Scabies (Kudis Buta / 疥疮): Symptoms, Treatment and Why It Keeps Coming Back
By Dr Lim Tzyy Huei | Consultant Dermatologist, Pantai Hospital Batu Pahat, Johor, Malaysia
Do you experience intense itching, especially at night? Have you noticed small itchy bumps on your fingers, wrists, waist or other parts of your body?
Perhaps other family members have also started scratching.
These could be signs of scabies, a contagious skin condition commonly known as kudis buta in Malay and 疥疮 in Chinese.
Scabies can cause persistent itching, disturbed sleep and considerable discomfort. It is sometimes mistaken for eczema, an allergic reaction or insect bites.
Although scabies is treatable, successful management involves more than applying an anti-itch cream.
Correct medication application, treating close contacts at the same time and following simple household precautions are important to prevent the infestation from spreading or returning.
What Is Scabies?
Scabies is a skin infestation caused by a microscopic mite called Sarcoptes scabiei var. hominis.
These tiny mites burrow into the outer layer of the skin, where they live and lay eggs.
The body's immune reaction to the mites and their waste products causes an itchy, inflammatory skin rash.
Scabies is not caused by poor hygiene.
Anyone can develop scabies, regardless of age, cleanliness or living conditions.
What Are the Common Symptoms of Scabies?
The most characteristic symptom is intense itching that becomes worse at night.
Other common features include:
Small red or skin-coloured itchy bumps
Persistent scratching and disturbed sleep
Tiny, curved or wavy lines on the skin, known as burrows
Scratch marks, crusting or small wounds
Eczema-like patches caused by repeated scratching
Which Parts of the Body Are Commonly Affected?
Scabies frequently affects:
Between the fingers
Wrists and hands
Armpits
Waist and abdomen
Buttocks and groin
Genital area
Skin around the nipples
In babies and young children, scabies may also affect the scalp, face, palms and soles.
Not everyone develops visible burrows. Some patients only have scattered itchy bumps or eczema-like patches, making the condition more difficult to recognise.
How Does Scabies Spread ?
Scabies spreads mainly through prolonged, direct skin-to-skin contact with someone who has the infestation.
Common situations include:
Living in the same household
Sharing a bed
Close physical or intimate contact
Providing personal care to an affected person
Living in crowded environments, such as dormitories or care facilities
Transmission through shared clothing, towels or bedding is less common in ordinary scabies, but it can occur.
Scabies does not usually spread through brief contact, such as a quick handshake.
Can Someone Spread Scabies Without Having Symptoms?
Yes.
When someone develops scabies for the first time, itching may take approximately 4–8 weeks to appear.
During this period, the person may already be able to transmit the mites to others.
For someone who has previously had scabies, symptoms may develop much faster following reinfestation.
This is one reason why treating only the family member who is currently itchy may not be enough.
How Is Scabies Diagnosed ?
A dermatologist can often diagnose scabies by assessing :
The pattern and severity of itching
The distribution of the rash
The presence of characteristic burrows or skin changes
Whether other household members or close contacts have similar symptoms
In selected cases, dermoscopy or skin scraping may help identify mites, eggs or mite waste products.
However, a negative skin scraping does not completely rule out scabies.
Because scabies can resemble eczema, insect bites and other itchy skin conditions, an accurate diagnosis is important, particularly when symptoms persist despite treatment.
What Are the Treatment Options for Scabies?
The main goals of treatment are to eliminate the mites, relieve symptoms and prevent transmission or reinfestation.
1. Permethrin 5% Cream
Permethrin 5% cream is commonly recommended as a first-line treatment for ordinary scabies.
It works by killing the scabies mites.
Correct application is essential because applying the cream only to visible rashes may leave mites in other areas of the skin.
How to Apply Permethrin Correctly
Apply the cream to clean, dry and cool skin, usually at night.
For most adults, apply it thoroughly over the entire body from the neck down, including areas without visible rashes.
Pay particular attention to the spaces between fingers and toes, under the fingernails, wrists, genital area, buttocks and soles.
Leave the cream on for approximately 8–12 hours, or according to your doctor's instructions, before washing it off.
If you wash your hands during the treatment period, reapply the cream to your hands.
Repeat the application approximately 7 days later, as instructed.
For infants, young children and certain older or immunocompromised patients, treatment may also need to include the scalp, neck and face, while avoiding the eyes and mouth.
The exact treatment area and application instructions should follow medical advice.
Important: Do not apply permethrin only to the itchy areas. Mites may be present even where the skin looks normal.
2. Oral Ivermectin
Oral ivermectin is another treatment option that may be considered in selected patients, particularly when topical treatment is difficult, impractical or has not been successful.
It may also form part of the treatment for more severe forms of scabies.
For ordinary scabies, treatment generally involves two weight-based doses, approximately 7–14 days apart.
Ivermectin is not suitable for everyone. Its use during pregnancy and in children weighing less than 15 kg requires particular caution because safety information is limited.
The choice between topical and oral treatment should be based on the patient's age, weight, medical condition, treatment history and other relevant factors.
3. Treatment for Persistent Itching
Even after the mites have been eliminated, the skin may remain itchy because the immune system continues reacting to the infestation.
Depending on the skin condition, your dermatologist may recommend:
Moisturisers to reduce dryness and improve skin comfort
Topical corticosteroids to relieve residual inflammation or eczema
Antihistamines for symptomatic relief in selected patients
Additional treatment if a secondary bacterial infection develops
These treatments help relieve itching and inflammation, but they do not replace medication that kills the scabies mites.
Why Must Family Members and Close Contacts Be Treated Together?
