Enterobiasis - Nursing Care Planning and Management

Enterobiasis (pinworm, seatworm, or threadworm) is a highly contagious infestation by the nematode Enterobius vermicularis, most common in school-age children and spread by ingesting or inhaling eggs. It is not a marker of poor hygiene, and it runs in family clusters, so treatment means treating the whole household, not just the child. The defining problem is intense nighttime perianal itching, and reinfection is the rule without good hand and nail hygiene.

What is Enterobiasis?

Enterobius vermicularis is a small nematode, with an estimated 40 million infected individuals in the United States. The pinworm is a white thread-like worm that invades the cecum and may enter the appendix. The female averages 10 mm x 0.7 mm; males are smaller. Articles contaminated with pinworm eggs spread the worms person to person. All socioeconomic levels are affected, and infestation often occurs in family clusters; it does not equate with poor home sanitation, an important point when discussing therapy.

Pathophysiology

The worm's life cycle is 6 to 8 weeks, after which reinfestation commonly occurs without treatment. E. vermicularis is an obligate parasite, and humans are the only natural host. Fecal-oral contamination through hand-mouth contact or fomites (toys, clothes) are the common routes. After ingestion, eggs usually hatch in the duodenum within 6 hours. Worms mature in as little as 2 weeks and live about 2 months. Adult worms normally inhabit the terminal ileum, cecum, vermiform appendix, and proximal ascending colon, living free in the intestinal lumen. After copulation the female migrates to the rectum and, if not expelled during defecation, moves to the perineum (often at night) where she releases an average of 11,000 eggs. Eggs become infectious within 6-8 hours and, under optimal conditions, stay infectious in the environment for as long as 3 weeks.

Statistics and Incidences

Incidence is highest in school-age children and next highest in preschoolers. Prevalence is about 5-15% in the general population, though it has declined in recent years and is probably higher in institutionalized individuals; humans are the only known host. Infestation rates rise with population density and personal habits such as thumb sucking. E. vermicularis occurs worldwide, with prevalence varying by country. A study of rural coastal Tanzania found Enterobius vermicularis in 4.2% of infants, 16.7% of preschool-aged children, and 26.3% of school-aged children. Secondary bacterial skin infection can develop from vigorous scratching to relieve pruritus. Those most likely to be infected are children younger than 18 years, caregivers of infected children, and institutionalized people, where prevalence can reach 50%.

Clinical Manifestations

Intense perianal itching is the primary symptom, especially at night when the female worm leaves the anus to deposit ova. Patients often show excoriation or erythema of the perineum, vulvae, or both, though infestation can occur without them. Abdominal pain may be severe and can mimic acute appendicitis. Visual sighting of a worm by a reliable source (such as a parent) is usually accepted as evidence of infestation and grounds for treatment.

Assessment and Diagnostic Findings

The usual method is the cellophane tape test, performed in the early morning just before or as the child wakens to capture eggs from around the anus; the tape is then examined microscopically in the laboratory.

Medical Management

Thorough, regular handwashing effectively prevents transmission. Changing habits such as thumb-sucking or nail-biting reduces reinfection, and the child should bathe regularly and change underclothing daily. Teach caregivers to keep the child's fingernails short and clean.

Pharmacologic Management

Drug therapy with pyrantel, mebendazole, or albendazole is the current standard. Mebendazole is not currently available in the United States; pyrantel pamoate or albendazole (not currently FDA-approved for this use) are recommended alternatives, with a second dose given 2 weeks after the initial dose. Parasite biochemical pathways differ from the human host, so toxicity is directed at the parasite, egg, or larvae, and the mechanism of action varies within the drug class. Anal albendazole may help with the symptoms of pruritus ani.

Nursing Management

Nursing Assessment

Patients are often asymptomatic, with worms found incidentally in the perineal region; when symptomatic, pruritus ani and pruritus vulvae are the common presenting complaints. On exam, worms can be found in stool or on the perineum before morning bathing.

Nursing Diagnosis

• Risk for impaired skin integrity related to intense perianal scratching.
• Acute pain related to smooth muscle spasm secondary to migration of parasites.
• Imbalanced nutrition, less than body requirements, related to anorexia and vomiting.
• Hyperthermia related to decreased circulation secondary to dehydration.

Nursing Care Planning and Goals

• Reduce discomfort from perianal itching.
• Diminish pain to a tolerable level.
• Regain adequate nutrition.
• Reduce or eliminate any rise in temperature.

Nursing Interventions

Give medications as ordered. Drug therapy with pyrantel, mebendazole, or albendazole destroys the parasite, and effective eradication requires treating the patient's family or household members.

Inform the patient of pyrantel side effects. Stool may turn bright red, and the drug may cause vomiting. The tablet form is coated with aspirin and should not be given to aspirin-sensitive patients.

Improve skin integrity. An antipruritic ointment or albendazole can help control scratching, and trimming the patient's fingernails prevents excoriation.

Diminish pain. Prescribe an anthelmintic medication.

Improve hygiene. Avoid scratching the area and nail-biting, both causes of autoinfection, and do thorough handwashing before and after meals. Tell the family not to shake bed linens, to avoid aerosolizing eggs.

Reduce temperature. Give antipyretics as prescribed, and tepid sponge baths may help. Inform the patient and family about transmission and the hygiene measures (handwashing, short fingernails, daily laundering of bedding and underwear) that prevent reinfection.

Evaluation

Goals are met when perianal itching eases, pain drops to a tolerable level, nutrition is regained, and any temperature rise is reduced.

Documentation Guidelines

• Individual findings: contributing factors, interactions, the nature of social exchanges, and specifics of behavior.
• Cultural and religious beliefs and expectations.
• Plan of care.
• Teaching plan.
• Responses to interventions, teaching, and actions performed.
• Attainment or progress toward the desired outcome.