The key clues are highly suggestive that a follicular eruption in a child on targeted anticancer therapy is caused by the drug and not something else are the eruption’s symmetric distribution, that it’s truly follicular upon close inspection, and the timing: The eruption typically begins 2-3 weeks after initiation of therapy or within a week after a dose escalation.
Anti-inflammatory agents are the treatment mainstay. Treatment of the cutaneous eruption often is successful without need to discontinue the patient’s MAPK inhibitor.
“Even though some of these eruptions look comedonal, they’re not. It’s not a follicular plugging disorder, it’s an inflammatory condition. Topical steroids, oral tetracyclines, and dilute bleach baths all work pretty well. I haven’t had good experiences with keratolytics like tretinoin cream and benzoyl peroxide; they’re less effective. Dose reduction is the last resort for these patients. Often they are very sick. They need the drug and I think the last thing we want to do is take them off it,” Dr. Huang said.
She has observed that prepubertal children are more likely to have an eczematous reaction to their targeted anticancer therapy than a follicular eruption.