Pros and Cons of Pediatric Wart Therapy Weighed
Start use of squaric acid dibutyl ester by applying a 2% solution to a small, quarter-size area of normal skin on the forearm and wait 2 weeks to check for sensitization, she recommended.
If none occurs, parents could apply a 0.2% solution to warts 37 times per week.
An intralesional immunotherapy, Candida antigen injection, is more painful.
The injections are thought to be less painful than cryotherapy but still too painful for young children, she said.
Some teenagers may tolerate it. It seems to be effective and induces immunity but is expensive and can cause itching as well as pain at the treatment site.
▸ Other off-label therapies. Among other off-label therapies, topical 5-fluorouracil can be applied to warts daily for 6 weeks.
"I use it a fair amount in older kids and teens, especially if they're too busy to come back for visits," Dr. Soohoo said. It is an FDA Pregnancy Category X and is available in compounded formulations by mail order from pharmacies.
Topical retinoic acid has been applied to flat warts on the face for up to 8 weeks of daily treatment but can cause local skin irritation, she said.
A study of pulsed dye laser therapy in 56 children found no support for its use as first-line therapy for pediatric warts (J. Am. Acad. Dermatol. 2007;56:20510).
Duct tape does not work as monotherapy but may boost the efficacy of other topical therapies when used in combination, she concluded.
Dr. Soohoo reported no conflicts of interest.
Treatment Choice Decided by Age, Type of Wart
Dr. Soohoo's preferred wart treatments depend on the patient's age and type of warts, as shown in the following:
▸ Common and plantar warts. For children under age 9 years, salicylic acid is first-line therapy, "but usually by the time parents see me, they've tried this," she said. Cantharidin plus Aldara are her next choice, with squaric acid a "distant third" choice.
For older children, salicylic acid plus liquid nitrogen would be her first choice for therapy, "but often they're too busy to come back" for repeat treatments, in which case she opts for topical 5-fluorouracil instead. Candida antigen injections are a distant third choice for these warts.
▸ Flat warts. Dr. Soohoo would pick tretinoin cream first, with light cryotherapy as her second choice. Sometimes Aldara can be used on these warts, "but with caution," she said.
▸ Periungual warts. Cryotherapy plus salicylic acid comprise first-line treatment for periungual warts in Dr. Soohoo's office. Second in line is topical 5-fluorouracil. Her third option is cantharidin applied in the office plus Aldara applied at home. Rarely, she resorts to Candida antigen injections or squaric acid for these warts.
