Scabies Symptoms: From Itching to Crusted Skin

Scabies Symptoms, Causes, Risk Factors & Medical Care 

Scabies is a contagious skin condition caused by mites burrowing into the skin, leading to intense itching, rashes, and skin discomfort. Recognising scabies symptoms early is essential to avoid complications such as infections or sleep disturbances. Prompt medical care and hygiene practices can help manage and prevent its spread effectively.

Introduction

Scabies is a highly contagious skin infestation caused by the eight-legged mite Sarcoptes scabiei var. hominis, which burrows into the upper layer of the skin. These mites lay eggs, triggering an allergic reaction that leads to intense itching and a rash. While scabies are not life-threatening, they can cause severe discomfort, skin soreness, and even secondary infections if left untreated.

The condition spreads quickly through close contact, but it is manageable with prompt diagnosis and effective treatment using topical creams or oral medications.

Is Scabies a Growing Health Concern?

Scabies is a significant global public health issue, particularly in crowded, resource-poor tropical regions. Outbreaks also occur in developed countries, especially in settings like nursing homes and childcare facilities. It is more prevalent in tropical, overcrowded areas and is associated with poor nutrition, poverty, inadequate hygiene, and homelessness.

The World Health Organization (WHO) classifies scabies as a neglected tropical disease and estimates that over 200 million people are affected at any time, with hundreds of millions more cases occurring annually. WHO also noted that around 5% to 50% of children living in poor hygienic and resource-limited areas worldwide suffer from scabies.

What are the Primary Signs and Symptoms of Scabies?

If a person has not been infected previously, scabies symptoms typically appear 4 to 5 weeks after the initial mite infestation. However, for those who have been infected before, symptoms may appear within 1 to 4 days. The female scabies mite has a lifespan of 1 to 2 months on a person. Once away from the human body, however, mites typically die within 2 to 3 days. The primary scabies signs and symptoms include:

• Skin Itching: Intense itching, particularly severe at night, is the most common sign. This urge to scratch can become unbearable.
• Soreness: Frequent scratching of the affected areas can result in open sores. These may become infected with bacteria, leading to conditions such as impetigo — often caused by Staphylococcus aureus.
• Rashes: The burrowing mites create wavy, thread-like tunnels under the skin. These tunnels result in rashes that may resemble knots, hives, scaly patches, insect bites, or pimples.
• Thick Crust on the Skin: In more severe cases, crusted (or Norwegian) scabies may develop. This form is associated with a weakened immune system and presents as red, scaly, thickened crusts that are crumbly to the touch and can spread rapidly.

Scabies rashes in children can affect the entire body, particularly the soles, scalp, and palms. In infants, symptoms often appear on the soles and palms, causing extreme irritability and disturbed sleep.

Where Do Scabies Usually Appear?

Scabies spreads through direct skin contact. In older children and adults, scabies symptoms commonly appear in the following areas:

• Under the fingernails
• Waistline
• Armpits
• Around the fingerprints
• Inner elbows
• Bends of knees and wrists
• Folds of the genital area and thighs
• Around the nipples

In infants and young children, common areas for scabies symptoms include:

• Face
• Scalp
• Neck
• Soles of the feet
• Palms of the hands

What are the Risk Factors that Cause Scabies?

The microscopic mites responsible for scabies burrow into the skin to feed, lay eggs, and defecate. This triggers the body's allergic reaction, leading to symptoms such as itching and swelling.

Risk factors include:

• Living in crowded conditions with poor hygiene
• Close physical contact with an infected person
• Sharing personal items like towels and clothing
• Weakened immune systems
• Underlying conditions such as HIV or having undergone organ transplantation
• Use of immunosuppressant medications

What are the Common Complications of Untreated Scabies?

Persistent scratching due to intense itching can damage the skin’s surface, leading to soreness and an increased risk of bacterial infections. Common complications of untreated scabies include:

• Painful skin sores
• Secondary infections (e.g., impetigo)
• Insomnia due to itching
• Septicaemia (blood infection)
• Kidney disorders

A serious potential complication is Acute Post-Streptococcal Glomerulonephritis (APSGN), a kidney disease that can arise from streptococcal bacteria entering the skin through scratching. This can lead to kidney inflammation and impaired function.

How to Get Rid of Scabies with Medical Care?

The aim of medical care is to eliminate the mites and relieve the associated symptoms. Here are some medical treatments you can consider for treating this condition. However, make sure to check with your doctor first before continuing with a treatment plan.

Oral Medications

Doctors may prescribe oral ivermectin for patients with crusted scabies or those with compromised immune systems. However, this medication is not recommended for small children, pregnant individuals, or those who are breastfeeding.

Additional treatments may include antihistamines or pramoxine lotion to alleviate itching. Steroid creams are prescribed to reduce swelling and redness, while antibiotics are given if secondary infections are present.

Ointments and Creams

Topical treatments remain the standard care for typical scabies cases. These include:

• 5% permethrin cream
• Lindane lotion
• Crotamiton cream
• 0.5% malathion in aqueous base
• 10–25% benzyl benzoate emulsion
• 5–10% sulphur ointments

Topical scabicides must be applied meticulously to the entire body. For adults, this typically means from the neck down. For infants, young children, the elderly, and anyone with crusted scabies, application must include the entire head, neck, scalp, and forehead. Always follow the specific instructions provided by a doctor or on the product label.

How Do Home Care Options Manage Scabies Symptoms?

Scabies symptoms can improve with proper home care, even as clinical treatment progresses. Home remedies can reduce discomfort and help prevent worsening of the condition.

• Moisturiser Application: Use fragrance-free, gentle lotions to soothe itching and prevent skin dryness.
• Tea Tree Oil: This essential oil has natural antimicrobial and anti-inflammatory properties that may aid in symptom relief.
• Cold Compress: Applying a cool, damp cloth to affected areas can help ease itching and inflammation.

Note: Tea tree oil is not a proven cure for scabies. While it may offer temporary symptomatic relief for some, it should never be used as a substitute for prescription scabicide treatments prescribed by a doctor.

How to Prevent Scabies From Spreading?

Preventing scabies from spreading requires consistent hygiene practices and careful management of personal items. Follow these steps to prevent scabies from spreading:

1. Wash and dry clothes, bedsheets, and towels in hot water and heat-dry them to kill mites.
2. Avoid direct skin contact with infected individuals until treatment is complete.
3. Seal non-washable items in plastic bags for at least 72 hours.
4. Clean and vacuum rooms used by the infested person, particularly if they had crusted scabies.
5. Maintain personal hygiene and keep shared environments clean.

Can Scabies Be Misdiagnosed?

Yes, scabies symptoms can mimic other dermatological conditions such as eczema, psoriasis, or allergic rashes. Misdiagnosis can delay effective treatment. Therefore, accurate diagnosis, which is often performed through visual examination or skin scraping under a microscope, is crucial to identify mite infestation.

Conclusion

Scabies is one of the most common and contagious dermatological conditions seen worldwide, affecting people across all age groups. If left untreated, it can lead to serious complications such as bacterial infections, insomnia, kidney issues, and heart problems. Recognising scabies symptoms, such as intense itching, rashes, skin soreness, and crusted areas, is essential for timely medical intervention.

These symptoms often affect areas like the fingers, neck, palms, and feet. With prompt diagnosis, appropriate treatment, and good hygiene practices, scabies can be managed effectively and prevented from spreading further.