Skin filariasis

Introduction to filariasis Filariasis is a parasitic disease caused by the parasitic filamentous system of the adult filamentous worm. It can cause elephantiasis and tropical eosinophilia. There are many types of filamentous insects that cause human infection, but mainly related to dermatology are plaque and malaria filariasis. basic knowledge The proportion of illness: 0.004% Susceptible people: more common in young adults, more common in men. Mode of infection: mosquito bites. Complications: anemia

Cause of skin filariasis

Cause of disease

Filariasis is a chronic infectious disease caused by silkworm parasites in the human lymphatic system. Humans are the terminal hosts of adults, and mosquitoes are intermediate hosts of larvae.

Pathophysiology

The adult is a milky white slender linear worm, which is dioecious and parasitic in the lymphatic vessels of the human body and continuously produces microfilariae. The microfilaria passes through the lymphatic vessels and enters the bloodstream. At night, it is concentrated in the blood vessels of the human body and gathers in the pulmonary capillaries during the daytime. If bitten by a mosquito, the microfilaria enters the mosquito stomach, and develops into a contagious young silkworm in the chest cavity of the mosquito for 1 to 2 weeks, and moves to the lower lip of the mosquito kiss. When the mosquito bites the human, the young silkworm It then invades the human body and enters the lymphatic system to develop into an adult.

Pathological changes: mainly manifested as pathological changes of lymphatic endometritis, caused by epithelioid granuloma reaction after the death of the worm, visible epithelioid cells, foreign body giant cells and eosinophils. There are often chronic inflammatory reactions and lymphatic vessels around the lymphatic vessels. The skin and subcutaneous tissue in the elephanty area are thickened fibrosis, and small blood vessels and lymphatic vessels are dilated. The dermal papilla widens and the sweat glands shrink or disappear.

Skin filariasis prevention

1. The census and the early detection of patients and worms will be cured in time to ensure the health of the people and reduce and eliminate the source of infection. The census should target all residents over one year of age and require more than 95% of the residents to accept blood collection.

2. Strengthen publicity and prevent mosquitoes and mosquitoes.

3. Strengthen epidemiological surveillance of areas that have reached the level of basic elimination of filariasis. In the monitoring work, it should be noted that: 1 review and re-examine the original positive patients; re-investigate and repair the unexamined patients; strengthen the management of the floating population, find the patients, and treat them in time until they turn negative. 2 Strengthen the mosquito-borne surveillance of blood-positive households and find that infected mosquitoes, that is, focus on infected mosquitoes, expand blood tests and kill mosquitoes to surrounding people to remove epidemic spots and prevent further spread.

Complications of cutaneous filariasis Complications anemia

Patients can develop anemia.

Symptoms of skin filariasis Common symptoms Diarrhea fever Joint pain Inflammation chills Ascites Nodules Lymph node enlargement

The disease is more common in young adults, more common in men. After infection, there are often no symptoms, only insects. This asymptomatic patient contains a large amount of microfilaria in the peripheral blood, which is an important source of infection. Only some people may have clinical symptoms. The clinical symptoms vary depending on the location of the two silkworm parasites. Male worms are parasitic in the upper part of the upper and lower extremity lymph system, and the lower extremities are more common; the worms are more parasitic in the deep lymphatic system, and the lower limbs, scrotum and groin are more common. The clinical symptoms and the severity of the infection are closely related to the repeated infection and the state of the body's response. They are generally divided into two categories: early symptoms and late symptoms.

(I) Early symptoms Mainly caused by systemic and local allergic reactions and inflammatory reactions caused by adult and microfilariae metabolites, appearing several months after infection. Common symptoms are:

1, lymphangitis, lymphadenitis more common in one or both sides of the lower limbs, often a periodic episode, there are chills, fever, headache, joint pain and muscle soreness, lymph nodes in the groin or thigh Lymphangiitis, tenderness, localized skin erythema, burning sensation and tenderness, and sometimes urticaria-like damage.

2, spermatic inflammation, epididymitis or orchitis caused by adult parasitic lymphatic vessels in the scrotum, repeated attacks, fever, testicular and epididymal enlargement, spermatic cord with nodular mass, pain and tenderness, often in a few It subsided within a day and soon relapsed.

3, erysipelas-like dermatitis occurs in the lower part of the lower leg, local skin redness, nervousness, tenderness and burning sensation, the symptoms are similar to erysipelas, but the systemic symptoms are lighter than erysipelas.

(B), late symptoms After a long-term recurrent and continuous re-infection, there are some obstructive chronic inflammation, showing skin edema hypertrophy, fibrosis. The elephantiasis formed by lymphatic obstruction is a major feature of advanced blood filariasis. Because of the reflux disorder caused by obstruction of the lymphatic system, the lymphatic vessels below the obstruction site are dilated and even ruptured. If the deep lymphatic system in the femoral obstruction occurs, chyluria, chyle ascites, such as spermatic cord, testicular lymphatic obstruction, and testicular hydrocele. Such as superficial inguinal lymphatic obstruction, scrotal lymphedema or labia majora. Lymphatic edema of the lower extremity occurs in the lower extremity lymphedema or elephantiasis.

Examination of skin filariasis

Microfilament examination: the method is to take 3 drops of blood from the fingertips or earlobe at 12 o'clock before and after midnight, smear examination, chyluria or lymphatic effusion, sediment smear after centrifugation, if microfilaria is found, Can be diagnosed, but negative can not exclude the diagnosis.

Blood routine: In the acute phase, there are leukocytosis and significant increase of eosinophils, IgE is increased, serum anti-streptolysin "O" titer is often increased in the later stage, and patients may have anemia.

Lymph nodes, lymphangitis or granuloma biopsy can be seen in the fungus.

Biopsy if necessary.

Diagnosis and diagnosis of filariasis

diagnosis

In the filariasis epidemic area, if there are lymph nodes, lymphangitis, thickening of the spermatic cord or nodules, chyluria, elephantiasis, eosinophilia and other symptoms, it is necessary to consider the possibility of this disease. If the microfilaria is found in the peripheral blood, it can be diagnosed. After 10:00 pm, the peripheral blood is taken as a thick smear or a blood film to find the microfilaria, or it can be taken from the chyluria, chylorrhea or lymph by centrifugation. Microfilaria is often found in the body. In addition, intradermal test, serum antibody test, lymphangiography can assist in diagnosis. Pathological examination of nodular skin filariasis can help diagnose.

Differential diagnosis

The acute phase should be distinguished from bacterial lymphadenitis and elephantiasis, and the chronic phase should be differentiated from other silkworm infections.

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