Flat warts are caused by certain strains of the human papillovirus, or HPV. Other HPV strains are responsible for genital, plantar and other types of warts. You can usually identify flat warts by their flat-topped and smooth appearance, and by the fact that they rarely appear alone and tend to cluster together. The Mayo Clinic notes that flat warts mostly affect children and adolescents, and that the methods to remove them are similar to the methods used to remove other warts.
Wait
The simplest, though not always the most desirable, method of removing flat warts is to do nothing and let time take care of them. Warts.org and other sources note that the body's immune system will fight off the HPV infection within a few months and that the flat warts should go away on their own even if you do nothing at all.
Medication
Over-the-counter anti-wart medications containing salicylic acid may prove effective. Various strengths are available, from 17 percent (liquids) to 40 percent (patches). Follow the manufacturer's instructions for the specific product, but generally these liquids and patches are applied daily to remove the warts layer by layer until they're gone. MedlinePlus, an online medical encyclopedia from the National Institutes of Health, warns not to use this remedy for flat warts on the face.
Cryotherapy
Cryotherapy usually works faster than calicylic acid, and uses extremely low temperatures to literally freeze the warts away using liquid nitrogen. Though performed exclusively by doctors and dermatologist in the past, today there are over-the-counter cryotherapy products such as CompoundW Freeze Off, Dr. Scholl's Freeze Away and Wartner Original Freezing Wart Remover. These will need to be applied according the manufacturer's instructions until the wart tissue dies and the wart sloughs off. Again, avoid using this remedy on the face.
