Yvonne HansonSenior Infection Prevention Nurse

Aims and Objectives:

By the end of this session – you will definitely be itching! And know:• what the scabies mite looks like• a little about their history• what signs and symptoms to look for• and understand the difference between ‘normal’

scabies and ‘crusted’ scabies• how to apply treatment• that you do not want to catch them – ever!

•

Sarcoptes scabiei (scabies)

It is a worldwide disease, more common where overcrowded conditions prevail

However, It can affect any individual irrespective of social class, caste, age , gender or race

Pretty? (magnified 50 times in order to see it)!

MouthSuckers to keep itInside the burrow

joints are used for cutting

The Scabies Mite (female)

Creamy white body

Brown legs

Eggs

Mite

Faeces

History

• “Scabies” is derived from the Latin word for “scratch” (scabere) and the Greek sarx (flesh) and korptein (to smite or cut)

• It is suspected that some biblical “leprosy” (Hansen’s disease) was actually scabies

• Aristotle (384-323 BC) mentioned "lice in the flesh" that produced vesicles

• Archeological evidence and Egyptian hieroglyphics, suggests Scabies has been irritating mankind for at least 2,500 years!

And Kirklees and Wakefield PCTs!

• World wide there are an estimated 300 million cases a year

• immunocomprimised people more likely to develop Norwegian (crusted) scabies.

• 7% of people will develop nodular scabies (nodules can last for several months)

Life Cycle of the Scabies Mite

Cycle normally takes just 12 days

Population of mites

• Numbers of adult mites (burrows) build up slowly

• Symptoms only start after several weeks

• The number of active females increases until– Immune response inhibits

increase– Scratching eliminates many

burrows

Adult female• Adult female mites form

burrows in the stratum corneum (dry horny layer of skin)

• They cut into the cells using sharp “elbow” joints on the front pair of legs and secrete a skin dissolving enzyme

• Usually only have 10 – 15 live mites on the body

• Obligate parasite (lives its entire life on the host)

• Newly matured females form a short burrow and wait for a male to find them

• Males and females mate in the burrow• Males then wander off – in search of other

females• They lay eggs, defecate (scybala), and die in

the burrow• The female enlarges the burrow and stays

there for the rest of her life – burrows about 2-5mm per day (nodular scabies if she goes too deep)?

• Larva makes its way to skin surface• Female may live for 60 days• Can lay 150 – 180 eggs• Can ‘travel’ 10 – 15 cm under the skin

Site where she has burrowed

Mite, just under the skin

How is scabies transmitted/contracted?

• It cannot fly, but can crawl as fast as 2.5 cm per minute• Juvenile mites run around on the skin surface

– Able to transfer– Short-lived – 3 days per stage– Can mature on new host – females and males

• Male mites run around on the skin surface– Able to transfer– Not able to reproduce

• Female mites in burrows– Long lived – cannot leave burrow– Not able to transfer

Factors affecting transmission

• Scabies is transmitted during prolonged skin to skin contact (hand holding is the most common way)– To allow the mite to cross over– To allow enough mites to cross over

• It can be sexually transmitted• ‘Normal’ scabies is not usually transferred via linen, but

‘crusted’ scabies can be

• Can be up to 6 – 8 weeks before first symptoms develop:

– Mild fever– Irritability of skin, soon followed by severe itching (worse at

night)– Non-specific rash on

• Midriff• Thighs• Wrists and forearms

• Unfortunately, these signs are often overlooked, long term can result in eczema and dry areas

• Infants often develop pustules on hands and feet

Signs and Symptoms

Photographs

Hand and Wrist

Webbing (between fingers)

Wrist

Front of hand – does it look like a skin problem you have seen before?

Scabies or Eczema?

Scabies is a great masquerader that mimics other skin problems, e.g. impetigo, vasculitis, insect bites, psoriasis, all of which complicate diagnosis

Diagnosis (Why is it known as the ‘seven year’ itch)?

