There’s an old saying in medicine: If you hear hoof beats, think of horses—not zebras. In other words, do not assume that something rare or exotic is causing a patient’s symptoms when a commonplace explanation is much more likely.
But even old medical proverbs are wrong sometimes, as Cristina LaPointe found out last year. She likes to joke that her infant son Leo is an “albino zebra.”
“My sister would send me pictures of albino zebras; we needed that humor,” she said.
In November 2016, doctors diagnosed Leo with pyoderma gangrenosum, an extremely rare and painful ulcerating skin condition. Only a handful of cases have been reported nationwide in infants under the age of one. Leo was 9 months old at the time.
“This may be only the fifth pyoderma gangrenosum diagnosis in someone his age,” said University of Minnesota Health Pediatric Dermatologist Sheilagh Maguiness, MD, who treated Leo.
Because of its medical obscurity, pyoderma gangrenosum—or PG—can be very difficult to diagnose. When Cristina first brought Leo to his primary provider, the doctor thought the blister forming in Leo’s diaper area was a chemical burn. Leo’s wound continued to grow, eventually exposing the underlying muscle in parts of his diaper area.
Concerned, Leo’s doctor referred him to Hennepin County Medical Center for debridement and a skin graft. During debridement, surgeons remove damaged tissue from the wound site.
Before the debridement, dermatologists performed a biopsy. The test revealed that the wound was not the result of a chemical burn. Instead, physicians identified it as pyoderma gangrenosum. Leo was transferred to the University of Minnesota Masonic Children’s Hospital, where Maguiness and her colleagues, including Pediatric Rheumatologist Mona Riskalla, MD, began treating him with a combination of steroids and immunosuppressants.
Dermatologists often fear that PG will be misdiagnosed and that patients will be taken to the operating room for a debridement, Maguiness said.
“That can actually exacerbate the skin and make the condition worse,” she said. “We were lucky to have healthy collaboration between specialties.”
Today, Leo is a happy and healthy 1-year-old who’s walking and achieving all of his growth milestones. After the diagnosis, Leo and his family stayed at Masonic for 16 days before Leo was healthy enough to be discharged. Cristina and her husband, who are both local middle school teachers, took leave from their jobs to care for Leo. After 50 days, his wound had healed.
“We jokingly say that we won a lottery that nobody wants to win,” Cristina said. “We had amazing care through it all. Masonic Children’s Hospital was such a good place for our family, and we came together as a family, too.”
Because pyoderma gangrenosum is so rare, Maguiness and her colleagues asked Cristina if they could use Leo’s case to educate other physicians, residents and medical students about the diagnosis and treatment of the condition. Cristina and her husband were happy to help.
“If others can learn from this, that’d be great,” Cristina said. “We’re educators. If Leo’s case can help educate other people about what worked well and what worked effectively, then we’re all for it.”
Doctors still aren’t certain what caused Leo’s condition. In adults, pyoderma gangrenosum is often a symptom of another underlying condition, such as rheumatoid arthritis or another systemic disease. In children, it often occurs as an isolated condition. Maguiness and her team tested Leo for possible genetic conditions, but the tests came back negative. Maguiness will continue to watch him closely in the coming years. For now, Leo is healthy.
“This case is so rare that I hope people can learn something from it,” Maguiness said. “The takeaway is that we shouldn’t get stuck on one diagnosis. Doctors should keep an open mind, should keep coming up with other possibilities and keep communicating with their colleagues. In the end, that approach was best for Leo.”