Threadworm.

 

Definition:

Threadworms are small, white worms which can infect the intestines. They are between 2mm and 13mm and most commonly affect children, although can be found in persons of any age. 

 

 

Causes:

Female threadworms lay eggs around the anus, which cause itching. Often this occurs during the night, so a person may not realise they are itching the anus. Eggs get stuck under fingernails and on fingers, which may result in them being swallowed or passed to another person. Eggs may also settle on bedding or clothing, or can even be wafted through the air to become part of the dust at home. This allows easy transmission between people, especially children, which ensures the life cycle of the worm can continue. Once the eggs are swallowed they hatch and grow into adults worms in the gut.

 

 

Presentation:

The most common complaint is of an itchy anus, which may become sore.

 

Threadworms may also be present in stools- they appear as white cotton-like threads.

 

A tape test may also be requested- before bathing in the morning a piece of clear tape should be pressed to the anus, which can be sent off to check for the presence of eggs under a microscope.

 

 

Differential Diagnosis:

It is always helpful to have a confimed presence of threadworm in the stool, or a tape test with eggs present. If the only symptom is an itchy anus it may be worth considering other causes such as dermatitis.

 

Threadworm is unlikely to be confused with other worms such as roundworm, as they are much smaller (human roundworms are around 30cm long)

 

 

Treatment:

All household members, even those not showing any signs of infection, should be treated at the same time,

as people can still pass on eggs without showing signs of having threadworm.

 

Most commonly, a tablet of mebendazole 100mg is taken, with a second tablet to be taken after 2 weeks if

reinfection is suspected. For example, Ovex Tablets. These tablets are only suitable for children aged over

2 and are not for use in pregnancy. It is critical that household hygiene measures are also undertaken to

eradicate the eggs.

 

 

Self Help Advice:

As a one off, all bed linen, clothing and cuddly toys should be washed. The house should be cleaned,

vaccummed and dusted, and any cloths thrown away after use.

 

Wear close fitting underwear at night to minimise itching around the anus, wash and change this everyday.

Immediately after waking, have a bath or wash the anus area to remove any eggs laid in the night,

 

Wash hands and scrub under nails in the mornings, after changing nappies, and before preparing or eating food.

 

Keep nails short and discourage children from biting or sucking fingers.

 

If possible avoid sharing towels and wash after use.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sample Question:

Mebendazole is the drug of choice for treating threadworm infections in patients over the age of 2 years. It is given as a single dose, but as reinfection is common, a patient may take another dose after how many days?

 

A 7 days

B 10 days

C 14 days

D 21 days

E 28 days

 

 

Answers to all sample questions can be found by following the link under the Test Yourself tab.