Tropical eosinophilia (TE) occurs in patients who have filariasis, which is an infection caused by certain types of roundworm, exemplified by Wuchereria bancrofti and Brugia malayi [1]. The presence of these parasites in the body leads to an exaggerated immune response in some individuals characterized by markedly high levels of eosinophils in the blood and even higher concentrations in the lungs [2]. This immune response, in turn, provokes transient episodes of acute respiratory symptoms such as wheezing, coughing, shortness of breath and chest pain, often worse at night [3]. Systemic symptoms such as fever, loss of weight and appetite, lymphadenopathy, hepatomegaly, and splenomegaly may also occur, although, in a small percentage of patients, no pulmonary symptoms are present.

TE is most frequently seen in areas where filarial infections are endemic, however, cases in non-endemic areas have been reported, aided by travel and immigration, albeit some cases are misdiagnosed due to failure to recognize the syndrome [4] [5]. Males are four times more affected by the illness than females. More serious clinical manifestations include permanent widening of the airways, pneumothorax, consolidation of the lungs and granulomas. Cardiac activity can also be affected, and this is demonstrated by electrocardiogram (ECG) abnormalities [6]. Changes in the lung tissue that result in chronic disease have also been reported in a minority of cases, where symptoms do not resolve despite adequate treatment with diethylcarbamazine (DEC) [7].

• Pulmonary Disorder

  Eosinophilia in Pulmonary Disorders. Immunol Allergy Clin North Am. 2015 Aug. 35 (3):477-92. [Medline]. [emedicine.medscape.com]

• Nocturnal Wheezing

  It is characterized by episodic nocturnal wheezing and coughing, strikingly elevated eosinophilia, and diffuse reticulonodular infiltrations of the lung. Sometimes the lymph nodes and spleen are greatly enlarged. [medical-dictionary.thefreedictionary.com]

  It is characterized by cough, dyspnea, and nocturnal wheezing with diffuse reticulonodular infiltrates in chest radiographs and marked peripheral blood eosinophilia. [1] Long-term sequelae are pulmonary fibrosis with chronic respiratory failure. [2] Pulmonary [atmph.org]

• Orthopnea

  There was no history of orthopnea, paroxysmal nocturnal dyspnea, chest pain, abdominal distension, or decreased urine output. [atmph.org]

• Exertional Dyspnea

  (70%): Exertional Dyspnea (45%): Wheeze (28%): Chest pain: Wheezing/Rales, or Diffuse Rhonchi (20% of cases have normal lung exam) (see [[Obstructive Lung Disease]]) Constitutional Weight Loss (52%): Fatigue (75%): Anorexia (42%): Fever (25%): Lymphadenopathy [mdnxs.com]

• Pansystolic Murmur

  A soft, grade 2/6 pansystolic murmur was heard over the tricuspid area. There were inspiratory fine crepitations and rhonchi all over the chest. The liver was palpable 2 cm below right costal margin. [atmph.org]

• Impulsivity

  Cardiac impulse was right ventricular in type. Pulmonary second sound was loud and palpable. A soft, grade 2/6 pansystolic murmur was heard over the tricuspid area. There were inspiratory fine crepitations and rhonchi all over the chest. [atmph.org]

Patient history is important, especially in non-endemic areas, as a recent travel history to tropical regions may give diagnostic clues. Laboratory investigations such as white cell count as well as measurement of antibody titers are performed. In individuals with TE, leukocytes are increased, with a predominance of eosinophils. Furthermore, there are high titers of specific as well as non-specific immunoglobulins (Ig), namely IgE, IgG, and IgM, in response to filarial antigens [8].

Pulmonary function tests are necessary, and reveal a mixed picture of obstructive and restrictive lung disease, with a decrease in parameters such as the forced expiratory volume (FEV) and the diffusing capacity for carbon monoxide (DLCO) [7] [9]. In some cases, a purely restrictive picture is seen.

In addition, the following studies are also done:

• Arterial blood gas analysis: May reveal lower than normal concentrations of oxygen due to a ventilation-perfusion mismatch [3].
• Chest X-ray: This may be normal in up to one fifth of patients. Usually, widespread nodular opacities are visible, similar to those seen in miliary tuberculosis.
• Computerized tomography scan: Useful in showing structural lung damage such as bronchiectasis [10].
• Bronchoscopy and bronchoalveolar lavage: This allows the visualization of inflammation of the parenchyma as a direct consequence of the presence of a large number of eosinophils in the lungs [2]. Furthermore, anti-filarial antibodies, as well as, nonspecific antibodies can also be seen.
• Lung biopsy: Biopsy is usually done in the context of chronic disease which is first confirmed via spirometry, in the years following treatment.

