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Tropical Eosinophilia

Tropical eosinophilia is an endemic disease that mostly affects the lungs. It is mediated by an immune hypersensitivity reaction to the presence of filarial parasites in the body.


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].

Constitutional Symptom
  • Two patients initially denied respiratory or constitutional symptoms and were referred for eosinophilia. However, each of these patients had abnormal physical examination findings (wheezing) or pulmonary function test results.[doi.org]
  • Abstract A 21-year-old man from Sri Lanka came to Japan in August 1992 and worked as a painter. He had often complained of dyspnea on exertion before coming to Japan.[jstage.jst.go.jp]
Ankle Edema
  • Jugular venous pressure was raised and ankle edema was present. 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.[atmph.org]
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]
Exertional Dyspnea
  • […] in some cases Liver, Lymph node, or Lung Bx (rarely necessary for diagnosis): demonstrate filaria (but speciation is usually difficult) Clinical Lung Involvement Cough (90%): may be nocturnal Mucoid sputum (55%) Paroxysmal Cough with Dyspnea (70%): Exertional[mdnxs.com]
  • There was no history of orthopnea, paroxysmal nocturnal dyspnea, chest pain, abdominal distension, or decreased urine output.[atmph.org]
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]
  • Seite 147 - DV, Angerer, LM, and Angerer, RC (1984) Detection of mRNAs in sea urchin embryos by in situ hybridization using asymmetric RNA probes. Dev. Biol. 101, 485-502. ‎[books.google.de]


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]
Eosinophils Increased
  • Eosinophils increases in number when there is any kind of parasitic invasion in the body. Eosinophils are directly connected to our immunological defense mechanism; they are produced in bone marrow and migrate to epithelial surfaces and skin.[planetayurveda.com]
Wuchereria Bancrofti
  • Abstract Reaginic antibodies to antigens from the human filarial parasites Wuchereria bancrofti and Brugia malayi and the animal parasite Dirofilaria immitis were studied by histamine release from basophils in 7 patients with tropical eosinophilia (T.E[ncbi.nlm.nih.gov]
  • It is caused by immunologic hyperresponsiveness to the filarial parasites Wuchereria bancrofti or Brugia malayi.[ncbi.nlm.nih.gov]
  • Tropical pulmonary eosinophilia (TPE) is a rare but serious manifestation of infection with the lymphatic filarial parasites Wuchereria bancrofti and Brugia malayi.[ncbi.nlm.nih.gov]
  • 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.[symptoma.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]
Mycobacterium Avium Complex
  • Seite 370 - Recommendations on prophylaxis and therapy for disseminated Mycobacterium avium complex disease in patients infected with the human immunodeficiency virus. ‎[books.google.de]
Restrictive Pulmonary Function
  • Ongoing chronic inflammatory process may lead to development of pulmonary fibrosis and chronic respiratory failure. [6] These restrictive pulmonary function deficits may result in pulmonary hypertension that subsequently contributes to cor-pulmonale.[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]


  • 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]
  • Leukocyte and eosinophil counts showed a rapid reduction after treatment, and although mean complement-fixing (cf) titers to Dirofilarial antigen tended to decrease, they were not significantly reduced until 5 to 6 weeks.[ncbi.nlm.nih.gov]
  • Abstract Spirometric and lung volume measurements were carried out before and after treatment with diethylcarbamazine in 19 patients with tropical eosinophilia.[ncbi.nlm.nih.gov]
  • Herein lies the importance of early diagnosis and treatment of TPE.[ncbi.nlm.nih.gov]


  • […] 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]
  • 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 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]
  • 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]


  • The historical development of evidence supporting the filarial etiology of TE was reviewed.[ncbi.nlm.nih.gov]
  • For example, in chapter 2 when listing the parasitic infections associated with eosinophilia, filariasis is omitted; however, in the chapter on etiology, several pages are devoted to filariasis and eosinophilia.[ajtmh.org]
  • […] visitors to endemic areas Requires exposure in endemic area for at least a few months Age: usually occurs in 20-40 y/o Sex: 80% of cases are males Race: Indians are most susceptible Possible relationship to Tropical Myocardial Fibrosis (unclear though) Etiology[mdnxs.com]
  •  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]
  • .—“ The etiology and pathology of eosinophilic lung ”. Am. J. trop. Med. Hyg. , 15 , 183 –180. Edeson , J. F. B. , Wilson , T. , Wharton , R. H. and Laing , A. B. G. , 1960 .—“ Experimental transmission of Britgia malayi and Brugia pahangi to man ”.[cambridge.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]
  • Epidemiology Most common in Southeast Asia, India, South Pacific Africa, South America (but cases have occurred in North American and European visitors to endemic areas Requires exposure in endemic area for at least a few months Age: usually occurs in[mdnxs.com]
  • It is important for physicians to know the epidemiologic characteristics, clinical presentations, and treatments of choice for these conditions.[ncbi.nlm.nih.gov]
  • […] 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]
Sex distribution
Age distribution


  • 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]
  • PATHOPHYSIOLOGY Femoroacetabular impingement is due to bony morphologic abnormalities of the hip joint that cause abnormal contact during motion.[cdt-babes.ro]


  • 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]
  • 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]
  • Therefore, prompt clinical suspicion and early treatment can prevent cardiopulmonary morbidity.[atmph.org]
  • 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.

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Last updated: 2019-07-11 21:03