Common warts (verruca vulgaris) are more of a nuisance than a serious health problem, but they are interesting. There is a whole mythology surrounding their cause (touching toads?) and treatment (everything from banana peels to vitamin C). Many people believe they can be made to vanish by suggestion or hypnosis. I used to believe that too.
Every doctor has wart stories. Here are some of mine.
- A patient made an appointment to see me because he had a wart, but when he tried to show me his wart he discovered that it had vanished! Apparently, just making the appointment cured it.
- Another patient did have obvious warts and I prescribed the “wart medicine” that our pharmacy tech compounded, based on salicylic acid. He was out of one of the ingredients and had to ask my patient to return in a week. When she returned, her warts were already gone. The wart medicine apparently worked so well that you didn’t even have to use it!
- I worked with a dermatologist who used a colorful laminated card with a picture of a toad to stroke children’s warts, telling them it was a wart remover. In his experience, this would frequently make the wart vanish over the next few days. Was this ethical? Was he lying and deliberately deceiving patients, or could this be excused as playing make-believe to distract the child and improve his attitude about the wart?
He was certainly deceiving himself in thinking that this foolishness was actually effective based on his own uncontrolled observations. Hypnotists claim success in treating warts with direct suggestion: they say that prepubertal children respond almost without exception, although it is less effective in adults. I was taught that if a patient had multiple warts and you treated just one of them, the others would likely vanish too. This might sort of make sense if the treatment stimulated an immune response, but I haven’t seen any evidence to support it.
What can science tell us about warts?
A new review article in American Family Physician, “Treatment of Nongenital Cutaneous Warts” by Mulhem and Pinelis provides a thorough update of the current evidence.
Cutaneous warts are epidermal proliferations caused by over 100 types of human papillomavirus. They are spread person-to-person or by contact with contaminated objects. They are most common in children. Walking barefoot is a risk factor for plantar warts (warts on the sole of the foot that that have a different appearance due to being under pressure). Nail-biting, meat handling, and immunosuppression are also risk factors. 90% of renal transplant patients develop warts.
Warts are usually self-limited. Half resolve spontaneously in a year, two-thirds within two years. Watchful waiting is an option, but patients often want treatment because of discomfort or social stigma. Two treatments have been clearly proven effective by scientific studies: salicylic acid and freezing with liquid nitrogen. There is limited evidence for silver nitrate, topical fluorouracil, and topical zinc. There is little to no good evidence for cantharidin, dinitrochlorobenzene, oral cimetidine, oral zinc sulfate, podophyllin, propolis ointment, retinoids and topical garlic extract. A few years ago, duct tape was reported to work, but subsequent studies showed that it probably does not. Warts can also be surgically removed, and dermatologists can offer specialized treatments such as intralesional bleomycin and pulse dye laser.
I found it interesting that the AFP review didn’t even bother to mention hypnosis, suggestion, or CAM.
Salicylic acid preparations are available over the counter for self-treatment. They are well tolerated and produce a 73% cure rate in 6 to 12 weeks. Cryotherapy with liquid nitrogen is equally effective but is more expensive, requires multiple office visits, and can cause pain, blistering, pigment changes, and other complications (tendon or nerve damage, scarring), especially if used too aggressively. A combination of cryotherapy and salicylic acid may give the best results. If a treatment caused permanent scarring, that would be worse than the disease.
To take a page from Mark Crislip’s job description, the patient has the mindset “Me have wart. You cure wart. Me go home.” The health care provider can re-frame the issue as “You have wart. Me educate. You think. We discuss.” Since warts are benign and self-limited, the option of not treating should always be on the table.
What about CAM?
Warts provide a fertile field for CAM. Various CAM modalities (chiropractic, acupuncture, homeopathy, energy medicine, etc.) have been claimed to cure warts. Acupuncturists have claimed a 90% success rate in only 1-3 weeks. PubMed lists a recent article about treatment with “sparrow-pecking” moxibustion that sounds intriguing, but no abstract is available. When warts follow their natural history and resolve, CAM is happy to take the credit. When they fail to resolve, CAM can continue treatments and continue to generate income. It’s a cash cow and ideal CAM fodder. Since warts are so common, potential clients are plentiful.
