What is the recommended treatment and management for scabies, including medication regimen, application instructions, household precautions, and follow‑up care?

Scabies: Patient Information Guide

What is Scabies?

Scabies is a highly contagious skin infestation caused by the mite Sarcoptes scabiei that burrows into your skin, causing intense itching that typically worsens at night. 1, 2 The main symptom is severe pruritus (itching), and if this is your first infection, it may take several weeks before itching begins as your body develops sensitivity to the mites. 1 However, if you've had scabies before, itching can start within 24 hours of re-exposure. 1

How Do You Get Scabies?

• Transmission occurs primarily through direct, prolonged skin-to-skin contact. 3 In adults, scabies is frequently sexually transmitted, though in children it usually spreads through non-sexual contact. 1
• The mites can survive off the body for up to 48-72 hours at room temperature, so transmission through bedding and clothing is possible but less common. 1, 3

Recommended Treatment

First-Line Treatment Options

The preferred treatment is permethrin 5% cream, which is effective, safe, and less expensive than oral alternatives. 1 Here's how to use it:

• Apply the cream to all areas of your body from the neck down (including between fingers and toes, under nails, and in skin folds). 1
• Leave it on for 8-14 hours (typically apply before bed and wash off in the morning). 1
• Infants and young children should be treated with permethrin as the first choice. 1

Alternative Treatment: Oral Ivermectin

• Ivermectin 200 mcg/kg orally, repeated in 2 weeks is an alternative option. 1
• Take ivermectin with food to increase absorption and effectiveness. 1
• This option is particularly useful if you cannot tolerate topical treatments or have severe skin inflammation. 3
• Important caution: One study showed increased mortality in elderly, debilitated persons receiving ivermectin, though this hasn't been confirmed in subsequent reports. 1

Third-Line Option: Lindane

• Lindane should only be used if you cannot tolerate the recommended therapies or if they have failed due to potential toxicity including seizures and aplastic anemia. 1
• Never use lindane if you are pregnant, breastfeeding, have extensive dermatitis, are a child under 10 years old, or immediately after bathing. 1

Critical Application Instructions

Common Pitfalls to Avoid

• Treatment failure often occurs due to improper application of topical agents. 4 Ensure complete coverage of all skin surfaces from the neck down.
• Do not apply treatments immediately after a hot bath or shower, especially with lindane, as this increases absorption and toxicity risk. 1
• Keep fingernails closely trimmed to reduce injury from excessive scratching. 1

Household Precautions

All bedding, clothing, and towels must be decontaminated on the same day treatment begins. 1 Here's what to do:

• Machine-wash and machine-dry items using the hot cycle, or dry-clean them. 1
• Alternatively, remove items from body contact for at least 72 hours (the mites cannot survive longer than this off the body). 1, 3
• Fumigation of your living areas is NOT necessary. 1

Contact Management

All sexual partners and close household contacts within the previous month must be examined and treated simultaneously, even if they have no symptoms. 1, 5 This is critical because:

• Avoid all sexual contact until you and your partners have completed treatment, decontaminated bedding/clothing, and been re-evaluated. 1
• Failure to treat contacts simultaneously is a major cause of treatment failure and reinfection. 4, 6

Follow-Up Care

What to Expect After Treatment

• Itching and rash may persist for up to 2 weeks after successful treatment due to allergic reactions to dead mites. 1 This does NOT necessarily mean treatment failed.
• Seek re-evaluation if symptoms persist beyond 2 weeks. 1

When Re-Treatment is Needed

Re-treatment should be considered if: 1

• Live mites are still observed after 2 weeks
• Symptoms worsen or fail to improve
• New burrows appear
• You were re-exposed through untreated contacts

If re-treatment is necessary, use an alternative regimen (e.g., if permethrin was used first, switch to ivermectin). 1

Special Populations

Pregnancy and Breastfeeding

• Pregnant and lactating women should be treated with permethrin as the safest option. 1
• Ivermectin is classified as "human data suggest low risk" in pregnancy and is probably compatible with breastfeeding. 1
• Never use lindane during pregnancy due to associations with neural tube defects and mental retardation. 1

Infants and Young Children

• Permethrin is the treatment of choice for infants and young children. 1
• Children under 10 years should never receive lindane. 1

Crusted (Norwegian) Scabies

If you are immunocompromised, debilitated, or develop thick, scaly skin with minimal itching, you may have crusted scabies, which requires aggressive combination therapy: 1

• Topical permethrin 5% cream applied daily for 7 days, then twice weekly until cure 1
• PLUS oral ivermectin 200 mcg/kg on days 1,2,8,9, and 15 1
• Additional ivermectin doses on days 22 and 29 may be needed for severe cases. 1

Screening for Other Infections

You should be evaluated for other sexually transmitted infections, including HIV, especially if scabies was sexually acquired. 1

Key Takeaways for Success

• Treat yourself and all contacts simultaneously on the same day 4, 6
• Apply topical treatments to your entire body from the neck down 1
• Decontaminate all bedding and clothing on treatment day 1
• Expect itching to persist for up to 2 weeks after successful treatment 1
• Seek re-evaluation only if symptoms persist beyond 2 weeks or worsen 1