HEALTH TIPS: SCABIES

Dr Tariq Jagnarine
Fam Medicine, Endocrinology/Diabetes

Scabies is one of several skin conditions that can cause itching and rashes. It is a dermatologic condition caused by sarcoptes scabiei, an eight-legged microscopic mite.
• While the scabies mite needs skin to feed on and survive, it can live without a human host for 48 to 72 hours.
• The rash and itching experienced by those with scabies is a result of the body’s allergic reaction to the mites, their eggs, and their waste.
• The average person infested with scabies will have 15 to 20 mites present.
• Those at highest risk of developing crusted scabies include the immunocompromised, the elderly, and those housed in institutional settings.
Each year, scabies affects millions of people of all races, ages, and socioeconomic status. It is highly contagious, being easily spread through close physical contact and by sharing bedding, clothing, and furniture infested with mites. Scabies is estimated to infect over 300 million humans worldwide each year. Scabies most frequently occurs in children and young adults, with outbreaks common in child care facilities, family homes and schools. All persons with scabies and their contacts need to be treated.

CAUSES
Scabies is an infestation of the sarcoptes scabiei mite, also known as the human itch mite. After burrowing under the skin, the female mite lays its eggs in the tunnel it has created. Once hatched, the larvae move to the surface of the skin, and spread across the body or to another host through close physical contact.
Humans are not the only species affected by mites. Dogs and cats can also be infected. However, each species hosts a different species of mite, and while humans may experience a mild, transient skin reaction to contact with non-human animal mites, a full-blown human infection with animal mites is rare.
Scabies is highly contagious, and spreads via direct skin-to-skin contact, or by using a towel, bedding, or furniture infested with the mites. As such, some of the people most likely to become infested with mites include:
• Children attending day care or school
• Parents of young children
• Sexually active young adults and people with multiple sexual partners
• Residents of extended care facilities
• Older adults
• People who are immunocompromised, including those with HIV/AIDS, transplant recipients, and others on immunosuppressant medications

SYMPTOMS
The onset of symptoms of scabies varies, depending on whether or not a person has previously been exposed to mites. The first time a person is exposed to the scabies mite, it can take upwards of 2 to 6 weeks for symptoms to develop. This timeframe is significantly shorter in subsequent infestations, as the body’s immune system is quicker to react, typically within 1 to 4 days.
Signs and symptoms of scabies include:
• Itching: This is often worse at night, and can be severe and intense. Itching is one of the most common symptoms of scabies.
• Rash: When the mite burrows into the skin, it forms burrow tracks, or lines, which are most commonly found in skin folds, and resemble hives, bites, knots, pimples, or patches of scaly skin. Blisters may also be present.
• Sores: These occur in infested areas where a person has scratched at the skin. Open sores can lead to impetigo, commonly caused by secondary infection with Staphylococcus aureus.
• Thick crusts: Crusted scabies, also known as Norwegian scabies, is a form of severe scabies in which hundreds to thousands of mites and mites’ eggs are harboured within skin crusts, causing severe skin symptoms.
Most often, those affected with crusted scabies exhibit widespread grey, thick, crumbling crusts. Mites living in the detached crusts can live for upwards of a week without needing human contact, due to the food provided by the crusts themselves.
The most common sites of infestation in adults and older children include:

• Between the fingers
• Around fingernails
• Armpits
• Waistline
• Inner parts of the wrists
• Inner elbow
• Soles of the feet
• Breasts, particularly the areas around the nipples
• Male genitalia
• Buttocks
• Knees
• Shoulder blades

Infants and young children experience infestation in other areas of the body, including the:

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

At times, children can present with a widespread infestation, covering a majority of the body. Infants who are infested with scabies tend to exhibit symptoms of irritability, and sleeping and eating difficulties.

DIAGNOSIS
Scabies can sometimes be mistaken for dermatitis or eczema, as these skin conditions also cause itching and bumps on the skin. Anyone who is unsure about the cause of a skin condition should consult their physician, as over-the-counter medications cannot eradicate scabies.
Health Care workers can diagnose scabies by examining the skin, or by looking at skin scrapings under a microscope.

TREATMENT
Scabies is highly contagious, so anyone living with a patient diagnosed with the condition, or who has had close contact with the patient, would most likely be recommended to receive treatment for scabies even if they do not have any symptoms. This includes any person with whom the patient has had recent intimate contact.
Scabies is generally treated with topical medications such as 5 percent permethrin cream, crotamiton cream, or lindane lotion. In some cases, a 25 percent benzyl benzoate lotion or 10 percent sulfur ointment may be used. Most topical preparations are applied at night and washed off in the morning.
• Ivermectin, an oral medication, may be recommended for people who are immunocompromised, those with crusted scabies, or those who did not respond to topical therapy.
• Other medications, such as antihistamines, anti-itching lotions, antibiotics, and steroid creams, might be prescribed to offer relief from symptoms.
Treatment with prescribed medications would generally kill mites quickly. The itching and rash may initially become worse.
However, skin healing should be seen by 4 weeks after treatment. Some people require more than one course of treatment to fully rid themselves of mites.

HOME REMEDIES
Home solutions for scabies are often not recommended. Some infestations can resolve without treatment. However, herbal treatments, such as tea tree and neem oils, have not consistently been shown to treat scabies. It is therefore advisable to visit a health facility and be reviewed by a physician.

PREVENTION
To prevent re-infestation and spread, take the following steps:
• Wash or dry-clean all clothes, towels, linens, etc. When washing, use hot soapy water and dry on high heat. Place items that cannot be washed in a sealed plastic bag for one to several weeks to starve the mites.
• Vacuum the entire home on the day treatment is initiated, including carpets, rugs, upholstery, etc., and discard the bag or thoroughly clean the vacuum’s canister.
Anyone can get scabies. It has nothing to do with poor hygiene.