Clinical diagnosis

• Skin scrapings

• Clinical diagnosis (what do we see)?

• Ink test

Treatment:

The most difficult job is treating asymptomatic contacts – why?

Rules for treating • Although mites may only burrow in certain places juveniles may be

found over the whole body• Wearing gloves and a disposable apron, apply cream or lotion to

cool dry skin (not after a hot bath) to all skin surfaces from head to toe (study): including under nail ends – is especially important for infants and elderly awkward places such as the back, soles of the feet, between fingers and

toes, and the genitals. Pay special attention to the areas where mite burrows most commonly

occur, the front of the wrists and elbows, beneath the breasts, the armpits, and around the nipples in women.

• Repeat treatment after 7 days• If you wash your hands before end of treatment - reapply

Treatment options

• Malathion 0.5% liquid– Used from 1980s

• Needs 2 applications• Requires thorough

application• Not irritant

• Unclear how effective• Possible resistance

Treatment options

• Permethrin 5% cream– Used since early 1990s

• Needs 2 applications• Can cause tingling and/or

numbness (paraesthesia)• Often need >1 tube

• Has the best clinical evidence - >90% effective

Scabies in Care Homes

• The normal chain of contacts in care is complex– Residents

• Resident relatives and friends

– Care staff• Care staff families and friends

– Non-care staff and visiting workers• Need to set up a hierarchy of risk

Treatment of Scabies Outbreak in a Nursing Home

Resident Staff Member

Yes Affected No

D1 Permethrin Permethrin

D7 Permethrin No Treatment, monitor over the next 7 days

Monitor & retreatif necessary usinga topical + Ivermectin

D14

D21 A 2nd Ivermectin dose + topical may be needed in cases of severe crusted scabies

AffectedYes No

Staff Family Unaffected member family

member

Staff

If signs & symptoms are evident begin treatment

Unaffected family members

Permethrin Permethrin Permethrin Permethrin No treatment

Permethrin Permethrin No Treatment No Treatment but monitor

Monitor & retreat if necessary

N.B. The itch of scabies continues for 2 weeks or more following treatment. Relieve the itch with Eurax or calamine.

In severe cases of crusting using an emollient to help remove crusts will enable treatment to work more effectively.

After treatment

• Itch can persist for up to 2 weeks – may require separate therapy

• Nodular scabies – nodules can remain for months (not infectious)

– Antihistamines, creams

Environmental Precautions

• Patients clothing should be placed into soluble bags• Hoover bags should be discarded after each use into

a plastic bag and tied immediately• Clothes, towels, and bed linen should be machine

washed at 50°C or above after the first application of treatment. This kills the scabies mites.

• Keep any items of clothing that cannot be washed, in plastic bags for at least 72 hours to contain the mites until they die

• Pressing clothes with a warm iron, dry cleaning, or putting items in a dryer on the hot cycle for 10–30 minutes is also effective

Crusted Scabies

Norwegian (Crusted Scabies) is:

• Highly contagious due to the large number of parasites embedded in the crusts possibly close to 1 million mites!

• Crusted scabies is more easily transmitted through contact with towels, bedding and upholstery

Points to Note:

• Notify the Health Protection Unit (HPU) of outbreak (two or more residents affected)

• Do liaise with the local infection control team or HPU for support and advice• temporarily close to admissions / respite patients until completion of the first

treatment (post an outbreak notice on the door)• Follow the outbreak care pathway (downloadable from the IPC website)• All GPs should be informed of the problem • Staff who have had one treatment can return to work• If you have had scabies once, you can catch it again (symptoms will show sooner)• Persistent symptoms for more than 3 weeks may indicate that the treatment has

not been successful (risk assess as further treatment may be required• Secondary bacterial infections can develop as a result of scratching (may require

antibiotics)• It is really important to maintain vigilance – remember symptoms may not show

until up to 6 weeks after contracting the infection• Everyone who is treated should be treated on the same day• Scabies cannot be caught from pets or other animals

Are you itching to ask questions?