said Marla N. Jahnke, MD, of the Henry Ford Health System, Detroit, and her associates.
It is important to be careful when applying or handling cantharidin near the eyes, they noted. Also, parents must be counseled about possible side effects such as painful blistering, dyspigmentation, scarring, and itching, and that multiple treatment sessions may be needed.
The researchers did a retrospective chart review on patients under age 18 years treated with a cantharidin 0.7% solution between March 2013 and March 2014 at their institution, and performed a telephone survey to collect treatment outcomes from caregivers. Of the 62 caregivers contacted, the pediatric patients’ median age was 5 years (range 1.7-13), and 45% of the patients were white, 26% were black, 20% were Middle Eastern, 6% were Latino, and 3% were Asian, Pacific Islander, or Indian.
After cantharidin treatment, the caregivers most often described temporary discoloration (18%), severe blistering (10%), and pain that was excessive or greater than the caregiver expected (10%). Other outcomes described included itching (8%), scarring (6%), irritation (5%), bleeding (3%), and spreading of lesions (2%).
“Two patients returned to the office within 1 week of treatment because of excessive localized blistering that healed without long-term complications when topical emollients were used. ... Caregivers often could not confirm that they had washed off the cantharidin as recommended (1.5-2 hours after in-office application),” Dr. Jahnke and her associates noted in a research letter, which was published in the Journal of the American Academy of Dermatology.
Treatment satisfaction was high, with 94% of caregivers saying they would request cantharidin again if molluscum contagiosum were to recur on the child’s face, and 92% saying they would recommend it to others whose children had facial molluscum contagiosum. On a scale of 1 to 10, the average treatment satisfaction score was 8.7. The caregivers said that cantharidin was well tolerated by their children because it was painless when applied. The need for multiple office visits was the biggest complaint, the researchers revealed.
SOURCE: J Am Acad Dermatol. 2018 Jan. doi: 10.1016/j.jaad.2017.09.006.