Scabies | Signs And Symptoms Of Scabies | How To Spread Scabies Infection | Scabies Treatment And Prevention Measures

 Scabies is an extremely contagious dermatological condition resulting from the infestation of the Sarcoptes scabiei mite. These tiny mites penetrate the skin, leading to severe itching and a rash resembling pimples. The itching often intensifies during the night and can reach a debilitating level.

The manifestation of scabies can vary based on factors such as severity, individual immune response, and the specific circumstances of the affected individual. The primary classifications of scabies include:

Types And Symptoms Of Scabies 

1. Typical (Classic) Scabies

Most common form of scabies, caused by Sarcoptes scabiei var. hominis.

Symptoms:

• Intense itching, especially at night.

• Rash with small red bumps, blisters, or burrow tracks.

• Commonly affects areas like fingers, wrists, elbows, armpits, waistline, genitals, buttocks, and breasts.

It spreads mainly through direct skin contact and occasionally through contaminated objects.

2. Crusted (Norwegian) Scabies

A severe and highly contagious form, mostly seen in immunocompromised individuals (HIV/AIDS, cancer, elderly, malnourished).

Symptoms:

Thick, crusty, scaly skin with thousands of mites inside.

Less itching than classic scabies, despite a heavy infestation.

Affects large areas, including the scalp, hands, feet, and nails.

Highly contagious through skin contact and contaminated objects (bedding, clothing).

3. Nodular Scabies

A chronic form of scabies where itchy nodules develop due to a prolonged immune response to mite infestation.

Symptoms:

Firm, red-brown nodules that can persist for months after treatment.

Common in areas like the genitals, armpits, and buttocks.

More frequent in children and people with strong immune responses.

4. Infantile (Pediatric) Scabies

Seen in infants and young children, affecting areas not commonly involved in adults.

Symptoms:

Severe itching and irritability.

Red rashes, blisters, and burrows on the face, scalp, palms, and soles.

More rapid spread due to frequent skin-to-skin contact with caregivers.

5. Atypical (Invisible) Scabies

A rare form with few or no visible symptoms, making diagnosis difficult.

Symptoms:

Mild itching, often mistaken for eczema or an allergic reaction.

No clear burrows or rash.

More common in immunocompromised individuals.

6. Animal Scabies (Mange in Humans)

Caused by mites from animals (e.g., dogs, cats, livestock). Cannot reproduce in human skin, so symptoms are temporary.

Symptoms:

Itchy red bumps but no burrows.

Symptoms disappear in a few weeks once exposure stops.

 Causes & Transmission Of Scabies 

These microscopic parasites burrow into the skin, lay eggs, and trigger an intense allergic reaction, leading to severe itching and rash.

Causes of Scabies

1. The Sarcoptes Scabiei Mite

• Lifecycle: The female mite burrows into the skin, lays eggs, and the larvae hatch within 3–4 days. These larvae grow into adults and spread across the body, continuing the infestation.

• Survival: Mites can survive up to 1–2 months on a human host but only 2–3 days on clothing, bedding, or furniture.

2. Immune System Response

The itching and rash in scabies are due to an allergic reaction to the mites, their eggs, and their waste.

Symptoms usually appear 2–6 weeks after initial infestation but within days upon reinfection.

Transmission of Scabies

Scabies spreads through direct and indirect contact:

1. Direct Skin-to-Skin Contact (Most Common)

• Prolonged contact (e.g., holding hands, hugging, sexual contact) is the primary way scabies spreads.

• It is common in households, dormitories, schools, prisons, and nursing homes due to close living conditions.

• Quick touches like handshakes or casual contact usually don’t transmit scabies.

2. Indirect Transmission (Less Common)

• Fomites: Scabies mites can survive outside the body for a short time on:
• Bedding, clothing, towels, upholstery, furniture
• Shared personal items (e.g., hairbrushes, gloves, stuffed animals)

Indirect transmission is more common with crusted (Norwegian) scabies, where thousands of mites are present.

3. High-Risk Groups

• Children & Elderly: More prone due to close contact and weaker immunity.
• Immunocompromised Individuals: People with HIV, cancer, organ transplants, or autoimmune diseases may develop severe, widespread scabies (crusted scabies).
• People in Crowded Living Conditions: Nursing homes, military barracks, prisons, homeless shelters.
• Healthcare Workers & Caregivers: Due to close contact with infected individuals.

How Long Is Scabies Contagious?

1. Before Symptoms Appear: A person can unknowingly spread scabies for 2–6 weeks before showing symptoms.
2. After Treatment Begins: People are still contagious for about 24–48 hours after the first treatment.

Treatment for Scabies

Prescription creams/lotions:

• Permethrin cream (5%) – First-line treatmentL
• indane lotion – Used when other treatments fail (not recommended for pregnant women, children, or elderly)
• Clotamiton (Eurax) – Less effective, used in some cases 
• Sulfur ointment (5-10%) – Alternative for infants and pregnant women.

Prevention Strategies

• Avoid prolonged skin contact with infected individuals.
• Wash clothes, bedding, and towels in hot water (at least 50°C/122°F) and dry on high heat.
• Vacuum and clean furniture, carpets, and shared spaces.
• Treat all household members and close contacts simultaneously, even if they have no symptoms.