Scabies

Scabies: Symptoms, Causes, Types, Diagnosis, and Treatments

Scabies is a highly contagious skin condition caused by the microscopic mite Sarcoptes scabiei. Despite being a common problem worldwide, it often goes unrecognized, leading to prolonged discomfort and spreading among close contacts. This detailed guide will explore everything you need to know about scabies—from its symptoms and causes to its types, diagnosis, and effective treatments.

What is Scabies?

Scabies is a parasitic infestation of the skin caused by the Sarcoptes scabiei mite. These tiny mites burrow into the upper layer of the skin to live and lay eggs. The body’s immune response to the mite, its eggs, and waste products results in intense itching and a characteristic rash.

Scabies affects people of all ages and socioeconomic backgrounds but is more common in crowded living conditions and places with poor hygiene. It spreads easily through prolonged skin-to-skin contact, making families, schools, nursing homes, and prisons vulnerable to outbreaks.

Symptoms of Scabies

The hallmark symptom of scabies is intense itching, which often worsens at night. This itchiness results from an allergic reaction to the mite and its byproducts. Other symptoms include:

Itching

• Severe itching, especially at night, disrupting sleep.
• Itching may persist for weeks after treatment until the body clears the allergic reaction.

Rash

• Small red bumps or blisters appear on the skin.
• Rash often looks like tiny pimples or hives and may become infected due to scratching.

Burrows

• Thin, grayish or skin-colored lines called burrows.
• These are tunnels created by the female mite as she digs into the skin.
• Burrows are usually 2 to 15 mm long and best seen in areas like the webbing between fingers, wrists, elbows, armpits, waistline, and genital area.

Sores and Crusts

• Scratching can cause skin breaks leading to sores, secondary infections, and thick crusts.
• Crusted scabies, a severe form, causes thick, scaly patches that harbor thousands of mites.

Common Areas Affected

• Between fingers and toes
• Wrists and elbows
• Armpits
• Waist and belt line
• Genital region
• Around nipples (especially in women)
• Buttocks and knees
• Scalp and face (especially in infants and elderly)

In Infants and Young Children

• Rash may appear on the head, face, neck, palms, and soles.
• Babies may be irritable and cry excessively due to itching.

Causes of Scabies

Scabies is caused by infestation with the Sarcoptes scabiei mite, which is a microscopic, eight-legged parasite.

How Scabies Spreads

The mites spread primarily through prolonged skin-to-skin contact with an infested person. Casual contact, such as shaking hands briefly or touching a doorknob, generally does not transmit scabies.

Other transmission routes include:

• Sharing bedding, towels, or clothing with an infested person.
• Sexual contact.
• Close contact in crowded environments such as nursing homes, prisons, daycare centers, or refugee camps.

Life Cycle of the Mite

• Female mites burrow into the skin, laying 2–3 eggs per day.
• Eggs hatch into larvae within 3–4 days.
• Larvae mature into adult mites in 1–2 weeks.
• Mites live for 1 to 2 months on the human body but cannot survive more than 2–3 days off the skin.

Risk Factors for Scabies

• Living in crowded or unsanitary conditions.
• Having a weakened immune system.
• Close contact with an infested person.
• Sexual activity.
• Institutional living (nursing homes, prisons).
• Traveling to or living in endemic areas.

Types of Scabies

While typical scabies is most common, there are several types and variants of this infestation:

Classic Scabies

• The most common form.
• Characterized by intense itching and a rash with burrows.
• Usually involves 10-15 mites on the body.

Crusted Scabies (Norwegian Scabies)

• Severe, highly contagious form seen in immunocompromised people, elderly, and disabled individuals.
• Characterized by thick crusts of skin containing thousands to millions of mites.
• Crusts can be widespread and may look like psoriasis or eczema.
• Requires aggressive treatment.

Nodular Scabies

• Occurs when itchy nodules develop, especially on the genital area, armpits, and groin.
• Nodules are inflamed, reddish-brown bumps that can persist for weeks after treatment.

Scabies in Infants and Children

• Rash may involve the face, scalp, palms, and soles.
• Symptoms can be more generalized.
• Itching can cause irritability and feeding problems.

Animal Scabies (Sarcoptic Mange)

• Caused by mites from animals such as dogs or cats.
• Usually transient and does not produce a full infestation in humans.

Diagnosis of Scabies

Diagnosing scabies requires a combination of clinical examination and sometimes laboratory tests.