This is one of the most important steps in preventing scabies from returning.
Household members, sexual partners and other close contacts generally need treatment at the same time, even if they have no itching or visible rash.
For example, one family member may complete treatment successfully but become reinfested through contact with another family member who was not treated.
Because symptoms can take several weeks to appear, waiting until everyone starts itching may allow the infestation to continue spreading.
Simultaneous treatment helps break this cycle.
How Should You Clean Your Home During Scabies Treatment?
Scabies mites generally survive for only about 2–3 days away from human skin.
For ordinary scabies, extensive household disinfection is usually unnecessary. However, several practical precautions can help prevent reinfestation.
What Should You Do on Treatment Day?
Wash recently used bedsheets, pillowcases, towels and clothing, particularly items used during the previous three days.
Use hot water and a hot dryer when the fabric allows.
Place items that cannot be washed into a sealed plastic bag for several days to one week.
Change into clean clothing and use clean bedding after treatment.
Avoid sharing towels, clothing and bedding during the treatment period.
Avoid close skin-to-skin contact until the initial treatment has been completed, and follow any additional advice about resuming close contact.
There is usually no need to spray insecticides throughout the house, discard mattresses or throw away furniture.
For crusted scabies, which is a more contagious form of the condition, more intensive household and infection-control measures may be required.
Why Am I Still Itchy After Scabies Treatment?
One of the most common questions patients ask is:
“Doctor, I have already applied the scabies cream. Why am I still itching?”
Persistent itching does not always mean that scabies treatment has failed.
After the mites are killed, the immune system may continue reacting to mite remnants and their waste products.
This is known as post-scabetic itch.
Itching may continue for several weeks, even after successful treatment.
Some patients also develop post-scabetic eczema or persistent itchy nodules, which may require additional anti-inflammatory treatment.
How Can You Tell Whether Scabies Is Improving?
Signs suggesting recovery | Signs that may require reassessment |
Itching gradually becomes less intense | Itching continues to worsen |
No new burrows appear | New burrows or characteristic bumps appear |
Existing rashes slowly improve | New rashes develop in typical scabies locations |
Household members are improving | Other close contacts continue developing symptoms |
These signs are helpful but are not always definitive.
If itching persists beyond 2–4 weeks, becomes worse or is accompanied by new characteristic lesions, reassessment may be necessary.
Avoid repeatedly applying scabies medication without medical advice, as excessive treatment can irritate the skin and worsen itching.
Why Does Scabies Keep Coming Back?
Repeated episodes of scabies can be frustrating, especially when several household members are affected.
However, recurrence is often caused by reinfestation or incomplete treatment, rather than the medication no longer working.
Common reasons include:
1. Family Members Were Not Treated Together
An untreated family member or close contact may continue carrying mites and transmit them back to someone who has completed treatment.
2. The Cream Was Not Applied Properly
Applying permethrin only to itchy areas or missing places such as finger spaces, under the nails, genital area or soles may allow mites to survive.
3. The Second Treatment Was Missed
A repeat application is commonly recommended to improve the likelihood of successful treatment. Skipping the scheduled second treatment may reduce treatment effectiveness.
4. Re-exposure to Someone With Scabies
Continued close contact with an untreated person can lead to reinfestation, even when the original treatment was performed correctly.
5. Post-Scabetic Itching Was Mistaken for Active Scabies
Itching may remain for several weeks after successful treatment.
This does not necessarily mean that mites are still present.
6. The Original Diagnosis Was Incorrect
Other skin conditions, including eczema, contact dermatitis and insect-bite reactions, can resemble scabies. If the rash persists despite correctly completed treatment, a dermatologist can reassess the diagnosis and decide whether further medication is necessary.
Can Scabies Cause Complications?
Repeated scratching can damage the skin barrier, creating small wounds and increasing the risk of secondary bacterial infection.
Possible signs include:
Increasing redness or swelling
Painful or tender skin
Pus formation
Yellowish crusting
A less common but more serious form, known as crusted scabies, may cause thick, crusted or scaly skin containing very large numbers of mites.
Crusted scabies is highly contagious and requires prompt medical assessment, often with a combination of treatments.
When Should You See a Dermatologist?
A dermatological assessment may be helpful if:
You experience persistent itching, particularly at night.
Several family members develop similar itchy rashes.
Symptoms do not improve after completing treatment.
New itchy bumps or burrows continue appearing.
You develop painful, crusted or infected skin.
You are unsure whether the rash is scabies, eczema or another skin condition.
Early diagnosis and appropriate treatment can help relieve symptoms, reduce unnecessary medication use and prevent transmission to others.
Final Thoughts: Treating Scabies and Preventing Recurrence
Scabies is a common and treatable skin condition, but the itching can be very uncomfortable, especially when it affects sleep or spreads among household members.
Successful treatment involves more than treating the visible rash.
Applying medication correctly, treating close contacts at the same time and following appropriate household precautions are essential to prevent reinfestation.
It is also important to remember that itching may continue for several weeks after successful treatment. This does not automatically mean scabies is still active.
With correct treatment and appropriate follow-up, most patients recover successfully.
Dr Lim Tzyy Huei（林子辉医生） is a Consultant Dermatologist practising at Pantai Hospital Batu Pahat, Johor, Malaysia.
Dermatology consultations are available for scabies, persistent itching, eczema, skin infections and other inflammatory skin conditions.
Disclaimer: This article is intended for general patient education and does not replace individual medical consultation, diagnosis or treatment advice. Treatment suitability and application instructions may vary according to age, pregnancy status, medical conditions and clinical findings.
