Threadworms

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Threadworms, also known as pinworms, are small, thin, white worms that infect the intestines of humans. They are a common type of intestinal worm infection in the UK, particularly among children.

Aetiology

Threadworms are caused by the nematode Enterobius vermicularis. The infection is spread through the ingestion of threadworm eggs, which can survive on surfaces, clothing, and bedding for up to two weeks.

Pathophysiology

The pathophysiology of threadworm infection involves:

• Ingestion of threadworm eggs, which hatch in the small intestine.
• The larvae mature into adult worms and migrate to the large intestine.
• Female worms travel to the perianal area, usually at night, to lay eggs, causing intense itching.
• Scratching the itchy area can lead to contamination of fingers and under the nails, which can then spread the eggs to other surfaces or directly to other individuals.

Risk Factors

• Young age (particularly school-aged children)
• Living in crowded conditions
• Poor hygiene practices
• Close contact with an infected person

Signs and Symptoms

The signs and symptoms of threadworm infection include:

• Intense itching around the anus, especially at night
• Disturbed sleep due to itching
• Visible threadworms in the stool or around the anus
• Loss of appetite
• Weight loss
• Irritability

Investigations

Specific investigations to diagnose threadworms include:

• Sticky tape test: Pressing clear tape around the anus to collect eggs, which are then examined under a microscope.
• Visual inspection: Looking for adult worms around the anus, particularly at night when the female worms lay eggs.

Management

Primary Care Management

• Anthelmintic medication: Over-the-counter treatments such as mebendazole are effective in killing threadworms.
• Hygiene measures: Implementing strict hygiene measures to prevent re-infection and spread, including:
  • Washing hands thoroughly with soap and water before eating and after using the toilet.
  • Keeping fingernails short and clean.
  • Changing and washing underwear, nightwear, and bedding daily during treatment.
  • Cleaning household surfaces, especially in the bathroom and kitchen.

Specialist Management

• Referral to a specialist: Usually not required for uncomplicated cases of threadworm infection.
• Recurrent or severe cases: May require further investigation and treatment by a specialist, particularly if standard treatments fail or complications arise.

References

1. NHS (2024) Threadworms. Available at: https://www.nhs.uk/conditions/threadworms/ (Accessed: 24 June 2024).
2. Centers for Disease Control and Prevention (2024) Pinworm Infection. Available at: https://www.cdc.gov/parasites/pinworm/index.html (Accessed: 24 June 2024).
3. World Health Organization (2024) Intestinal Worms. Available at: https://www.who.int/health-topics/intestinal-worms (Accessed: 24 June 2024).
4. British Medical Journal (2024) Threadworms: clinical features, diagnosis, and management. Available at: https://www.bmj.com/content/350/bmj.g8895 (Accessed: 24 June 2024).

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