I often write about the potential direct and indirect harm that can come from the various forms of so-called complementary/alternative/integrative medicine. I have even discussed several cases where children have suffered serious injury or even death, but I can count on one hand how many times I have encountered such a patient myself. Sadly, my streak was recently broken by a case of severe chemical burns caused by the well-meaning application of garlic paste to the skin of a child with a presumed fungal infection.

This won’t be the first time that a discussion of garlic has graced the pages of Science-Based Medicine. It’s a popular remedy that is frequently recommended by naturopaths and well-meaning friends and families for a vast array of complaints, after all. The evidence in support of any true medical benefit, as discussed by our own Scott Gavura back in June, is lacking. I will say, however, that the evidence in favor of culinary efficacy is definitely trending positive, though this is an entirely subjective assessment.

Scott’s post focused on systemic garlic taken in the form of supplements for medical concerns such as heart disease, diabetes, infections, and even allergies. And while there is some potential benefit when it comes to the first two on that list, the evidence so far is flimsy and don’t justify recommendations for that purpose. Topical applications are another common way that garlic is used for medicinal purposes, and one in which the risk to benefit assessment is vastly more problematic.

Topical garlic is typically recommended for a variety of skin ailments because of it’s antimicrobial and anti-inflammatory properties, which are real…in a petri dish. They just haven’t been proven to equate to clinical benefit in humans. The internet is full of articles recommending topical garlic preparations based on those properties, however. This one from Perfect Image is fairly representative and claims that topical garlic can help with alopecia, warts, fungal infections, psoriasis, keloids, corns, and leishmaniasis.

The above article at least does mention the possibility of allergic and irritant dermatitis, though it leaves out the possibility of 2nd degree burns in children. Thankfully the specific recommendations for how to apply the garlic they discuss, with short exposure times and absent occlusive wrappings, are unlikely to cause any severe injuries even if used on a child. Not all online resources are as careful about recommending topical garlic. This one from Medical News Today recommends a lengthy exposure and gauze wraps, and also doesn’t mention the possibility of severe injury.

Walnut Creek Naturopathic, among others, recommends intravaginal garlic for yeast infections:

A garlic clove can also be inserted into the vagina to kill the yeast off locally. Peel the garlic clove carefully, so as not to nick it, and insert it vaginally at bedtime for 6-8 hours. You can also thread the garlic like a necklace for easy removal. Otherwise, the garlic may occasionally be harder to remove. Relax. It is in there somewhere! In all seriousness, it can sometimes tuck itself behind your cervix. Bearing down as if you are having a bowel movement while searching for it usually does the trick.

I’m not a gynecologist, but Dr. Jen Gunter is and she isn’t a fan of garlic for yeast infections:

“My advice,” Dr. Gunter tweeted, “do not take medical advice from anyone recommending vaginal garlic for yeast or anything else.” There’s a big difference, she explains, between garlic demonstrating antifungal properties in a petri dish in a lab and garlic clearing up a pesky yeast infection. “Your vagina is not a dish of cells,” she wrote.

To be fair, many of the websites, naturopathic practices, and comment sections on parenting blogs don’t specifically recommend topical garlic use in a way that is likely to cause harm. They shouldn’t be recommending it at all, of course, but the other big problem is that most don’t specifically recommend against the harmful ways of doing it either. So parents and caregivers are left up to their own devices to figure it out, and unfortunately some end up figuring that if a little is good, a lot must be even better. It isn’t.

Garlic contains many chemicals that can cause physical reactions in the human body, some potentially beneficial and others decidedly not. It is widely known, for example, that some people can develop a topical allergy to garlic, which is not uncommonly seen on the hands of chefs and home cooks working with raw garlic. Diallyl disulfide, allyl propyl disulfide, and allicin are the chemicals in garlic considered to the be the likely culprits when it comes to these allergic reactions.

Diallyl disulfide, particularly when the skin is exposed for several hours or longer and held tight by some kind of occlusive wrap, can cause an irritant dermatitis as well. This can evolve into blisters and severe chemical burns, with young children being at the highest risk because of a thinner outermost protective layer of skin called the stratum corneum. So the younger the child, the shorter the exposure time needed to cause a chemical burn.

In the case of my patient, I can’t go into any specific details. But their presentation was consistent with the handful of case reports of severe garlic burns that have been published, the first being in 1987. When the area of involved skin is large, patients with severe burns regardless of the cause require care in a specialized burn unit where expert attention can be paid to maintaining hemodynamic stability, preventing secondary infections, treating pain, and improving long-term cosmetic outcomes.

The bottom line here is that there is not compelling evidence to support the use of garlic for any medicinal purpose. When taken systemically in the form of a pill, or even applied topically for a few minutes here and there, garlic is pretty safe. Still, a rational assessment of the benefits and the potential risks isn’t favorable. I recommend sticking to culinary use.

Author

  • Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.

Posted by Clay Jones

Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.