Scabies Nursing Management and Care Plan

Scabies is intensely itchy, highly contagious, and easy to miss, which is exactly how it spreads through schools, hospitals, prisons, and nursing homes. Treat the patient and every close contact at the same time, decontaminate bedding and clothing, and warn people that itching can persist after the mites are dead. Miss the contacts and you will be treating the same infestation again in three weeks.

What Is Scabies?

Human scabies is caused by infestation of the skin with the human itch mite Sarcoptes scabiei var. hominis. The microscopic mite burrows into the upper layer of skin, where it lives and lays eggs. It stays common mostly because of diagnostic difficulty, inadequate treatment of patients and their contacts, and poor environmental control. As a clinical imitator, its range of skin findings often delays diagnosis. The term "7-year itch" was first used for persistent, undiagnosed scabies infestations.

Pathophysiology

Transmission is predominantly through direct skin-to-skin contact, which is why scabies has been considered a sexually transmitted disease.

The female S scabiei var hominis mite lays 60-90 eggs over her 30-day lifespan, though less than 10% of eggs become mature mites. Eggs incubate and hatch in 3-4 days, and 90% of the hatched mites die. Larvae (3 pairs of legs) migrate to the skin surface and burrow into the intact stratum corneum to make short molting pouches over 3-4 days. Larvae molt into nymphs (4 pairs of legs), which molt again before becoming adults. Mating happens once; the female is then fertile for the rest of her life and the male dies soon after. Using proteolytic enzymes to dissolve the epidermal stratum corneum, the female makes a serpentine burrow, laying eggs as she lengthens it, and survives 1-2 months. Impregnated females transmit person to person through direct or indirect skin contact.

Types

Classic scabies. Typically 10-15 mites (range, 3-50) live on the host. Little evidence of infection shows during the first month (range, 2-6 wk), but after 4 weeks and with later infections, a delayed type IV hypersensitivity reaction to the mites, eggs, and scybala (feces) develops.

Crusted scabies. Crusted, or Norwegian, scabies (named for the first description from Norway in the mid-1800s) is distinctive and highly contagious. Hundreds to millions of mites infest the host, who is usually immunocompromised, elderly, or physically or mentally disabled.

Nodular scabies. Nodules occur in 7-10% of patients, particularly young children. In neonates unable to scratch, pinkish-brown nodules 2-20 mm in diameter may develop.

Causes

Human scabies is caused by the host-specific mite Sarcoptes scabiei var. hominis, an obligate human parasite.

Scabies in adults is frequently sexually acquired. It passes easily to household members, and childcare facilities are a common site of infestation. Crowded conditions with close body and skin contact, including poor housing, let it spread.

Statistics and Incidences

An estimated 200 million people are affected by scabies at any given time, with prevalence rates ranging from 0.2% to 71%.

A survey of children in a welfare home in Pulau Pinang, Malaysia found the infestation rate highest among children aged 10-12 years, more common in boys (50%) than girls (16%), with an overall prevalence rate of 31%. Scabies is endemic in many tropical and subtropical regions and is one of the 6 major epidermal parasitic skin diseases (EPSD) prevalent in resource-poor populations, as reported in the Bulletin of the World Health Organization in February 2009. Prevalence is extremely high in aboriginal tribes in Australia, Africa, South America, and other developing regions. The World Health Organization reports a prevalence rate of 5-10% in children in resource-poor tropical countries.

Clinical Manifestations

On first infestation, symptoms usually take up to two months (2-6 weeks) to appear, but an infested person can still spread scabies during that time without symptoms.

Skin rash and itching come from sensitization (an allergic-type reaction) to the parasite's proteins and feces. Severe itching, especially at night, is the earliest and most common symptom. A pimple-like (papular) itchy scabies rash is also common. Tiny burrows, caused by the female mite tunneling just under the surface, appear as raised, crooked (serpiginous) grayish-white or skin-colored lines; burrows are a pathognomonic sign representing the intraepidermal tunnel the moving female creates.

Assessment and Diagnostic Findings

Diagnosis is often clinical in a patient with a pruritic rash and characteristic linear burrows.

Burrow ink test. Rub a washable felt-tip marker across the suspected site and remove the ink with an alcohol wipe; over a burrow, the ink penetrates the stratum corneum and outlines the site. This is especially useful in children and people with few burrows.

Tetracycline. Topical tetracycline solution is an alternative; after applying and removing excess with alcohol, examine the burrow under a Wood light, where remaining tetracycline fluoresces greenish. It is preferred because the solution is colorless and large skin areas can be examined.

