Cryotherapy for actinic keratosis (AK) may be transiently painful for some patients but many experience little or no pain, according to an Irish study.
It found that cryotherapy caused moderate to severe pain in a significant minority of patients (46.3%). However the pain was short lived for most patients with only about 10% reporting persisting pain at 10 minutes and at 3-hour and 24 hour follow-ups.
The study, published in a Letter to the Editor of the British Journal of Dermatology, compared patient-reported pain at several time points before and after standard cryotherapy treatment in 95 adults.
It found just over half of patients (54.7%) reported mild or no pain immediately post cryotherapy.
The proportion of those patients reporting pain increased to 86.3% at 10 minutes before resolving for most patients. About 70% of patients said their pain was fully resolved at 3 hours and 76.4% by 24 hours.
“There was no correlation seen between pain scores and number or size of areas treated, skin type, AK grade or body site,” the authors noted.
And significantly more women than men reported ‘no immediate pain’, suggesting that women have a higher pain threshold for cryotherapy.
“This result is contrary to some studies that have examined the impact of sex on pain tolerance and thresholds suggesting that men have a higher pain threshold than women for experimentally induced pain,” they said
The authors said clinicians were aware that patients could experience pain after cryotherapy and that there was interindividual variability in the duration and intensity of pain.
“This study acknowledges the immediate moderate-to-severe pain experienced by a significant percentage of patients, but found that over half of patients report – at most – mild pain with cryotherapy. Additionally, 90% of the time, significant pain has largely resolved within 10 min.”
They concluded that cryotherapy remains the gold standard lesion-directed therapy for AK.
However documenting immediate and delayed pain associated with cryotherapy will facilitate more informed consent and comparisons with other therapies as they become available.
The study follows a call for RCTs to compare the clinical efficacy and patient acceptability of microwave treatment versus cryotherapy.