Scabies is a transmissible ectoparasite skin infection characterized
by superficial burrows, intense pruritus (itching) and secondary
infection. The word 'scabies' is Latin for 'itch'.
Caused by the mite Sarcoptes scabiei, variety hominis, it produces
intense, itchy skin rashes when the impregnated female tunnels
into the stratum corneum of the skin and deposits eggs in the
burrow. The larvae, which hatch in 3-10 days, move about on the
skin, molt into a "nymphal" stage, and then mature into adult
mites. The adult mites live 3-4 weeks in the host's skin. The
motion of the mite in and on the skin produces an intense itch
which may resemble an allergic reaction in appearance. The presence
of the eggs produces a massive allergic response which, in turn,
produces more itching. Scabies is transmitted readily, often throughout
an entire household, by prolonged skin-to-skin contact with an
infected person (e.g. bed partners), and thus is sometimes classed
as a sexually transmitted disease. Spread by clothing, bedding
or towels is a less significant risk, though possible.
It takes approximately 4-6 weeks to develop symptoms after initial
infestation. Therefore, a person was contagious at least a month
before they were diagnosed. This means that person could have passed
scabies to anyone at that time with whom they had close contact.
Someone who sleeps in the same room with a person with scabies has
a high possibility of having scabies as well although they show
no symptoms.
The symptoms are caused by an allergic reaction that the body
develops over time to the mites and their by-products under the
skin, thus the 4-6 week "incubation" period. There are
usually relatively few mites on a normal, healthy person--about
11 females in burrows. Scabies are microscopic although sometimes
they are visible as a pinpoint of white, but most people can't
see them. The females burrow into the skin and lay eggs there.
Males roam on top of the skin however can burrow and do, but both
males and females surface at times especially at night. They can
be washed off or scratched off (however scratching should be done
with a washcloth to avoid cutting the skin as this can lead to
infection), which, although not a cure, helps to keep the total
population low. Also, humans create antibodies to the scabies
mites which do kill some of them.
People with compromised immune systems do not develop antibodies
to the mites and may develop crusted Norwegian scabies, where
many form scabs or have very red skin especially in the elderly
and the mentally handicapped where white or gray crusted areas
develop with little itching and little or no red bumps and mite
population numbers soar to hundreds, thousands, or in AIDS patients
millions. These cases require additional treatment options to
ensure a complete kill. Ivermectin is the treatment of choice
in these patients combined with any other topical treatment.
The systemic approach involves a drug called Ivermectin, generic
name Stromectol. A dosage is prescribed according to weight at
least 12 mg for an adult, taken all at once and repeated in seven
days if necessary. This is the easiest and quickest method although
most doctors are as yet unfamiliar with this treatment.
After treatment has been applied or taken, (or directly before
treatment if you are careful and wear gloves) cleaning of environment
should occur. Wash all recently worn clothing in hot water and
dry in a hot dryer. There is no need to wash clean clothes that
haven't been touched in the past week. Place clean clothes on
a clean sheet out of the dryer. Things that cannot be washed can
be dry cleaned. Place other stuffed animals and pillows in a plastic
bag for two weeks or freeze these items and shoes in the freezer
overnight in a plastic bag with twist tie. This will kill any
mites. Towels and bedding should be removed and washed daily for
at least three days after each treatment, including mattress pad
and pillow covers. Pillows can be tossed in hot dryer for 30 minutes
and mattresses can be vacuumed. Vacuum all carpets, rugs and upholstered
furniture daily. Don't forget about things like coats, gloves,
hats, slippers, robes, kitchen towels, wetsuits, etc. Either isolate
long enough for the mites to die in a plastic bag (at least 2
weeks) or clean or freeze overnight. Mop all floor surfaces and
clean bathroom surfaces (this only needs to be done after the
first treatment). Thoroughly clean brushes and combs too (this
is extra precaution and may not be necessary). This routine needs
to be repeated at the time of the second follow-up treatment to
ensure a thorough kill.
If there are pets in the house, they should be either treated
with a pemethrin shampoo at the same time as the humans or isolated
and treated with Revolution. There are other herbal treatments
if desired. Ivermectin products are also available for pets.
Expect increased itching and red bumps for the first week after
taking any medication for scabies. The dead mites
remain in the skin for 30 days. They are removed
with the body's natural shedding process. During
those 30 days expect new bumps and itching.