I used to believe that warts could be wished away. Now that I am older and wiser, I think warts vanish because of the natural course of the disease, not because of suggestion. Observers have reached false conclusions due to the post hoc ergo propter hoc (correlation is not causation) fallacy. Warts that went away after suggestion didn’t go away because of suggestion. The many folk remedies, like banana peels, were perpetuated by similar errors in reasoning. No matter how much we wish mind-over-matter worked, warts can’t be wished away: that’s the truth, warts and all.
- Yes, But. The Annotated Atlantic. - November 7th, 2009 [November 7th, 2009]
- Health Insurance Benefit Costs by Region - November 8th, 2009 [November 8th, 2009]
- For an Operator, Please Press... - November 8th, 2009 [November 8th, 2009]
- Pollyanna With a Pen: Maine Governor Signs 18 New Health Care Bills into Law - November 8th, 2009 [November 8th, 2009]
- AMA Sounds the Alarm, Medicare Making Yet Another Attempt to Cut Reimbursement - November 8th, 2009 [November 8th, 2009]
- Mass Governor Asks Blue Cross to Keep Higher Employer Contribution - November 8th, 2009 [November 8th, 2009]
- Lifespan and Care New England Plan Monopoly (Again) - November 8th, 2009 [November 8th, 2009]
- Dirigo Health: Con Artists, Liars, and Thieves? - November 8th, 2009 [November 8th, 2009]
- New Orleans: Health Challenges - November 8th, 2009 [November 8th, 2009]
- August a Flurry of Activity - November 8th, 2009 [November 8th, 2009]
- Maine's Dirigo Health Savings One-Third of Original Estimate - November 8th, 2009 [November 8th, 2009]
- “Methodolatry”: My new favorite term for one of the shortcomings of evidence-based medicine - November 8th, 2009 [November 8th, 2009]
- Suzanne Somers’ Knockout: Dangerous misinformation about cancer (part 1) - November 8th, 2009 [November 8th, 2009]
- A science-based blog about GMO - November 8th, 2009 [November 8th, 2009]
- A Not-So-Split Decision - November 8th, 2009 [November 8th, 2009]
- Military Medicine in Iraq - November 8th, 2009 [November 8th, 2009]
- The effective wordsmithing of Amy Wallace - November 8th, 2009 [November 8th, 2009]
- A Science Lesson from a Homeopath and Behavioral Optometrist - November 8th, 2009 [November 8th, 2009]
- Join CFI in opposing funding mandates for quackery in health care reform - November 8th, 2009 [November 8th, 2009]
- Mainstreaming Science-Based Medicine: A Novel Approach - November 8th, 2009 [November 8th, 2009]
- Those who live in glass houses… - November 8th, 2009 [November 8th, 2009]
- J.B. Handley of the anti-vaccine group Generation Rescue: Misogynistic attacks on journalists who champion science - November 8th, 2009 [November 8th, 2009]
- When homeopaths attack medicine and physics - November 8th, 2009 [November 8th, 2009]
- The cancer screening kerfuffle erupts again: “Rethinking” screening for breast and prostate cancer - November 8th, 2009 [November 8th, 2009]
- All Medicines Are Poison! - November 8th, 2009 [November 8th, 2009]
- When Loud Wins: Will Your Tax Dollars Pay For Prayer? - November 8th, 2009 [November 8th, 2009]
- It’s All in Your Head - November 8th, 2009 [November 8th, 2009]
- The Skeptical O.B. joins the Science-Based Medicine crew - November 8th, 2009 [November 8th, 2009]
- The Tragic Death Toll of Homebirth - November 8th, 2009 [November 8th, 2009]
- What’s the right C-section rate? Higher than you think. - November 8th, 2009 [November 8th, 2009]
- Recombinant Human Antithrombin – Milking Nanny Goats for Big Bucks - December 13th, 2009 [December 13th, 2009]
- Does C-section increase the rate of neonatal death? - December 13th, 2009 [December 13th, 2009]
- Man in Coma 23 Years – Is He Really Conscious? - December 13th, 2009 [December 13th, 2009]
- Why Universal Hepatitis B Vaccination Isn’t Quite Universal - December 13th, 2009 [December 13th, 2009]
- Ontario naturopathic prescribing proposal is bad medicine - December 13th, 2009 [December 13th, 2009]
