Warts
What Are Warts? What Causes Them?
Warts are small, firm growths on the skin with a rough texture. They’re caused by a virus called HPV (human papillomavirus). Since they arise from a virus, they’re contagious. You get them from someone else who has warts if there’s already trauma to the skin. This often happens in daycares, schools, and swimming centers. A child can also spread warts from one spot on their body to another via scratching, and this can sometimes cause warts to appear in clusters or a line.
What Do They Look Like?
It depends! They typically appear flesh-colored, grey, or yellow. You’ll usually see them in school-aged children and adolescents, most often on the hands, feet, around the fingernails and toenails, and on the knees (though you can also find them in other locations). In terms of the shape, there are five main types of warts, each with a different appearance.
Common: These are rough, raised and dome-shaped. They’re usually on the hands (including fingernails and toenails), and are more common in nail-biters due to the associated skin tears and trauma.
Plantar: These are located on the soles of the feet and cause discomfort with walking (e.g., feeling like a pebble is constantly stuck in your child’s shoe). They often have overlying and surrounding skin changes (rough, dry, and yellow or discolored skin). They can grow large.
Flat: These are flat and small, and tend to cluster. You’ll see them often on the forehead, cheeks, and skin, though they can show up anywhere.
Filiform: These will have “finger-like” projections, and often seem floppier and fleshier than the typical firm and flat wart. They’re more common on the face.
Are They Harmful? Do They Need To Be Treated?
They’re harmless, and it’s fine to leave them alone. However, they can get uncomfortable or cause cosmetic concerns, which is when we treat! There’s a few over-the-counter treatment options you can trial at home, and if those aren’t successful, see your PCP for additional management options.
Salicylic Acid: This is available over the counter, with the most familiar brand name being “Compound W.” Their products are available as solutions with tops that have an applicator that functions similar to a Q-Tip, or as medicated bandages for more troublesome areas like the foot. There are two main concentrations (17% and 40%).
17%: Ideal for arms, legs, knees, torso, back. Applied daily.
40%: Meant for palms and soles, often in bandage form and changed every 48 hours.
Application: Take a 10-15 minute shower and use an emory board or pumice stone to remove dead layers of the wart. After, pat dry the skin and apply the medication to the wart itself. It’s okay to leave it slightly damp, since this allows more effective absorption of the treatment. The recommended duration is at least 6-8 weeks, though it may take longer. Avoid these products on the face and genitals, since that skin is more sensitive (salicylic acid face washes and creams used for acne are typically a much lower concentration).
Duct Tape: This doesn’t have as much evidence to support it. However, it’s generally harmless to try! You would still wet the wart, use an emory board to remove dead skin, then apply the duct tape afterwards. Change the duct tape weekly for 6-8 weeks. You can also combine this method with salicylic acid.
Cryotherapy: In certain locations, cryotherapy is a great option. It’s essentially “freeze therapy,” where a very cold solution (usually liquid nitrogen) is applied via a spray can to the top layers of the wart. This creates a blister around the wart, and the dead skin sloughs off soon afterwards. This treatment is applied every 2-3 weeks until the wart is healed, and usually takes 2-4 sessions to see results. The side effects are local, such as bleeding or skin irritation. Most PCPs offer this, though if not, any Dermatologist should.
Note: After cryotherapy, once the blister has peeled, you can use Salicylic Acid as per above between cryotherapy sessions to help expedite healing.
Cantharidin: This is usually applied by Dermatologists. It causes blistering deep in the skin, which breaks the connection between the wart and the skin that it’s attached to. It usually only requires one treatment, does not cause discomfort, and doesn’t leave scarring.
Cauterization & Curettage: In cautery, a specialized tool is used that allows electricity to “burn” off layers of the wart. In curettage, dead skin layers of the wart are scraped off or the wart itself is cut off using a sharp tool. These techniques are often used together, and usually with local anesthesia. Side effects include discomfort and scarring.
Excision: Some warts can be surgically removed, though this tends to be reserved for specific locations due to scarring risk.
If warts are causing pain, if there are multiple, or if they are located on the face or genitals, seek help from your PCP or a Dermatologist.
How Long Do They Take To Go Away?
It can take months to years for warts to fully resolve. The more warts there are and the larger they are, the longer it will take. However, they tend to go away on their own eventually, so don’t worry if it feels like you’re not making headway with at-home measures.
How Can I Prevent Warts?
Since they’re transferred through contact, the easiest ways to avoid spreading warts are washing hands frequently, avoiding scratching or picking at warts, and wearing sandals or shoes in public setting (such as pools) rather than going barefoot.