• Right Axis Deviation

  Electrocardiogram recorded sinus rhythm with right axis deviation and right ventricular hypertrophy. 2D-echocardiography (ECHO) revealed massive dilated right ventricle and atrium with dysfunction with right ventricular systolic pressure (RVSP) of 72 [atmph.org]

  Echocardiography showed right axis deviation with right ventricular hypertrophy, and chest radiography revealed pulmonary edema. [doi.org]

• Wuchereria Bancrofti

  It is caused by immunologic hyperresponsiveness to the filarial parasites Wuchereria bancrofti or Brugia malayi. [ncbi.nlm.nih.gov]

  Definition / general Due to microfilaria of Wuchereria bancrofti or Brugia malayi, which circulate in pulmonary capillaries and cause an immediate type of eosinophilic hypersensitivity reaction Patients have high levels of IgE and high titers of filarial [pathologyoutlines.com]

  Tropical (pulmonary) eosinophilia, or TPE, is characterized by coughing, asthmatic attacks, and an enlarged spleen, and is caused by Wuchereria bancrofti, a filarial infection. It occurs most frequently in India and Southeast Asia. [en.wikipedia.org]

• Dirofilaria Immitis

  No significant difference was observed between this antigen and that prepared from Dirofilaria immitis. [ncbi.nlm.nih.gov]

  IgG enzyme-linked immunosorbent assay showed a high titer against Dirofilaria immitis. Microfilaria were not detected in blood sampled at night. He was given a diagnosis of tropical eosinophilia. We could not give diethyl-carbamazine. [jstage.jst.go.jp]

  Immitis antigen, etc.): elevated (diagnosticaly useful but may have lower titer elevation in helminthic infections, due to cross-reactivity) ESR: may be elevated in advanced disease Blood C/S and exam: negative EKG: may be abnormal Echo: may show pericardial [mdnxs.com]

  immitis Pulmonary lesion Tropical and subtropical, including Australia Serology None Hookworm disease Ancylostoma duodenale Loeffler’s-like syndrome Tropical and subtropical areas Stool Albendazole * Loeffler’s-like syndrome: transient pulmonary infiltrates [mja.com.au]

• Restrictive Pulmonary Function

  Pulmonary function test (PFT) revealed moderate obstruction with significant bronchodilator response with superimposed restriction. [atmph.org]

• Amyloid Plaque

  Read More Full Text HTML Download PDF Figure 1: Alzheimer's disease (AD) is characterized by neuronal death, which is usually correlated with the appearance of amyloid plaques and neurofibrillary tangles (NFTs). (a) The Aβ pathway leading... [doi.org]

• Neurofibrillary Tangle

  Read More Full Text HTML Download PDF Figure 1: Alzheimer's disease (AD) is characterized by neuronal death, which is usually correlated with the appearance of amyloid plaques and neurofibrillary tangles (NFTs). (a) The Aβ pathway leading... [doi.org]

• Ventricular Hypertrophy

  Electrocardiogram recorded sinus rhythm with right axis deviation and right ventricular hypertrophy. 2D-echocardiography (ECHO) revealed massive dilated right ventricle and atrium with dysfunction with right ventricular systolic pressure (RVSP) of 72 [atmph.org]

  Echocardiography showed right axis deviation with right ventricular hypertrophy, and chest radiography revealed pulmonary edema. [doi.org]

Rapid amelioration of signs and symptoms with diethylcarbamazine treatment is a hallmark of TPE. [doi.org]

The eosinophil count often falls dramatically within 7–10 days of starting treatment. [en.wikipedia.org]

Early diagnosis and treatment with diethylcarbamazine (DEC) may prevent progressive pulmonary disease. [mja.com.au]

Following treatment with a standard 3-week course of diethylcarbamazine, there was a significant fall in lung eosinophils (p less than 0.001). [ncbi.nlm.nih.gov]

Signs and symptoms, pathology, pathogenesis, etiology, course and prognosis, and treatment are discussed. Evidence is preponderantly in favor of the etiology in all cases being nematode larvae invasions of the liver and other viscera. [pediatrics.aappublications.org]

PROGNOSIS AND TREATMENT The median survival time for patients with CFA is approximately 5 years although mortality is very high with the acute form. [medassignments.com]

Prognosis Löffler's disease tends to follow an uncomplicated course and resolve completely within a month. Recurrence occurs only if infection recurs or the offending drug is reintroduced. [patient.info]

[…] mention TPE as a cause of pulmonary hypertension and isolated heart failure, but literature does suggest that some TPE patients may develop pulmonary hypertension if not timely diagnosed. [8] Development of pulmonary hypertension usually confers to a poor prognosis [atmph.org]

The historical development of evidence supporting the filarial etiology of TE was reviewed. [ncbi.nlm.nih.gov]

 Associated with Connective Tissue Disease or Vasculitis Eosinophilic Lung Disease Classification of PIE by Etiology Eosinophilic Lung Disease Specific Etiology  Drug-induced  Nitrofurantoin  Penicillin  Sulfonamides  Parasite-induced  Ascariasis [learningradiology.com]