- Naturopaths and the anti-vaccine movement: Hijacking the law in service of pseudoscience - December 13th, 2009 [December 13th, 2009]
- The Institute for Science in Medicine enters the health care reform fray - December 13th, 2009 [December 13th, 2009]
- Neti pots – Ancient Ayurvedic Treatment Validated by Scientific Evidence - December 13th, 2009 [December 13th, 2009]
- Early Intervention for Autism - December 13th, 2009 [December 13th, 2009]
- A temporary reprieve from legislative madness - December 13th, 2009 [December 13th, 2009]
- A critique of the leading study of American homebirth - December 13th, 2009 [December 13th, 2009]
- Lose those holiday pounds - December 13th, 2009 [December 13th, 2009]
- Endocrine disruptors—the one true cause? - December 13th, 2009 [December 13th, 2009]
- Acupuncture for Chronic Prostatitis/Chronic Pelvic Pain Syndrome - December 13th, 2009 [December 13th, 2009]
- Evidence in Medicine: Experimental Studies - December 13th, 2009 [December 13th, 2009]
- Midwives and the assault on scientific evidence - December 13th, 2009 [December 13th, 2009]
- The Mammogram Post-Mortem - December 13th, 2009 [December 13th, 2009]
- An Influenza Recap: The End of the Second Wave - December 13th, 2009 [December 13th, 2009]
- The End of Chiropractic - December 13th, 2009 [December 13th, 2009]
- Cell phones and cancer again, or: Oh, no! My cell phone’s going to give me cancer! (revisited) - December 20th, 2009 [December 20th, 2009]
- Another wrinkle to the USPSTF mammogram guidelines kerfuffle: What about African-American women? - December 20th, 2009 [December 20th, 2009]
- Acupuncture, the P-Value Fallacy, and Honesty - December 20th, 2009 [December 20th, 2009]
- The One True Cause of All Disease - December 20th, 2009 [December 20th, 2009]
- Communicating with the Locked-In - December 20th, 2009 [December 20th, 2009]
- Are the benefits of breastfeeding oversold? - December 20th, 2009 [December 20th, 2009]
- Measles - December 20th, 2009 [December 20th, 2009]
- Radiation from medical imaging and cancer risk - December 21st, 2009 [December 21st, 2009]
- Multiple Sclerosis and Irrational Exuberance - December 21st, 2009 [December 21st, 2009]
- Medical Fun with Christmas Carols - December 22nd, 2009 [December 22nd, 2009]
- Lithium for ALS – Angioplasty for MS - December 23rd, 2009 [December 23rd, 2009]
- “Toxins”: the new evil humours - December 24th, 2009 [December 24th, 2009]
- 2009’s Top 5 Threats To Science In Medicine - December 24th, 2009 [December 24th, 2009]
- Buteyko Breathing Technique – Nothing to Hyperventilate About - December 26th, 2009 [December 26th, 2009]
- The Graston Technique – Inducing Microtrauma with Instruments - December 29th, 2009 [December 29th, 2009]
- The “pharma shill” gambit - December 29th, 2009 [December 29th, 2009]
- Ginkgo biloba – No Effect - December 30th, 2009 [December 30th, 2009]
- Oppose “Big Floss”; practice alternative dentistry - January 1st, 2010 [January 1st, 2010]
- Causation and Hill’s Criteria - January 3rd, 2010 [January 3rd, 2010]
- The life cycle of translational research - January 10th, 2010 [January 10th, 2010]
- The anti-vaccine movement strikes back against Dr. Paul Offit - January 10th, 2010 [January 10th, 2010]
- Osteoporosis Drugs: Good Medicine or Big Pharma Scam? - January 10th, 2010 [January 10th, 2010]
- Acupuncture for Hot Flashes - January 10th, 2010 [January 10th, 2010]
- The case for neonatal circumcision - January 10th, 2010 [January 10th, 2010]
- A victory for science-based medicine - January 10th, 2010 [January 10th, 2010]
- James Ray and testosterone replacement therapy (TRT) - January 10th, 2010 [January 10th, 2010]
- The Water Cure: Another Example of Self Deception and the “Lone Genius” - January 12th, 2010 [January 12th, 2010]
- Be careful what you wish for, Dr. Dossey, you just might get it - January 13th, 2010 [January 13th, 2010]
- You. You. Who are you calling a You You? - January 15th, 2010 [January 15th, 2010]
- The War on Salt - January 16th, 2010 [January 16th, 2010]
- Is breech vaginal delivery safe? - January 16th, 2010 [January 16th, 2010]