophilia. Patients with the Löeffler syndrome can have mild respiratory symptoms or be asymptomatic; anorexia, malaise, and weight loss can also be observed. Patients are frequently diagnosed via incidental chest x-ray findings or blood count results.[5] The patient who presented to us did not have any respiratory symptoms. The diagnosis of the Löeffler syndrome relies on a suggestive history, typical imaging findings, and demonstration of alveolar eosinophilia, with/without markedly elevated peripheral blood eosinophilia.[6] The erythrocyte sedimentation rate (ESR), CRP, and immunoglobulin E (IgE) levels can be elevated, but are nonspecific. In the patient referred to in this article, the Löeffler syndrome was diagnosed based on a high eosinophil count and IgE level, as also by abnormal chest x-ray findings.

As our patient had a history of eating soil and worm defecation, parasitic infestation was considered to be the etiological agent. Generally parasitosis is acquired by exposure to contaminated soil, consumption of uncooked food that has been grown in contaminated soil or in soil irrigated with inadequately treated wastewater. A. lumbricoides is the most common worm infection in Turkey.[7] The period from intrapulmonary larval stage to the presence of eggs in the feces is eight to ten weeks.[8] This patient had a 10-day history of symptoms, and as expected, the stool examination was negative. A history of worm defecation in this patient with Löeffler syndrome indicated that more than one phase of the parasitic cycle may have occurred simultaneously on account of parasitic re-infection.

CONCLUSION

In conclusion, in the case of a eosinophilic leukemoid reaction, even without respiratory symptoms, a chest X-ray should be taken, to investigate the Löeffler syndrome.