Scabies: The itching that is persistent

Jul 16, 2017 Dr Zulfikar Bux, Features / Columnists

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By Dr Zulfikar Bux

Assistant Professor of Emergency Medicine

From time to time, I would see a patient who itches all over and they cannot get rid of it. Some persons

may think their scabies is an allergy and treat it as such. Scabies is a mite infestation of the skin that can trigger allergic itching.

When a person catches scabies, pregnant female mites dig burrows in the skin and lay eggs along the way. After three to eight days, the eggs hatch and the young mites travel up the burrows to the skin surface. There they grow to adulthood and mate, after which the females become pregnant and continue the skin infestation.

Once a female mite finishes laying her eggs, she spends the rest of her 2-month life span at the deep end of her tunnel. Mite tunnels may be visible in the skin of a person who has scabies, although intense scratching often distorts their appearance.

 HOW IS IT TRANSMITTED?

Scabies mites can be transmitted by direct skin-to-skin contact with an infected person or by using clothing, blankets, sheets, towels or furniture that has touched an infected person’s skin. Scabies easily spreads during the close physical contact of sexual activity. However, scabies also can be passed from person to person in various nonsexual settings in which people live in close quarters, including hospitals, nursing homes, prisons, day-care centres and homes.

Anyone can catch scabies, including doctors, nurses, teachers, toddlers and elderly people in wheelchairs. Having scabies is not a sign that someone is dirty, careless or sexually promiscuous.

Worldwide, approximately 300 million new cases of scabies occur each year in men, women and children of all ages and races. Groups that are especially vulnerable to catching scabies include:

• People who have multiple sex partners
• Anyone who lives in crowded conditions
• Patients and health care workers in hospitals and nursing homes
• Students, teachers and other caregivers in day-care centres
• People who live or work in institutions or prisons

 WHAT ARE THE SYMPTOMS OF SCABIES?

Symptoms of scabies include:

• Intense itching– This itching is often worse at night, and it can involve any part of the skin, not just areas that have rash or nodules.
• A rash– The scabies rash typically affects the following skin surfaces: the hands, especially webbed skin between the fingers; skin folds at the wrists, knees, elbows, underarms, waist or buttocks; the genitalia; the breasts, especially the dark area around the nipple; and the shoulder blades.

In adults and older children, the scabies rash often looks like tiny red bumps that are similar to small insect bites. In infants, it can appear as tiny vesicles (small fluid-filled blisters). Also, the rash can extend to the neck, head, palms and soles of the feet in babies who are younger than two years old.

• Red or brown nodules (larger skin bumps)– In some cases, a person with scabies develops skin nodules rather than a rash. These nodules can be up to five millimetres (one-quarter inch) wide, and they usually occur on skin that is covered by clothing, such as the trunk and upper legs.

HOW IS IT DIAGNOSED?

Most often, the diagnosis is made based on skin findings and known exposure or possible exposure to scabies. The doctor looks for bumps between the fingers and toes and for burrows. The doctor also may scrape an area of rash gently to look for the mites or their eggs.

HOW LONG CAN IT LAST?

With proper treatment, the rash and intense itching of scabies usually begins to subside within one to two days, although some milder itching can persist for a few weeks.

Without treatment, scabies can be a long-term infestation that can spread to other people. During the course of the illness, persistent scratching can lead to chronic crusting of the skin or to painful secondary skin infections caused by bacteria.

 CAN IT BE PREVENTED?

Yes. To help prevent scabies avoid sharing clothing and towels. If someone in your household has been diagnosed with scabies, wash his or her clothing, bedding and towels in hot water, and dry these items in a hot dryer. This should kill all scabies mites and eggs. Clothing that cannot be washed should be sealed and stored for approximately one week, because scabies mites die within one to four days if not in contact with human skin.

WHEN TO SEE YOUR DOCTOR?

Call your doctor if you have symptoms of scabies or if you have been exposed to someone with scabies. Also, contact your doctor if you have been diagnosed with scabies and your symptoms have not improved significantly within one week after completing treatment. Treatment is usually in the form of creams that kill the scabies mite. Your doctor may also prescribe medications to help you with your itching.

If you follow your doctor’s directions for using scabies medication, the prognosis is excellent. In most cases, you stop being contagious within 24 hours, and your major symptoms should improve noticeably within two days.

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