Liquid nitrogen cryotherapy of common warts: cryo-spray vs. cotton wool bud: reply from authors

Abstract

Sir, We would like to thank Dr Kuwahara for his comments on our study. We have shown that liquid nitrogen is equally effective in treating common warts when applied either with a cryo‐spray or a cotton wool bud (CWB).1 Prior to our study,␣existing data relating to the response to cryotherapy were virtually all derived from the use of a CWB as the applicator.2–4 Cryo‐spray guns have been in common use for many years. The liquid nitrogen is kept in a closed flask under pressure and has a safety‐valve mechanism. They have a variety of tips and attachments to control the volume and direction of spray. We would agree with Dr Kuwahara that the cryo‐spray gun is quite elegant and easy to use. Application of liquid nitrogen with a CWB is also quite easy to master, although not so elegant. When treating young children, the appearance and sound of the cryo‐spray can be quite intimidating, and the CWB method may be preferred.