Ditch the Itch for Good: Understanding and Treating Scabies

A 2020 study rightly labelled scabies as a ‘neglected global disease’. In India, the incidence ranges from 13% to 59%. Being a highly contagious disease, scabies is often misunderstood and stigmatised. However, the condition is treatable and can be contained when detected early. Physicians and everybody else must prioritise the causes, signs, symptoms, and prevention methods of scabies. 

Scabies is a contagious skin condition caused by a parasitic mite that burrows inside the skin. It spreads through skin-to-skin contact between infected people and is typically characterised by incessant itching. Although less common, scabies can even spread through sharing clothing, towels, or bedding used by an infected person. The mites can survive on these items for a short period, typically 48–72 hours. In 2009, the World Health Organization (WHO) declared scabies as a neglected skin disease — a significant health concern in many developing countries. Careful and prompt diagnosis is needed to prevent outbreaks.

Scabies is caused by a parasite called Sarcoptes scabiei var. Hominis, which lives in the epidermis or outer layer of the skin.

• Typically seen in tropical countries with high populations and poor living conditions, scabies can affect all age groups. 
• Misdiagnosis due to poor healthcare facilities and delayed medical care is critical in scabies outbreaks. 
• History shows that scabies outbreaks are also possible in developed nations during war situations or amid natural calamities.

Intimate contact, like sexual intercourse with an infected person, can also cause scabies.

• Classic: This demands skin-to-skin direct contact for about ten minutes. It can also be transmitted through clothing or bed sheets (fomite transmission). It typically affects palms, soles and under fingernails.
• Nodular: This is a variant of the classic form, with a predisposition towards the axilla and groin. 
• Contagious: The contagious crusted variant, also known as Norwegian scabies, is more common in immunocompromised patients due to immunosuppressive therapy, diabetes, HIV or old age. The number of mites transmitted simultaneously ranges in millions, so a short contact is sufficient.
• Scabies-in-clean: The term "scabies in clean" refers to scabies infestations in people who maintain good personal hygiene and regularly bathe or wash. Even though these individuals may have clean skin and good hygiene practices, they can still contract scabies through close contact with an infected person or contaminated items.

The rash in "scabies in clean" may be less severe or widespread, making diagnosis more challenging, but intense itching, especially at night, remains a hallmark symptom.

Typically, scabies bites or infestations on the skin can have multiple presentations, including:

• Raised bumps with a clear top filled with fluid that is scattered
• Rashes can appear in a row.
• Lines, discoloured bumps and scaly patches on the skin.

Once transferred, the female mites lay eggs in burrow tunnels on the skin. However, they die 30-60 days later, and eggs hatch 2-3 weeks later. Early treatment may not penetrate the stored eggs.

The rashes, or ‘papules’, appear 2-5 weeks after infestation. These are tunnel- or comma-shaped and red, slightly raised, blister-like, and range in length from a few millimetres to one centimetre. The rashes will accompany severe itch, crusting and a mild change of colour.  The most noticeable scabies symptoms are intense itching, which worsens at night or after a hot shower and burrowing tracks. 

They are typically found under thin skin in regions such as:

• Finger/toe folds
• Inner elbows
• Chest
• Buttocks
• Areolae of the nipples
• Navel region
• Penis shaft

This characteristic distribution forms an imaginary circle on the upper and mid-body, called the Circle of Hebra. It highlights the areas where scabies mites are most likely to burrow and cause the typical itching and rash.  Recognising the Circle of Hebra helps diagnose scabies.

Without timely treatment, the scabies infection might spread to other community members, resulting in an outbreak within the population.

The possible consequences of scabies infection, rather than the complications, include persistent itching that bruises the skin, sleeplessness, subsequent bacterial infection on the bruised skin, and exponential disease outbreaks in the community.

There are many treatment options for scabies. They are to be used by the entire infected community together under the doctor's strict supervision. However, as an epidemic, it is critical to contain the infestation of scabies. This makes scabies prevention tips important for both people and doctors. Here’s what Dr. Snehankita Chawdhry, MBBS, MD, DVL, Dermatology, says:

“Apart from medications prescribed by a healthcare provider, other important points to remember while taking treatment for scabies include:

1. Most topical anti-scabetic creams are applied neck down in adults, but in children, they should also be applied on the face.
2. Ensure simultaneous treatment of all household members and close contacts, even if they show no symptoms.
3. Wash all clothes and bedding in hot or boiling water, and dry them in a dryer or inside out in the sun.
4. Ironing the inside of clothes can help kill mites if any remain.
5. If certain items cannot be washed or dry-cleaned, store them in an air-tight plastic bag for up to seven days.
6. Itching may persist for up to a month but will gradually reduce with treatment.”

This advice ensures effective management and minimises the risk of re-infestation. Remember that preventive measures can prevent re-infection for those who have already been exposed to scabies and halt its spread to neighbours who may come into contact with the person in the future.

Understanding the symptoms, causes, and effective prevention methods for scabies is crucial in managing and mitigating the spread of this uncomfortable and contagious skin condition. Prevention remains the most effective strategy in controlling scabies outbreaks. They can help communities protect themselves from scabies and ensure a healthier, happier environment.

Scabies is caused by direct skin-to-skin contact with an infected person. Transferring the scabies mites may take a few minutes to up to ten minutes.

No. Scabies mites are not visible to the naked eye.

Scientific research shows that scabies mites can live on the skin and remain viable for up to two months. 

While both feed on the human skin and are parasites, unlike scabies, bedbugs don’t burrow homes in the skin. They remain outside after biting the skin. 

No. As it is a parasitic infection, prescription drugs and cleanliness protocols are a must.

It is hard to identify scabies at home as they may resemble other skin rashes; you must see a doctor immediately.