Pediatric emergency medicine trisk 2331 2331
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (99.81 KB, 1 trang )
Lymphatic filariasis may be diagnosed via microscopic detection of
microfilaria on blood smears obtained at night. In addition, adult worms or
microfilaria may be detected with skin biopsy, and ultrasonography can
sometimes be used to detect adult worms. Nocturnal microfilaria of W. bancrofti
and B. malayi may be provoked to enter the bloodstream during the day with a
one-time dose of diethylcarbamazine citrate (DEC). Blood examination should
be performed 30 to 60 minutes after administration of DEC. PCR and
immunologic testing are also available. The drug of choice for lymphatic
filariasis is DEC (2 mg/kg/dose three times daily after food for 12 days; there is
no maximum adult dose). Ivermectin (150 μg/kg; there is no maximum adult
dose) is effective against the microfilaria of W. bancrofti but has no effect on the
adult worm. Consequently, combination therapy with DEC-ivermectin or
ivermectin-albendazole is needed for suppression of microfilaremia. TPE is
treated with DEC for 12 to 21 days. DEC is no longer commercially available in
the United States but can be obtained through the CDC (404-718-4745).
Paradoxical worsening, including encephalopathy, can occur during treatment,
especially in patients with high organism burdens. Standard precautions exist for
isolation of patients with lymphatic filariasis. There is no human-to-human
transmission of microfilaria and adult worms with the exception of transfusion
with infected blood.
Onchocerciasis (river blindness) is caused by Onchocerca volvulus and
transmitted by Simulium blackflies. Approximately 18 million people worldwide
are infected, over 500,000 have severe visual disability. Clinical manifestations
may be dermatologic or ocular. Skin manifestations present as a pruritic rash
with multiple papules that may resolve spontaneously or continue to spread.
Painless, firm, mobile granulomas may develop in subcutaneous tissue, but
rarely cause morbidity. Ocular lesions involve both the anterior and posterior
segments. Anterior segment lesions result from an acute inflammatory reaction
around microfilariae and are reversible with therapy. Posterior segment lesions
involve the optic nerve and chorioretinitis and may result in blindness. Diagnosis
can be made clinically. Laboratory confirmation may be sought via PCR or
microscopic examination of skin snips for microfilariae. The diagnosis is
primarily clinical, as microfilariae may not be present in patients with
lymphedema. Treatment is with ivermectin in a single dose of 150 μg/kg (there
is no maximum adult dose). DEC can cause adverse ophthalmic reactions and is
contraindicated in onchocerciasis. Standard precautions should be used.
SEXUALLY TRANSMITTED INFECTIONS