In our modified diagnostic protocol we were able to determine the etiology in 90% of patients with ≤ RS 1000. However if the etiology is undetermined even at step-3 the cost escalates. [lungindia.com]

The etiology was unknown for two decades, but (as indicated above) it is now agreed that it is an immune hyperresponse to microfilariae. [isradiology.org]

In the group of large eozinofilia blood comes with a number of diseases with unclear etiology. This so-called infectious eosinophiles (I. A. [medicalency.com]

Epidemiology and Pathology There are some findings in the epidemiology of TPE which have not been explained. These include predominance of disease in males (4:1 male: female predominance) and an age group of 20-40 years. [isradiology.org]

A review of the geographic distribution and epidemiology of leishmaniasis in the New World. ‎ Seite 54 - Hendrix TR: Epithelial and other mucosal lesions of the jejunum in giardiasis. Jejunal biopsy studies. [books.google.de]

[…] with protease inhibitors in patients from Braşov ME Cocuz, R Silaghi, B Nedelcu, G Manea BMC infectious diseases 14 (S4), P32, 2014 2014 Early Lyme disease–current clinical and epidemiological aspects in Braşov ME Cocuz, L Rodina, IG Cocuz BMC infectious [scholar.google.com]

It is important for physicians to know the epidemiologic characteristics, clinical presentations, and treatments of choice for these conditions. [ncbi.nlm.nih.gov]

Effective strategies to prevent and treat AD remain elusive despite major efforts to understand its basic biology and clinical pathophysiology. Significant investments in therapeutic ... [doi.org]

Pathophysiology The eosinophils develop from the stem cells in bone marrow. Myeloid series cells get maturation under the influence of granulocytes colony-stimulating factor (G-CSF). [labpedia.net]

Clinical, pathophysiologic, and therapeutic considerations. Ann Intern Med. 1982 Jul. 97(1):78-92. [Medline]. Jederlinic PJ, Sicilian L, Gaensler EA. Chronic eosinophilic pneumonia. A report of 19 cases and a review of the literature. [emedicine.medscape.com]

Mutual pathophysiological relationships, but only a low correlation exist between IgE and eosinophilia ( 11 ). No guidelines are yet available for diagnostic evaluation of eosinophilia in the primary care setting. [aerzteblatt.de]

In order to prevent the long term morbidity of cardiorespiratory disability, the early signs of TPE should be recognized and the infection treated. [ncbi.nlm.nih.gov]

Prevent, evaluate, and manage diseases that can be acquired in tropical environments and foreign countries with The Travel and Tropical Medicine Manual. [books.google.de]

Effective strategies to prevent and treat AD remain elusive despite major efforts to understand its basic biology and clinical pathophysiology. Significant investments in therapeutic ... [doi.org]

Early diagnosis and treatment with diethylcarbamazine (DEC) may prevent progressive pulmonary disease. [mja.com.au]

Prevention This is largely the prevention of parasitic infestation in endemic areas. Good hygiene and hand washing before eating are also important. Historical notes Wilhelm Löffler was born in 1887 and died in 1972. [patient.info]

1. Boggild AK, Keystone JS, Kain KC.Tropical Pulmonary Eosinophilia: A Case Series in a Setting of Nonendemicity. Clin Infect Dis. 2004;39(8):1123-1128.
2. O'Bryan L, Pinkston P, Kumaraswami V, et al. Localized Eosinophil Degranulation Mediates Disease in Tropical Pulmonary Eosinophilia. Infect Immun. 2003;71(3):1337–1342.
3. Ray D, Abel R, Selvaraj KG. Epidemiology of pulmonary eosinophilia in rural South India — a prospective study, 1981–1986. J Epidemiol Community Health. 1993;47(6): 469-474.
4. Jacobson B. Public Health in Inner London. BMJ. 1992;305(6865):1344-1347.
5. Jones DA, Pillai DK, Rathbone BJ, Cookson JB. Persisting ‘asthma’ in tropical pulmonary eosinophilia. Thorax. 1983;38(9):692-693.
6. Vakil RJ. Cardiovascular involvement in tropical eosinophilia. Br Heart J. 1961;23(5):578–586.
7. Poh SC. The course of lung function in treated tropical pulmonary eosinophilia. Thorax. 1974;29(6):710-712.
8. Billa G, Thakkar K. A Case of Chronic Cough with Progressive Breathlessness in a 32 Year-old Male Health Worker -Tuberculosis?, Allergic Bronchitis?, Asthma?. Br J Med Med Res. 2014;4(35):5513-5518.
9. Nesarajah MS. Pulmonary function in tropical eosinophila. Thorax. 1972;27(2):185–187.
10. Sandhu M, Mukhopadhyay S, Sharma SK. Tropical pulmonary eosinophilia: a comparative evaluation of plain chest radiography and computed tomography. Australas Radiol. 1996;40(1):32–37.