What are the symptoms of Loeffler syndrome?

Loeffler's syndrome is a rare form of eosinophilic lung disease, with symptoms that are usually transient, self-limited, and benign, lasting less than one month (usually 6-12 days). The etiology of Loeffler syndrome is mainly thought to be due to an allergic reaction to the pulmonary migration of helminthic larvae, namely roundworms (A. lumbricoides), hookworms and strongyloides.

Loeffler syndrome is a transient respiratory disease associated with eosinophilia and radiographic opacities.
In pathophysiology, Loeffler syndrome is thought to be related to the passage of parasites through the lungs through their life cycle in the human body. After ingestion of Ascaris lumbricoides eggs, the larvae hatch in the intestine and penetrate the mesenteric lymphatics and venules to enter the pulmonary circulation. They reside in the pulmonary capillaries and continue the cycle by migrating through the alveolar walls. Finally, they move up the bronchial tree and are swallowed into the esophagus, return to the intestinal tract, and mature. This process takes about 10-16 days after eating roundworm, hookworm, and strongyloidiasis eggs.
In addition, other parasites, such as Necator americanus, Ancylostoma duodenale and Strongyloides stercoralis, have cycles similar to ringworm, with migration of larval forms through the alveolar wall. Some of these parasites may not be ingested orally but enter the host's body through the skin.
Recently, Loeffler syndrome has also been shown to be associated with the use of a number of drugs, including antibiotics (ethambutol, isoniazid, nitrofurantoin, penicillin, tetracyclines, clarithromycin), anticonvulsants (carbamazepines) , phenytoin, valproic acid, ethambutol), anti-inflammatory and immunosuppressive drugs (aspirin, azathioprine, beclomethasone, methotrexate, naproxen, diclofenac, fenbufen, ibuprofen, phenylbutazone, piroxicam) and others (bleomycin, captopril, chlorpromazine) .
In most cases, Loeffler syndrome is considered a benign, self-limiting disease with no significant morbidity and no reported deaths. Because young children are exposed to contaminated soil and exhibit hand-and-mouth behavior more often than adults, children have a higher incidence of intestinal worm disease and Loeffler syndrome. Symptoms of Loeffler syndrome usually subside within 3-4 weeks or shortly after drug withdrawal if drug-induced pulmonary eosinophilia is suspected.

Symptoms of Loeffler syndrome are usually mild and tend to resolve on their own after a few days or at most 2-3 weeks. Dry cough is the most common symptom; In addition, the patient may have difficulty breathing, wheezing. Some patients may experience muscle pain, loss of appetite, and urticaria.
The above symptoms usually appear after 10-16 days when eating roundworm eggs. Similar incubation periods have also been described in Loeffler syndrome associated with infection with N americanus, A duodenale or S stercoralis. A few patients had a travel-related history, which is a risk factor for exposure to parasites.
In cases where drug-related Loeffler syndrome is suspected, the patient should have evidence of the use of the drugs that can cause eosinophilia mentioned above.
On examination, the physician may hear crackles or wheezing in a patient with Loeffler syndrome. In contrast, patients with drug-induced pulmonary eosinophilia often have crackles on auscultation.

Because symptoms of Loeffler syndrome are often vague, nonspecific, and often transient, diagnosis requires the following supportive tests:
Peripheral blood cell analysis : Results show leukocytosis Blood eosinophils are mild, usually 5-20%. If eosinophils account for 40%, the cause should be thought to be drug; Stool smear: Parasites and eggs can be found in the stool for 6-12 weeks after the primary infection. However, at this point, the pulmonary symptoms are self-limited or have completely disappeared; Immunoglobulin E (IgE) level: This level may be elevated; Sputum or gastric fluid analysis: Larvae are sometimes found in sputum and gastric aspirate at the time of pulmonary symptoms; Bronchoalveolar lavage: Eosinophil count may be elevated; Imaging tests: Chest X-ray showed opacities moving from 12-20 days before. However, lung lesions observed on radiographs may disappear completely within 2-4 weeks. For drug-induced pulmonary eosinophilia, radiographic abnormalities should completely resolve several weeks after discontinuation of the suspected drug; Histological analysis: Lung lesions showed increased eosinophil infiltration occurring in the bronchi and bronchioles, in the alveoli and in the interstitium. However, parasitic forms are usually not found in the lungs.

Treatment and monitoring of Loeffler syndrome can be done on an outpatient basis, the patient does not need to be hospitalized. Patients can be physically active and have the same nutritional regimen as usual, without any special abstinence.
Since the symptoms in most patients with Loeffler syndrome are usually self-limiting, no specific treatment for this disease is necessary. If pulmonary eosinophilia is drug-induced, the patient should discontinue the drug suspected of causing the disease. Conversely, if parasitic infection is thought to be the cause, the patient should be prescribed an appropriate dewormer. If the severity of the disease is severe or the remission is slow, in both situations, systemic corticosteroid therapy will be highly effective, providing rapid symptom improvement.
In addition, to prevent as well as to prevent re-infection, each person needs to be built with a sense of good hygiene, wash hands with soap, eat cooked food and drink hot, build a house with a hygienic fecal treatment system birth, combined with educational campaigns on eliminating the use of outdated latrines, especially in rural areas. For children, parents need to guide children to wash their hands often with soap, do not put their hands in their mouth, quit the habit of biting nails and walking barefoot. For patients with established drug-induced pulmonary eosinophilia, future use of the offending drug should be avoided.
To summarize, Loeffler's syndrome is a condition in which eosinophils are elevated in the lungs due to parasitic infections or drug use. Although the symptoms of Loeffler syndrome are usually mild and the duration of the illness is short, patients are often susceptible to recurrence if the cause is not identified and precautions are taken. Therefore, building hygiene habits is an effective way to actively prevent Loeffler syndrome, especially in children. Currently, Vinmec International General Hospital is one of the leading prestigious hospitals in the country, trusted by a large number of patients for medical examination and treatment. Not only the physical system, modern equipment: 6 ultrasound rooms, 4 DR X-ray rooms (1 full-axis machine, 1 light machine, 1 general machine and 1 mammography machine) , 2 DR portable X-ray machines, 2 multi-row CT scanner rooms (1 128 rows and 1 16 arrays), 2 Magnetic resonance imaging rooms (1 3 Tesla and 1 1.5 Tesla), 1 room for 2 levels of interventional angiography and 1 room to measure bone mineral density.... Vinmec is also the place to gather a team of experienced doctors and nurses who will greatly assist in diagnosis and detection. early signs of abnormality in the patient's body. In particular, with a space designed according to 5-star hotel standards, Vinmec ensures to bring the patient the most comfort, friendliness and peace of mind.

Reference sources: emedicine.medscape.com,merckmanuals.com, impe-qn.org.vn