Scabies - What You Need to Know

Scabies

Introduction to Scabies
- Scabies Definition: A highly contagious skin infestation caused by Sarcoptes scabiei var. hominis.
- Primary Symptom: Pruritic rash due to delayed hypersensitivity reaction.
- Importance of Treatment: Prevents transmission, reduces morbidity, and avoids complications like cellulitis and rheumatic fever.

Transmission and Vulnerable Populations
- Transmission Methods:
- Prolonged skin-to-skin contact (e.g., household members, sexual partners).
- Fomites (clothing, furnishings) in severe crusted scabies cases.
- Vulnerable Groups:
- Children, older people, immunocompromised individuals.
- Common in low socioeconomic areas and crowded environments.
- Key Note: Not related to hygiene but influenced by population density and close-contact settings.

Types of Scabies
- Classic Scabies:
- Most common form; 5–15 mites.
- Rash starts on palms, soles, fingers, toes, then spreads.
- Nodular Scabies:
- Chronic form with inflammatory nodules in skin folds/genital areas.
- Nodules may persist after treatment.
- Crusted Scabies:
- Hyper-infestation with thousands to millions of mites.
- Thick, crusted plaques; more contagious.
- 50% of patients do not experience pruritus.

Scabies Mite Life Cycle
- Female mite burrows into skin, lays 2–3 eggs/day for up to 6 weeks.
- Larvae mature into adults in 10–13 days.
- Mites survive outside the human host for only about 3 days.

Diagnosis
- Classic Scabies:
- Clinical diagnosis based on burrows, rash, pruritus, and history.
- Burrows appear as thin, irregular, brown-grey lines.
- Confirmatory Tests:
- Ink test or dermatoscopy to visualize mites.
- Microscopy of skin scrapings (especially for crusted scabies or outbreaks).
- Treatment Decision: Often initiated without microscopic confirmation.

Symptoms
- Pruritus:
- Worsens after hot baths or at night.
- Starts in acral distribution (hands, feet) before spreading.
- Rash Characteristics:
- Small erythematous papules with hemorrhagic crusts.
- Common areas: trunk, limbs, wrists, interdigital spaces.
- Nodules:
- Persistent, 0.5–1 cm in diameter, found in groin, genitalia, buttocks, axillary folds.

Treatment
- First-Line Treatment:
- Topical permethrin 5% cream/lotion applied to entire body.
- Pay attention to webbing between fingers/toes and under nails.
- Wash off after 8–12 hours; repeat after 7–10 days.
- Additional Treatments:
- Oral ivermectin for crusted scabies.
- All close contacts should also be treated.

Post-Treatment Management
- Persistent Pruritus:
- May last several weeks after successful treatment.
- Managed with topical anti-pruritics (e.g., mild corticosteroids, crotamiton).
- Warning Signs:
- Pruritus lasting more than 6 weeks may indicate inadequate treatment or alternative diagnosis.
- Secondary Infections:
- Excessive scratching can cause bacterial infections requiring oral antibiotics.

Transmission Reduction
- Patient Instructions:
- Avoid direct contact with others for at least 8 hours post-treatment.
- Household Measures:
- Assess and treat all household members/close contacts within the last 30 days.
- Hot launder bedding, clothing, towels; vacuum carpets and upholstery.

Crusted Scabies Specifics
- Treatment Approach:
- Oral ivermectin (200 µg/kg, rounded to nearest 3 mg), repeated weekly until no burrows detected.
- Combined with topical permethrin.
- Adjunct Therapy:
- Salicylic acid (5–10%) in cetomacrogol aqueous cream with glycerol to reduce crusting and enhance permethrin absorption.

[Vodkazlo]

I use vinegar mixed with soda. I add a little water 2-3 cups. Then I pour the mixture into an empty bottle of antiseptic. I spray it on the floor, on the baseboards, on the bed every day once a day.

[jackcfchong]

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