Overview
Jaw-worm nematode disease is a kind of rare helminthic larval migratory disease in China, and the pathogen is the third stage larva of Echinococcus japonicus. Clinically, it is characterized by migratory subcutaneous masses and increased blood eosinophilia. In addition, the third stage larvae of Echinococcus granulosus can also invade deep tissues and organs, such as the brain, lungs, eyes, liver, kidneys, etc., causing visceral Echinococcus granulosus larvae.
Causes
Humans are often infected by eating raw or undercooked freshwater fish containing third-stage larvae.
Symptoms
Patients may develop low-grade fever, generalized malaise, urticaria, nausea, vomiting, and epigastric pain 24 to 48 hours after infection. According to the difference in the site of migration of the larvae of Echinococcus granulosus in the human body, it can be divided into two clinical types: cutaneous jaw nematode disease and visceral jaw nematode disease.
1. Cutaneous jawworm disease
Most of the larvae migrate in the subcutaneous tissues 3 to 4 weeks after infection, resulting in symptoms and signs, the most common sign is the appearance of local skin migratory masses, which may appear intermittently. The most common sign is the appearance of localized migratory skin masses, which may appear intermittently. Each appearance may last for 1 to 2 weeks. Localized skin edema is non-invasive with pain, itching, or erythema. The path of migration may be hyperpigmented. With prolongation of the disease, the number of episodes may decrease, and the symptoms may be less severe and the duration of the episodes shorter. The disease sometimes presents as a runny rash, skin nodules or abscesses, and occasionally the larvae may burrow out of the skin on their own.
2. Visceral jaw nematode disease
(1) Liver lesions The larvae migrate to the liver, which may cause vague pain or distension in the right upper abdomen, and liver enlargement is often accompanied by loss of appetite, nausea, fatigue and other symptoms.
(2) Central nervous system lesions Neurogenic myelitis, meningoencephalitis and subarachnoid hemorrhage are more common. If the larvae migrate to the spinal cord cavity, they can stimulate the nerve roots, causing severe pain with burning sensation. A few days later, limb paralysis or paraplegia occurs. Paralysis is mainly paraplegia with urinary retention. If the larvae burrow into the skull, it can cause meningeal and brain tissue lesions, severe headache, projectile vomiting, impaired consciousness, cerebral nerve paralysis or limb paralysis. Larvae drilling into the subarachnoid space can easily cause hemorrhage, and the patient manifests sudden severe headache, vomiting, and meningeal irritation signs. The cerebrospinal fluid is bloody and contains many eosinophils.
(3) Lung lesions often occur after months or years of cutaneous nematode infections, with cough, chest pain, shortness of breath and hemoptysis, which may lead to pleural effusion or blood accumulation. Occasionally, the worms may be coughed up with sputum.
(4) Ocular lesions can cause external ocular lesions and intraocular lesions. The former manifests as periorbital inflammation, with eye pain, tearing, photophobia, redness and swelling around the eyes. The latter manifests as iritis, anterior chamber or vitreous hemorrhage, retinal detachment, etc., which may lead to blindness in severe cases. With the eye slit lamp examination can be found in the conjunctiva, anterior chamber or vitreous body of the echinococcus nematodes larvae.
(5) Gastrointestinal lesions The larvae parasitize in the intestinal wall to form intestinal wall mass, which can cause incomplete intestinal obstruction, abdominal pain, abdominal distension, diarrhea, blood in the stool, vomiting, and other symptoms, and occasionally a mass can be found in the abdomen.
(6) Urinary tract lesions Rarely, the larvae may pass through the bladder tissue and be excreted with urine. In this case, hematuria and foreign body sensation in urination may occur.
Examination
1. Blood picture
The total number of leukocytes in peripheral blood is mildly increased, and the proportion of eosinophils is often obviously elevated.
2. Pathologic examination
Tissue biopsy of subcutaneous mass is eosinophilic granuloma.
3. Slit lamp examination
The eye slit-lamp examination may reveal nematode larvae in the subconjunctiva, anterior chamber or vitreous humor.
Diagnosis
Diagnosis can be made on the basis of epidemiologic data, clinical manifestations, and laboratory tests.
Treatment
1. Supportive and symptomatic treatment
In severe cases, such as patients with cerebral jaw nematode disease, when intracranial pressure rises, 20% mannitol injection should be used in time for rapid intravenous drip, and furosemide and adrenocorticotropic hormone should be added if necessary in order to reduce the intracranial pressure and prevent the occurrence of cerebral herniation.
2.Pathogen treatment
Treatment with albendazole has good effect. Oral treatment program for 3 weeks. In the second week of the course, the larvae of Echinococcus granulosus are stimulated by the drug and become excited, struggle, and sometimes drill out of the skin, but there is a possibility of aggravation of the disease. Generally, the disease can be cured after one course of treatment. Individual cases may require two courses of treatment. Blood eosinophil count gradually returns to normal after cure.
Ivermectin is a broad-spectrum antiparasitic drug with strong killing effect on nematode parasites such as roundworm, whipworm, hookworm banana filaria, Malayan filaria, and onchocerca volvulus, etc. However, it is not suitable for infants, young children and pregnant women.
Oculomandibular nematode disease is treated with surgical removal of echinococcal nematode larvae.