Using liquid nitrogen to remove warts: what to know

Liquid nitrogen is an extremely cold material used in cryotherapy to freeze selected tissue. For a wart, a clinician identifies the lesion and applies the treatment in a controlled way. The area may sting, feel numb, or become red; a blister or crust can form as the treated tissue heals. The wart may need more than one session, depending on its site, thickness, and response.

A growth that looks like a wart may instead be a corn, callus, mole, or another lesion. Freezing an uncertain lesion at home can delay the correct diagnosis and may cause a burn, infection, scarring, or a lasting change in skin colour.

Have the lesion examined before treatment, especially if it bleeds, changes, hurts without pressure, or sits on the face, genitals, or near a nail. Do not put liquid nitrogen from an industrial or non-medical source on skin. After clinician-directed cryotherapy, keep the area clean, avoid picking a blister or crust, and follow the wound-care instructions provided.

Pain relief, dressing changes, or protection from friction may be advised for a treated foot or hand. People with poor circulation, reduced sensation, diabetes, immune suppression, or a history of troublesome scarring should mention this before freezing is considered.

Contact the treating clinician if pain is worsening, redness spreads, drainage becomes cloudy or foul-smelling, fever develops, or the wound is not healing as expected. Seek urgent help for rapidly increasing swelling, severe pain, or signs of a serious allergic or systemic reaction. A persistent or changing lesion needs reassessment rather than repeated freezing.

Ask whether the growth is suitable for cryotherapy, how it will be protected during healing, and what alternatives are available if it returns. Ask how your medical conditions or medicines could affect wound healing.