Subcutaneous Emphysema Resulting from Liquid Nitrogen Spray

The document reports a case of subcutaneous emphysema (SE) in a 79-year-old Caucasian woman following the use of liquid nitrogen spray on a curetted hypertrophic actinic keratosis on her forearm. SE, which is the presence of gas within subcutaneous tissue, appeared instantly after the treatment and involved an area of approximately 10 cm with visible soft tissue swelling and palpable crepitus. The condition improved over 30 minutes and resolved by the following day. The document discusses that SE can result from various causes, including serious infections or trauma, but in this case, it was a benign and self-resolving complication of cryotherapy. The risk of SE is higher with cutaneous defects such as ulcerations, curettage procedures, and freshly closed wounds, especially in patients with frail, atrophic skin. Alternative methods such as using a cotton-tipped applicator or a cryoprobe, or utilizing pressure rings or cones when spraying open lesions, are suggested to minimize this risk. Other complications associated with liquid nitrogen are also mentioned, including blistering, bleeding, infection, dyspigmentation, hair loss, altered sensation, nerve damage, atrophy, and scarring.