Articles - Warts

  • ›  

What's up with Warts?

"...treatments are usually only 70-80 percent effective... "

Paul Dunn, MD
Advanced Dermatology & Skin Surgery
Board Certified Dermatologist, FAAD
Associate Clinical Professor, University of Washington

Paul Dunn, MD

Warts are skin colored, rough growths that commonly develop on the skin.  They can grow anywhere on the body but are most common on the hands, feet, and knees. They are most common in children, but are seen at any age. 

Warts, also known as verruca are caused by the human papillomavirus (HPV).  The fact that they are caused by a virus means they can spread and can be contagious.  There are multiple different HPV types associated with different types of warts. These include common warts, plantar warts, flat warts, genital warts, as well as others. Some common growths on the skin that are often confused with warts include calluses, skin tags, seborrheic keratoses, and others. 

Since warts have an infectious etiology, treatment can be challenging.  There is no specific antiviral therapy available to cure HPV.  Therefore, treatment is focused primarily on destruction or sometimes immunotherapy or chemotherapy.  Fortunately, common warts can regress spontaneously, but that is most common in children. 

Cryotherapy with liquid nitrogen is the most common office treatment, but is not tolerated well by children.  Over-the-counter salicylic acid treatment can be helpful also, but requires a lot of compliance over months of treatment. 

Warts can also be treated in the office with topical agents that induce blistering such as cantharidin or types of acids.  Injections with immunomodulatory agents or a type of chemotherapy can also be used for resistant lesions.  The common goal with all of these treatments is to not only induce some type of destruction or reaction, but to also induce an immune response to suppress the virus.

Unfortunately, not all treatments are effective in every individual.  Generally, since individual treatments are usually only 70-80 percent effective, it may require trying a different treatment after one fails.  Warts are benign growths so if the lesions aren’t bothersome then they don’t need to be treated. 

By Paul Dunn, MD