I received an email via our iPhone App from a mother whose 6 year old son had scabies and had been treated two times with permethrin cream, but had just had another re-occurrence. She wondered if there were any other options for treatment.
Scabies is a mite that causes an eczematous skin rash with associated horrible itching. Infestation with the scabies mite is the result of skin to skin contact. The mite burrows beneath the skin and the feces of the mite causes an allergic hypersensitivity reaction with resulting skin inflammation and itching.
It can be fairly miserable when it goes on for awhile. (Once again my own son had it 20 years ago and that was actually one of the first times I had seen the rash of scabies and it took 3 different doctors including an allergist to finally diagnose it! ). It is sometimes easily diagnosed as a child will have a classic rash on their, trunk, arms and legs, and may even has the classic burrow tract of the mite between their toes and fingers.
At other times scabies can be a great masquerader and the diagnosis may be made by scraping the skin and looking at it under the microscope where the actual mite or mite parts may be seen. If in doubt it is always a good idea to do a scraping.
The time from infestation with the mite to actually symptoms may be as long as 6 weeks. During this time the “index” case in a family harbors the mites and are infectious, but they may not yet be symptomatic with the typical rash of scabies.
When you diagnose a child with scabies the most important thing to do is to not only treat the child but treat the entire family unit. Because the mite has such a long infectious incubation period it is important to treat all family members at the same time. The standard treatment is with 5% permethrin cream, which is typically applied at night to all body surfaces from neck to toes. (do not bath before putting on the cream as this will help reduce the systemic absorption of the medicine).
Make sure to get the cream between the web spaces of the fingers and toes. The cream is left on over night (remember entire family) and then washed off in the am. The next day I would wash all of the clothes and sheets in hot water. If there are clothing that will not tolerate this put them in a platic bag for 72 hours (which is the life span of the mite off of the body).
Even after a patient is successfully treated the itching may continue for several more days and may be treated with topical steroid cream (Cortaid over the counter or a prescription steroid cream). What you will notice is that while the intense itching is diminishing, there are no NEW areas of rash.
Most treatment failures seem to be due to not applying the cream with attention to complete coverage, or to not treating the entire family at the same time.
Another medication Lindane (Kwell) has been used to treat scabie, but has been associated with the potential for neurotoxicity and is rarely prescribed, especially for younger children. There is also an antiparasitic medication, Ivermectin that is currently being studied for the treatment of scabies.
That’s your daily dose for today. We’ll chat again tomorrow.