Skin scraping. Definitive testing identifies mites, eggs, eggshell fragments, or scybala by placing a drop of mineral oil over the burrow and scraping longitudinally and laterally with a scalpel blade.

Adhesive tape test. Apply tape strips to suspected burrows, pull off rapidly, transfer to microscope slides, and examine. It is easy to perform with high positive and negative predictive values, making it a good screening test.

Medical Management

Treatment is a scabicidal agent (permethrin, lindane, or ivermectin) plus an antimicrobial if a secondary infection has developed.

Patients should avoid skin-to-skin contact and may return to school or work 24 hours after the first treatment. Decontaminate bedding, clothing, and towels used by infested persons or their household, sexual, and close contacts during the three days before treatment by washing in hot water and drying in a hot dryer, dry-cleaning, or sealing in a plastic bag for at least 72 hours.

Pharmacologic Management

The mainstay is topical scabicidal agents, with a repeat application in 7 days.

Topical options include permethrin cream (drug of choice), lindane, benzyl benzoate, crotamiton lotion and cream, sulfur, topical ivermectin, tea tree oil, or oil from the leaves of Lippia multiflora Moldenke, a West African savanna shrub. Oral options include ivermectin, though it is not FDA-approved for scabies. Topical antibiotics treat secondarily infected lesions, and topical corticosteroids help control the intense pruritus.

Nursing Management

Nursing Assessment

History. Patient history reliably suggests scabies. Lesion distribution, intractable pruritus worse at night, and scabies symptoms in close contacts (including multiple family members) should put scabies at the top of the differential.

Physical exam. Findings include primary lesions (small papules, vesicles, and burrows, the first manifestation) and secondary lesions from rubbing and scratching, which may be the only visible sign.

Nursing Diagnosis

Based on assessment, the major diagnoses are: Risk for infection related to tissue damage; Impaired skin integrity related to edema; Acute pain related to biological agents; and Disturbed sleep pattern related to itchiness and pain of lesions.

Nursing Care Planning and Goals

The patient stays free of infection (normal vital signs, no signs or symptoms of infection), and the patient and community understand the plan to heal tissue and prevent injury and can describe measures to protect and heal the tissue, including wound care. The patient describes satisfactory pain control at a level less than 3 to 4 on a 0 to 10 scale.

Nursing Interventions

Prevent infection. Wash hands and teach the patient and significant other to wash hands before contact and between procedures. Encourage fluid intake of 2,000 to 3,000 mL of water per day unless contraindicated. Teach the purpose and technique for maintaining isolation. If infection occurs, teach the patient to take the full course of antibiotics even if symptoms improve or disappear.

Restore skin integrity. Monitor the skin around the wound, and note skin-care practices, the cleansing agents used, water temperature, and cleansing frequency. Tell the patient to avoid rubbing and scratching, provide gloves or clip the nails if needed, and teach proper wound care including hand washing, cleansing, dressing changes, and applying topical medications.

Relieve pain. Acknowledge reports of pain immediately, provide rest periods for relief, sleep, and relaxation, give analgesics as ordered while checking effectiveness and adverse effects, and determine the appropriate pain relief method.

Evaluation

Goals are met when the patient stays free of infection (normal vital signs, no signs or symptoms of infection), the patient and family understand and can describe measures to heal and protect the tissue including wound care, and the patient reports satisfactory pain control at a level less than 3 to 4 on a 0 to 10 scale.

Documentation Guidelines

Document individual findings and behaviors, cultural and religious beliefs and expectations, the plan of care, the teaching plan, responses to interventions and teaching, and progress toward outcomes.

Key Points

The microscopic scabies mite burrows into the upper skin layer, where it lives and lays eggs. Transmission is predominantly through direct skin-to-skin contact, so scabies has been considered a sexually transmitted disease. In classic scabies, typically 10-15 mites (range, 3-50) live on the host; in crusted or Norwegian scabies, hundreds to millions of mites infest an immunocompromised, elderly, or disabled host; and in nodular scabies, nodules occur in 7-10% of patients, particularly young children. Human scabies is caused by the host-specific mite S. scabiei hominis, an obligate human parasite. An estimated 200 million people are affected at any time, with prevalence ranging from 0.2% to 71%. On first infestation, symptoms take up to two months (2-6 weeks) to appear. Symptoms include skin rash, pruritus, and burrows. Diagnosis is often clinical in a patient with a pruritic rash and characteristic linear burrows. Treatment is a scabicidal agent (permethrin, lindane, or ivermectin) plus an antimicrobial if a secondary infection has developed.