Fixing a stubborn case of scabies
What is a “stubborn case” of scabies?
A stubborn case is one that is not cured by using any of the scabies treatments two weeks in a row (you can see the treatment schedules here).
If you are not cured there are three possibilities:
Why clinical studies can be misleading
If you ever read clinical studies where they test how effective various scabies treatments are you will see marvelous cure rates for some treatments. Often there are claims of 80% or 90% cure rates. The researchers are being honest but they have a little unhidden secret…before they start a trial they eliminate “complicated” cases.
What is a complicated case?
One problem with studies “proving” stuff “works” is most studies are careful to weed out complicated cases.
You might be surprised what a “complicated” case is. It is anything which might make it hard to know what is causing the results.
For instance, researchers might eliminate
- People who have tried any other treatment in the previous month.
- Anyone who has taken antibiotics or has a bacterial infection.
- Pregnant women.
- Children or babies
- Folks who have an auto-immune disease.
- People who don’t have the right symptoms in the right places
- Some other chronic condition (breathing problems, overweight, diabetic, etc)
- Etc, etc.
“…60 percent of American adults had at least one chronic condition, and of those patients, 42 percent had multiple chronic conditions.” (References here and here) That’s a lot of people who might be excluded!
So that tends to not take into account complicated or stubborn cases. No wonder these treatments get glowing results with 80% or 90& or higher cure rates!
So it is not that anyone is faking anything. The results are useful for uncomplicated cases.
But doctors don’t like thinking about such things.
They need simple instructions because they need to feel sure they are doing the right thing.
This is why doctors love case studies (describing a single “standard” person’s treatment and outcome) but run away screaming from clinical studies because they are simply too fuzzy…clinical studies have all these percentages and variations and are just too messy for the average GP (general practitioner).
And I get it. It’s similar to a car mechanics who doesn’t really want to know why a part failed, they simply replace that part and see if that does the trick.
What does this mean to you?
For people who have uncomplicated cases, it means they are easily cured with a couple applications of any of the scabies treatments a week apart. It’s hard to tell exactly, but I’m guessing about 60% of people are in that group.
But it means a sizable group of people are not cured that easily. They have stubborn cases.
I hear from a lot of people who are having a hard time getting cured and feel let down by all the glowing promises in the clinical trials.
And doctors can sometimes think you “should” be cured by a couple applications and if you aren’t, well then, you can’t have scabies. Maybe you’re just imagining the whole thing (you’re nuts). That’s pretty frustrating for sufferers. But it lets doctors off the hook so they don’t feel like failures.
The program for stubborn cases is to do weekly treatments for five or more weeks. And also to do an oral treatment at the same time (such as ivermectin or moxidectin).
It might also mean trying one topical treatment, such as 5% permethrin cream, and if that doesn’t work, then try some other treatment. I list many different treatments to choose from here.
Many people ask “What is the best treatment?”. I have to answer that all the treatments work, but they don’t all work for everyone. I realize that means you are gambling when you choose, but that’s just reality.
Over the years treatments preferences have shifted, mostly because of smell or skin irritation.
Sulfur is the oldest treatment, but it smells and can give you dry skin and a mild sort of sunburn and you have to apply it 3 days in a row each week. So sulfur got replaced by benzyl benzoate which you only apply once or twice a week and it doesn’t smell. But benzyl benzoate can sting or have a temporary burning sensation so it got replaced by permethrin which doesn’t sting or smell but for some folks it can irritate their skin. Last year (2022) along comes spinosad which doesn’t smell, and is non-irritating and you only apply it once a week.
And then ivermectin became OK to prescribe for scabies so sometimes that is chosen as it is so easy…just pop some pills.
But no one treatment is guaranteed to cure you.
American doctors are stuck in the past so they tend to prescribe permethrin cream.
Japanese doctors are really conservative and tend to prescribe sulfur lotion.
In France you might get ivermectin pills first.
In Australia benzyl benzoate has been preferred.
I hope you have a picture about why there is so much variation in what you get depends on where you live.
So what is the basic treatment plan for stubborn cases?
I think if I caught scabies again I would try topical spinosad once a week and oral ivermectin once or twice a week for 5 weeks. I would not want to just do two weeks of treatments and then sit around waiting to see if it came back. I would just do the treatment for stubborn cases right off the bat.
And I might do some other topical treatment on the in-between days.
