Löffler's syndrome is a disease in which

eosinophil Eosinophils, sometimes called eosinophiles or, less commonly, acidophils, are a variety of white blood cells (WBCs) and one of the immune system components responsible for combating multicellular parasites and certain infections in vertebrates. A ...

s accumulate in the lung in response to a

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

infection. The parasite can be ''

Ascaris ''Ascaris'' is a genus of parasite, parasitic nematode worms known as the "small intestinal roundworms", which is a type of parasitic worm. One species, ''Ascaris lumbricoides'', affects humans and causes the disease ascariasis. Another species ...

'', ''

Strongyloides stercoralis ''Strongyloides stercoralis'' is a human pathogenic parasitism, parasitic nematode, roundworm causing the disease strongyloidiasis. Its common name in the US is threadworm. In the UK and Australia, however, the term ''threadworm'' can also refe ...

, or

Dirofilaria immitis ''Dirofilaria immitis'', also known as heartworm or dog heartworm, is a parasitic roundworm that is a type of filarial worm, a small thread-like worm, that causes dirofilariasis. It is spread from host to host through the bites of mosquitoes ...

'' which can enter the body through contact with the soil. The symptoms of Löffler's syndrome include those of a parasitic infection such as abdominal pain and cramping, skin rashes and fatigue. Löffler's syndrome itself will cause difficulty breathing,

wheeze A wheeze is a continuous, coarse, whistling sound produced in the respiratory airways during breathing. For wheezes to occur, some part of the respiratory tree must be narrowed or obstructed (for example narrowing of the lower respiratory tract ...

, coughing as well as a fever.

Diagnosis

The diagnosis of Loffler's syndrome can be challenging, as the diagnostic criteria can be vague and consistent with a multitude of diseases or conditions. The disease's developmental trajectory is mostly unknown. Upon examination of symptoms, a doctor will likely request a chest x-ray looking for migratory

pulmonary infiltrate A pulmonary infiltrate is a substance denser than air, such as pus, blood, or protein, which lingers within the parenchyma of the lungs. Pulmonary infiltrates are associated with pneumonia, tuberculosis, and sarcoidosis. Pulmonary infiltrates can b ...

, and blood testing, to confirm a diagnosis. Symptoms tend to be brief, but can range from mild to severe and include: fever, vomiting, increased respirations or difficulty breathing, cough, wheeze, and rash. Symptoms typically follow an exposure to allergens or certain drugs, and last approximately two weeks. Eosinophilia is the main feature of diagnostic criteria for Loffler's syndrome. Eosinophils are white blood cells that fight infection by destroying foreign substances in the body. This increase is determined through a blood test called a complete blood count, or CBC. A result of over 500 cells/mcL (cells per microliter of blood) is considered elevated. The normal range for eosinophils is less than 350 cells/mcL.

Prevention

While the outcomes of this syndrome have never led to death, the symptoms can last anywhere from 2 to 4 weeks after the parasite enters the body. Prevention of this syndrome is education-based, consisting of educating individuals on proper handwashing techniques, as well as how to correctly dispose of feces.

Epidemiology

This syndrome can be found anywhere. However, it is abnormally prevalent in tropical areas, showing higher prevalence in men than women. This syndrome is also exceedingly common in the warm damp parts of the world. The syndrome is also more likely to be contracted by small children since they spend an increased amount of time outside in the dirt. While it is still a mystery why the prevalence is higher in Indians, the warm damp environment is a perfect place for the parasites to grow and thrive. The epidemiological aspect of Löffler's syndrome isn't well known since there have been minimal statistics reported on the topic.

History

In 1909 a man named H. French first described the condition. Then in 1932 Wilhelm Löffler /sup> drew attention to the disease in cases of

eosinophilic pneumonia Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kind ...

caused by the parasites ''

Ascaris lumbricoides ''Ascaris lumbricoides'' is a large parasitic worm that causes ascariasis in humans. A Nematoda, roundworm of genus ''Ascaris'', it is the most common parasitic worm in humans. An estimated one-sixth of the human population is at some point infe ...

'', /sup> ''

'' and the

hookworm Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, an ...

s ''

Ancylostoma duodenale ''Ancylostoma'' is a genus of nematodes that includes some species of hookworms. Species include: : ''Ancylostoma braziliense'', commonly infects cats, popularly known in Brazil as ''bicho-geográfico'' : ''Ancylostoma caninum'', commonly infec ...

'' and ''

Necator americanus ''Necator americanus'' is a species of hookworm (a type of helminth) commonly known as the New World hookworm. Like other hookworms, it is a member of the phylum Nematoda. It is an obligatory parasitic nematode that lives in the small intestine ...

''. Finally in 1943 the condition was called tropical eosinophilia by RJ Weingarten, and later officially named Löffler's syndrome. The most well-known case of Löffler's syndrome was in a young boy from Louisiana. He arrived at the hospital reporting a high fever after three days, as well as having rapid breathing. "He was hospitalized and treated with supplemental oxygen, intravenous methylprednisolone, and nebulized albuterol." The boy's symptoms quickly subsided and upon further investigation it was discovered that the boy worked caring for pigs. A test was then performed on the pigs' fecal matter and surrounding soil; it contained the parasite that had caused the boy's ailment. Another incident again involved a young boy who had been experiencing vomiting and a fever for a span of 3 months. When the doctors finally took an echocardiograph of the child they discovered that the "patient's admission blood count showed leukocytosis with an abnormally elevated level of peripheral eosinophils." The child was then diagnosed with Löffler's endocarditis, and immediately began immunosuppressive therapy to decline the eosinophilic count. Although Löffler only described eosinophilic pneumonia in the context of infection, many authors give the term "Löffler's syndrome" to any form of acute onset pulmonary eosinophilia no matter what the underlying cause. If the cause is unknown, it is specified and called "simple pulmonary eosinophilia". Cardiac damage caused by the damaging effects of eosinophil granule proteins (e.g.

major basic protein Eosinophil major basic protein, often shortened to major basic protein (MBP; also called Proteoglycan 2 (PRG2)) is encoded in humans by the ''PRG2'' gene. Function The protein encoded by this gene is the predominant constituent of the crystalli ...

) is known as Loeffler endocarditis and can be caused by idiopathic eosinophilia or eosinophilia in response to parasitic infection.

References

External links