You know what it’s like to have an itch, right? Sometimes for no reason at all your back itches. That’s when a friend or partner can come to your rescue. A mosquito bite can itch. So can poison ivy. As unpleasant as these skin irritations can be, they pale in comparison to the itch of scabies. A reader has a very short poignant question about this hard-to-treat condition.
Q. Is there any cure for scabies? It produces unbearable itching.
A. Scabies is caused by the “itch mite,” Sarcoptes scabiei. Three hundred million people around the world are infected each year. Scabies spreads through skin-to-skin human contact.
These tiny parasites burrow into the top layer of the skin. Their saliva causes intense itching that gets worse at night. It often causes a rash, especially around the belt line or at wrists, elbows and armpits.
To cure scabies, doctors prescribe medications that will kill the mite. There are several options.
Permethrin for the Itch of Scabies?
Permethrin, the same insecticide that is commonly used against lice, is applied as a cream against scabies. A good friend was prescribed this scabicide for his unbearable itch. It helped a bit for a short amount of time. Then the itching resumed with a vengeance. More about that momentarily.
Ivermectin for the Itch of Scabies?
Another reader asks about a controversial drug called ivermectin. Perhaps you remember it as a potential treatment against COVID-19. We won’t deal with that issue in this article. Here is a mother’s dilemma about scabies:
Q. My adult daughter has a prescription for ivermectin to treat suspected scabies. The FDA has not approved this medication for treatment of scabies, so her insurance company thus far has refused to cover the prescription.
Is ivermectin safe for this use? Two healthcare providers (her PCP and dermatologist) have prescribed it.
A. Scabies is an incredibly itchy skin condition. Dermatologists rely on permethrin cream to eliminate the infestation. If that doesn’t work, they may resort to oral ivermectin. The FDA approved this anti-parasitic medication to treat river blindness (onchocerciasis) and intestinal worms (Strongyloides stercoralis). Veterinarians prescribe ivermectin to prevent heartworm in dogs.
Although oral ivermectin is not approved for scabies, there is good evidence that it is effective (JAMA, Sept. 9, 2024). A review in a Spanish dermatology journal noted that:
“Oral ivermectin has been recommended as a systemic alternative to topical scabicides due to its ease of administration, convenience, safety and favourable side effect profile.”
The generic oral medication is reasonably affordable even without insurance.
Our Friend with the Incredible Itch After Permethrin Treatment:
We described a friend who had a resurgence of the itch of scabies after treatment with permethrin. Next, he got an oral dose of ivermectin. Doctors also prescribe this anti-parasitic medication for scabies. The FDA has not approved it for this use.
It took two courses to overcome the infestation. Side effects of ivermectin include dizziness, digestive upset, fatigue, skin rash and itching. Serious reactions include changes in heart rhythm and eye inflammation.
In some places, itch mites are developing resistance to both of these standard treatments (American Journal of Tropical Medicine and Hygiene, Feb. 2016).
Other Drugs vs. the Itch of Scabies:
Doctors sometimes prescribe other drugs that kill the scabies mite such as lindane, malathion or crotamiton, but resistance is becoming a problem for these as well. These medicines are applied to the skin. Crotamiton, for example, is applied to the entire body, left on for 24 hours and re-applied. During the treatment period, the patient should not shower or bathe. Seems a bit daunting, don’t you think?
Tea Tree Oil?
Australian researchers are studying the potential of topical tea tree oil as an additional approach (American Journal of Tropical Hygiene, Feb. 2016). They are currently conducting a randomized controlled trial comparing tea tree oil to permethrin as an active control (BMJ Open, May 31, 2018).
We have searched for the results of this clinical trial without success. That doesn’t bode well for this natural approach. Topical tea tree oil can be irritating to the skin.
Have you ever experienced the itch of scabies. Has anything worked? Please share your experience in the comment section below.
