Most of the time warts are identified by looking for irregularities, lumps, bumps, roughness of the skin, or skin color changes.
Most of the time the diagnosis will be clear to a doctor experienced with this condition.
Applying 5% acetic acid or vinegar to the skin or cervix can highlight irregularities and different skin thicknesses that make it suspicious for warts. This produces white patches in the skin in about five minutes because of the change in surface quality, but is not a change specific for HPV infection.
Biopsy of the skin may be performed if:
The diagnosis is uncertain.
Warts not responding to standard therapy.
The condition worsens during therapy.
The patient's immune system is compromised.
The warts are pigmented, bleeding, ulcerated or firm, a possible sign of precancer.