subject: Threadworms transmission, clinical features and management [print this page] Threadworms transmission, clinical features and management
Infection with the intestinal nematode Enterobiusvermicularis causes pruritus ani. Children are mostoften affected, but adults can also become infected.
Transmission Autoinfection maintains the parasite in the host. Personto-person spread is the likely route of infection in childrenand other family members, or by handling pyjamas, sheetsor towels with adherent eggs.
Clinical features Intense pruritus ani is the usual symptom of this infectionand often disrupts sleep. When symptoms are presentthe worms may be seen on the perianal skin. In females vulvovaginitis and vaginal discharge may occur.
Diagnosis Diagnosis is made either by identifying a female wormobtained from the perianal skin or the faeces, or by findingeggs. The perianal skin should not be washed before theswab is taken. Eosinophilia does not occur.
Management A number of drugs are available and it is usual to treat thewhole family. Mebendazole (100 mg as a single dose, followed by a second dose 2 weeks later) is effective. Piperazinecitrate (65mg/kg to a maximum dose of 2.0g/day for 6days, repeated after 3 weeks) can be used. Pyrviniumpamoate (5mg of base/kg as a single dose) is also used.In addition to chemotherapy it is helpful to preventringer sucking and nail biting. The importance of handwashingafter going to the lavatory and before eatingshould be stressed. Occasionally one child is chronicallyafflicted by enterobiasis, and this causes both child andfamily great distress. This may occur in families that areparticularly careful about washing. Reassurance is neededthat this is not uncommon, and that enterobiasis isoccasionally difficult to treat. prevention can be done by cleaning.