Clinical Examination

• Doctors examine characteristic skin lesions.
• Identification of burrows is a key diagnostic feature.
• Distribution of rash in classic sites aids diagnosis.

Dermoscopy

• A handheld magnifying device allows visualization of mites or burrows.
• Mites appear as dark triangular structures at the end of burrows.

Skin Scraping and Microscopy

• The doctor gently scrapes the skin lesion and examines the sample under a microscope.
• The presence of mites, eggs, or fecal pellets confirms diagnosis.

Adhesive Tape Test

• Sticky tape is applied to suspicious skin and then examined microscopically.

linical Criteria

• Sometimes diagnosis is based on symptoms, history of contact, and typical rash distribution.

When to See a Doctor

• Persistent itching and rash despite usual remedies.
• Close contact with someone diagnosed with scabies.
• Appearance of crusted lesions or nodules.

Treatments for Scabies

Effective treatment aims to eradicate the mites and relieve symptoms. Since scabies is contagious, treatment should include close contacts and environmental decontamination.

Topical Medications

The most common treatment for scabies is prescription topical scabicides, including:

Permethrin Cream (5%)

• First-line treatment.
• Applied over the entire body from neck down and left on for 8-14 hours.
• Usually requires one application; sometimes repeated after 1 week.
• Safe for adults, children over 2 months, and pregnant women.

Lindane Lotion

• Alternative when permethrin is unavailable.
• Applied for 8 hours.
• Use is limited due to potential neurotoxicity, especially in infants, elderly, and pregnant women.

Crotamiton Cream or Lotion

• Applied once daily for 2-5 days.
• Less effective than permethrin; often used in combination.

Sulfur Ointment (5-10%)

• Safe in infants and pregnant women.
• Requires nightly application for 3 consecutive nights.
• Has a strong odor and can be messy.

Oral Medications

Ivermectin

• Oral antiparasitic agent.
• Used in crusted scabies or when topical therapy fails.
• Given as a single dose, repeated after 7-14 days.
• Not approved for children under 15 kg or pregnant women but used off-label when necessary.

Symptomatic Treatment

• Oral antihistamines or corticosteroids to reduce itching.
• Antibiotics if secondary bacterial infections develop.

Treating Close Contacts

• All household members and sexual partners should be treated simultaneously, even if asymptomatic.

Environmental Cleaning

• Wash all bedding, clothing, and towels used within 3 days before treatment in hot water.
• Items that cannot be washed should be sealed in plastic bags for 72 hours.
• Vacuum carpets and furniture.

Prevention of Scabies

• Avoid direct skin contact with someone diagnosed with scabies.
• Avoid sharing bedding, towels, or clothing with others.
• Maintain good personal hygiene.
• Seek prompt treatment if symptoms develop.
• Inform close contacts and ensure they are treated simultaneously.

Complications of Untreated Scabies

If left untreated, scabies can lead to:

• Secondary bacterial infections (impetigo, cellulitis).
• Post-scabies eczema.
• Crusted scabies, which can be life-threatening.
• Scabies outbreaks in institutional settings.
• Persistent itching and sleep disturbance affecting quality of life.

Scabies FAQs

Q: How long does scabies last?
A: Without treatment, scabies can persist indefinitely. With treatment, symptoms typically improve within 1-2 weeks, but itching may continue for several weeks due to allergic reactions.

Q: Can pets get scabies?
A: Pets can get a related mite infestation called mange, but the human scabies mite is species-specific. Animal mites usually do not cause full infestations in humans.

Q: Is scabies contagious?
A: Yes, it spreads easily through prolonged skin contact.

Q: Can I get scabies more than once?
A: Yes, previous infestation does not confer immunity.

Conclusion

Scabies is a common, contagious skin condition caused by the Sarcoptes scabiei mite. Recognizing the symptoms—intense itching, rash, and burrows—is key to early diagnosis and treatment. With effective topical or oral medications and appropriate environmental measures, scabies can be cured completely. Early treatment of all close contacts helps prevent reinfestation and outbreaks.

If you or someone close to you has persistent itching and a suspicious rash, especially in typical areas, consult a healthcare professional promptly. Proper diagnosis and treatment can restore comfort and prevent the spread of this uncomfortable condition.

Frequently Asked Questions (FAQs) About Scabies

For more details keep visiting our Website & Facebook Page.