Scabies is caused by a tiny mite that lives underneath the skin. The female mite is only just visible to the naked eye, about the size of a pin head.
The female burrows and excavates a small tunnel in the skin, in which she lays her eggs. The process of burrowing irritates the skin and promotes scratching, which in turn helps the mite spread further, as eggs and adult mites are picked up under the fingernails and transferred to other parts of the body. The scabies mite tends to favour skin folds.
Scabies are most active when the body is warm such as when in bed, or just out of a hot bath, so itching tends to be at its worst at these times. When the mites have been present for a long time, the skin may develop a sensitivity to them and cause a wide spread rash.
Signs and Symptoms
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- Tiny wavy lines under the skin surface
- Small, clear fluid-filled spots or bumps
Commonly affected sites are the wrists or between the fingers and toes, wrists, elbows, knees and buttocks, the penis and scrotum. On the penis, because the skin is loose and soft, the burrows become small raised scabs, especially when scratched.
- Skin to skin by close physical contact
- Incubation period approximately one month
- Generally, scabies are not spread through shared objects such as clothes or bedding
Treatment for scabies is by applying a permethrin 5% solution to the skin. This can be bought over the counter at pharmacies – follow the directions on the bottle. Wash clothing, towels and bedding in hot water whilst being treated. Also all sexual partners and other family members require treatment, even if they don’t have symptoms, to prevent re-infection.