[Cryotherapy with nitrous oxide in primary care]

To study the efficacy, tolerance and safety in primary care of the cryotherapy technique using nitrous oxide. Design. Descriptive, observational and transversal study.

Mariñamansa-A Cuña Health Centre, Ourense.

All the patients who consulted for cutaneous lesions caused by cryotherapy between March and April 2000 (n=130).

Age, sex, diagnosis, location, size of lesion, duration of application of the cryogenic agent, previous treatment, side-effects observed, and evolution of the lesion.

Mean age was 36.65 (95% CI, 32.57-40.74), of whom 53.8% (95% CI, 44.80-62.50) were women. The most common lesions were common warts (68.5%), actinic Keratosis (12.3%) and plantar warts (7.7%). We found that most lesions were located on an upper limb (50.8%). The mean size of lesions was 8.65 mm2 (95% CI, 4.50-12.80). 69.7% of warts were scraped prior to cryotherapy; and 16.2% received prior keratolysis. We found no side-effects in 32.3% of the patients; the commonest side-effect detected was blisters. Mean number of cryotherapy sessions was 2.82 (95% CI, 2.39-3.29). The technique was tolerated well in 83.8% of cases. We found total cure in 87.7%. Most of the cutaneous lesions that failed were common warts.

Nitrous oxide is effective in most lesions caused by cryotherapy. The technique is tolerated well, can be handled easily and can be used in primary care.