Liquid nitrogen is often used to destroy common skin lesions such as pre-cancerous actinic keratosis and benign lesions such as warts.
Blistering is a common side effect of liquid nitrogen treatments. Usually the blister will fill with clear fluid but sometimes the blister can fill with blood.
Liquid nitrogen is extremely cold (-391 degrees Fahrenheit or -192 degree Celsius). Contacting it to the skin causes skin cells to die. This is the reason it is effective when used to treat lesions like actinic keratoses (precancerous lesions) and warts. However, the local death of skin cells sometimes leads to the development of blisters.
The roof of a blister should not be peeled off since it acts as a natural protective dressing for the skin.
Treatment of the blister requires regular and frequent application of emollients such as petrolatum ointment. In addition, topical antibiotics may be added by a health professional to prevent infection.
In some cases, a heath professional may drain a blister if it becomes very painful.