NEW ORLEANS - Any physician who's not regularly using topical 5% 5-fluorouracil cream for treatment of warts in children is missing out on a therapy that’s singularly safe, well tolerated, and effective.
That's the considered opinion of Dr. Bari B. Cunningham, who not only uses this therapy on a daily basis in her Encinitas, Calif., pediatric dermatology practice, but was also senior author of an open-label study demonstrating its benefits.
“I would strongly urge you to consider this therapy. This is a pearl that will make a major impact on the pediatric patients you see every day,” she promised at the annual meeting of the American Academy of Dermatology.
From her standpoint, the most important thing about topical 5-FU cream for warts in kids is its safety, since this therapy does after all involve off-label use of a potent drug in little children. Reassuringly, in her 39-patient study there were no detectable blood levels of 5-FU during or after 6 weeks of therapy.
From the perspective of the patient and family, however, the big appeal is the therapy's ease and tolerability.
“When you’re a dermatologist dealing with kids you really need to look for alternatives to the painful therapies that we currently use. If you have child with extensive warts you really can't be considering painful treatment options such as liquid nitrogen or intralesional bleomycin. That's just not going to cut it, and that family is never going to come back to you again. It’s not humane to expect a child to sit through painful treatments for something that benign,” explained Dr. Cunningham.
The 39 children in her study all had at least two hand warts to which topical 5-FU cream was applied once or twice daily under occlusion for 6 weeks. Eighty-eight percent of patients were significantly improved after 6 weeks, and 41% had complete resolution of at least one wart. The treatment response didn't differ between once- and twice-daily therapy. Tolerability and patient satisfaction were excellent. At 6 months of follow-up, 87% of complete responders had no wart recurrences (Pediatr. Dermatol. 2009;26:279-85).
Since publication of her study, Dr. Cunningham has modified how she uses topical 5-FU cream for pediatric warts. The drug is applied at night under duct tape occlusion, alternating with salicylic acid under duct tape occlusion every second night because she believes the two agents are complementary. The duct tape is removed each morning and the wart is left uncovered and untreated during the day.
“I only do this for a month at a time because that's really all I ever need. If this medicine is going to work – and it usually does – it works fast,” she said.
The ideal warts for this form of therapy are single and rapidly growing. “The ones that are doubling in size every couple of weeks like they've got a mind of their own, those are the perfect ones to treat with topical 5-FU because 5-FU is going to impair cell division and really shut that wart down,” Dr. Cunningham continued.
She offered a few cautionary notes: Don't use this therapy on periungual warts; it will result in serious onycholysis, and the nail will fall off. Avoid treating warts on the face. In order to prevent systemic absorption, don’t use topical 5-FU cream in orally fixated thumb suckers. And make sure to keep the medication out of reach of the family dog. Dogs have a paradoxical toxic reaction to topical 5-FU. There are dozens of reports of dog fatalities in the veterinary literature, Dr. Cunningham said.
She declared having no relevant financial interests.