Liquid Nitrogen Treatment (Cryotherapy) for Skin Growths


We use liquid nitrogen to remove abnormal (precancerous) and benign (noncancerous) skin growths, such as warts.

This treatment is known as cryotherapy or cryosurgery.

For skin growths, we apply liquid nitrogen to the skin with a spray canister or a cotton-tipped swab. Liquid nitrogen is extremely cold. You feel stinging or burning for a few minutes when we apply it. After it’s applied:

  • A blister forms where liquid nitrogen contacts your skin.
  • A scab forms over the blister. It usually falls off within 2 to 4 weeks.

Your skin may be tender for a few days after treatment. The area may be permanently scarred, and your skin color may be:

  • Lighter than normal (hypopigmentation)
  • Darker than normal (hyperpigmentation)

Why It Is Done

Skin care specialists (dermatologists) most often use liquid nitrogen to remove:

  • Precancerous growths from sun damage (actinic keratoses)
  • Irritated skin tags or other harmless (benign) growths (seborrheic keratoses)
  • Warts

How You Prepare

We usually treat surface skin problems in our clinics. Liquid nitrogen treatment takes only a few minutes. Usually, you won’t need special preparation.

You can take acetaminophen (Tylenol) about 30 minutes before your procedure to reduce discomfort, if you like.

How It Is Performed

We treat surface skin growths by applying liquid nitrogen to the top layer of the growths. We use a spray canister or a cotton-tipped swab.

The liquid nitrogen instantly freezes the growth and a small area of surrounding skin tissue.

You may feel a burning or stinging sensation while we apply it, and for a few minutes afterward.

Your skin will:

  • Look red and swollen around the growth.
  • Form a blister within 3 to 6 hours where we applied the liquid nitrogen.
  • Turn dark purple or black and possibly bleed a little during the blister stage.
  • Form a scab within 2 to 3 days, which falls off within 3 to 4 weeks.

The treated area may feel tender for a few days. You may need several liquid nitrogen treatments to completely remove an abnormal growth or tissue.

After Your Procedure

It’s best to leave your blister uncovered, unless we give you other instructions. If the area is tender, it’s okay to cover it with a bandage for a few days.

Follow your doctor’s instructions, which generally direct you to:

  • Let the scab fall off on its own. Don’t try to remove it. This helps avoid a scar or an infection.
  • Don’t soak the blister in water for at least 24 hours after your liquid nitrogen treatment. This means no long baths or swimming during this time.
  • Gently wash the area with mild soap and warm water, if you like.
  • Take an over-the-counter pain reliever, such as acetaminophen (Tylenol) if the area is tender or painful.

Be sure to wear sunscreen or clothing to protect the blistered area from the sun. Continue this after the scab falls off. This helps the treatment area heal properly.

When to Call Us

Call us if:

  • You continue to have discomfort, pain, or burning.
  • The blister or scab doesn’t fall off within 4 weeks.

Schedule an appointment right away if you have signs of infection, such as:

  • Fever
  • Swelling, tenderness, or pus oozing from the treatment site

Be sure to let us know if the skin growth is still there 4 weeks after your first treatment. Some growths (such as warts or precancerous areas) may require repeat liquid nitrogen treatment.

If you have an emergency medical condition, call 911 or go to the nearest hospital. An emergency medical condition is any of the following:
(1) a medical condition that manifests itself by acute symptoms of sufficient severity (including severe pain) such that you could reasonably expect the absence of immediate medical attention to result in serious jeopardy to your health or body functions or organs; (2) active labor when there isn't enough time for safe transfer to a Plan hospital (or designated hospital) before delivery, or if transfer poses a threat to your (or your unborn child's) health and safety, or (3) a mental disorder that manifests itself by acute symptoms of sufficient severity such that either you are an immediate danger to yourself or others, or you are not immediately able to provide for, or use, food, shelter, or clothing, due to the mental disorder.

This information is not intended to diagnose health problems or to take the place of specific medical advice or care you receive from your physician or other health care professional. If you have persistent health problems, or if you have additional questions, please consult with your doctor. If you have questions or need more information about your medication, please speak to your pharmacist. Kaiser Permanente does not endorse the medications or products mentioned. Any trade names listed are for easy identification only.