Liquid Nitrogen and Nitrous Oxide in Cryotherapy: A Complementary Approach for Dermatology

Cryotherapy is one of the most versatile tools in dermatology, with applications ranging from common benign lesions to certain precancerous conditions. While liquid nitrogen (LN₂) has long been the gold standard, portable nitrous oxide (N₂O) devices such as the FrostAway™ Cryotherapy Pen are expanding how and where cryotherapy can be delivered.

Rather than replacing one another, each offers unique strengths. Together, they allow for a more tailored, patient-focused approach.

How They Work

Both liquid nitrogen and nitrous oxide destroy targeted tissue by rapidly cooling it, causing ice crystal formation within cells, blockage of blood supply, and eventual cell death.

• Liquid Nitrogen: Boils at −196 °C (−320 °F) and produces a rapid, deep freeze that can reach lethal temperatures for most cells within seconds.
• Nitrous Oxide: Boils at −89 °C (−128 °F), still cold enough to destroy many lesion types but in a more controlled and localized way.

Liquid Nitrogen: Power and Versatility.

Liquid nitrogen has decades of proven efficacy and remains indispensable for:

• Thick, extensive, or multiple lesions
• Premalignant and select superficial malignant lesions
• Rapid treatment of large treatment areas

It can reach skin temperatures near −60 °C (−76 °F) in just a few seconds, allowing deep penetration and high clearance rates. However, it requires insulated storage tanks, constant replenishment, and skilled handling to avoid overspray or injury to surrounding tissue.

Pain, blistering, and pigment changes can occur, which may limit its use in cosmetically sensitive areas or with pediatric patients.

Nitrous Oxide: Precision and Portability

Nitrous oxide cryotherapy devices deliver a pressurized jet of gas through fine applicator tips, allowing millimeter-level accuracy. They are especially well-suited for:

• Lesions on the face, eyelids, ears, and other delicate areas
• Pediatric or anxious patients
• Mobile clinics or practices without convenient LN₂ access
  
  

Treatment is generally well tolerated, with minimal overspray and reduced risk to surrounding skin. The device is self-contained and requires no large tanks or complex storage.

While N₂O is not as cold as LN₂, it remains effective for many benign lesions. Thicker lesions may require longer freeze times or multiple applications.

Choosing the Right Tool

In practice, LN₂ and N₂O work best as complementary tools:

• Liquid Nitrogen: Best for high-volume sessions, thicker or aggressive lesions, and cases where depth of freeze is essential.
• Nitrous Oxide: Best for precision work, cosmetically sensitive areas, and situations where patient comfort is a priority.

Incorporating both cryotherapy modalities into a dermatology practice allows clinicians to match the treatment to the lesion and the patient. Liquid nitrogen delivers unmatched freezing power, while nitrous oxide devices provide portability, precision, and a gentler approach for delicate cases.

As with any in-office treatment, the choice of cryotherapy method should be guided by the clinician’s professional judgment, patient history, and specific lesion characteristics. These tools are intended for use by licensed medical professionals who can assess suitability, determine the safest approach, and manage any potential complications.

The FrostAway™ Pen offers the benefits of nitrous oxide cryotherapy in an accessible, controlled format that complements your practice’s existing cryosurgery setups, expanding treatment possibilities without compromising effectiveness.

Sources

• Clebak KT, et al. Cutaneous Cryosurgery for Common Skin Conditions. Am Fam Physician. 2020;101(7):399-406.
• S. FDA 510(k) Summary for CryoIQ Pro Liquid Nitrous Oxide Device (Example).
• Clebak KT, et al. Am Fam Physician. 2020;101(7):399-406.
• Erdmann SAB, Wokes J. Skin thermal recovery following cryotherapy: LN₂ vs N₂O. Clin Exp Dermatol. 2023.
• DermNet NZ. Cryotherapy: Uses, Cautions, and Aftercare. Updated Aug 2022.
• FrostAway Cryotherapy Pen – Product Description. Delasco.