CRYOTHERAPY is often recommended for the treatment of actinic and seborrheic keratoses. Its use with liquid nitrogen has been popular, yet often is inconvenient, expensive or unavailable.
With the conventional use of solidified carbon dioxide (Dry Ice), an undesirable amount of post-treatment swelling is a disadvantage. This swelling develops probably because most physicians apply a pencil-like piece of Dry Ice and use firm pressure. This makes it difficult to confine application to the area to be treated, especially if the tissue is soft. If the surface of the lesion is irregular, application usually is uneven. Penetration to deep areas is difficult because the area already frozen insulates the tissue beneath it.
These disadvantages may be avoided by dipping a pointed piece of Dry Ice in acetone, allowing a drop to form on the point, and then applying the drop to the area to be treated, using no pressure.