Of all the known ways to get a acanthamoeba infection, nasal rinsing was the most likely in the man’s case. The man had nasal polyps and used sinus rinses to relieve his symptoms. However, his symptoms did not start in his nasal passages, but in his legs. There, red nodules formed and progressed to develop dark centers. Some turned into deep ulcers, while others became necrotic and turned into black scabs. Then it began to erupt on his trunk, arms and neck.
Catching a murderer
Before his transfer to Yale, doctors elsewhere attempted to identify the mysterious cause, performing multiple biopsies of his diseased skin. Tests were negative for bacterial or fungal pathogens. But they showed that their blood vessels were inflamed and filled with clumps of immune cells. Doctors were concerned that his immune system was attacking his blood vessels, causing necrotic lesions. He was then prescribed immunosuppressive medications. But his condition only worsened and the injuries only progressed. When he arrived at Yale, he had a fever and elevated heart rate, and appeared frail. I had lost 16 pounds and was sleepy and confused. He was covered in injuries.
Yale doctors noted that the injuries began after he returned from Florida, where he spent the winters. While there, he was exposed to red tide (caused by algae) while cleaning up after a hurricane. Otherwise, he had a medical history of nasal polyps and asthma, which he treated with a monoclonal antibody drug, dupilumab. As his lesions progressed, they redid a skin biopsy, this time finding cells that looked like amoebae. Confirmed DNA test acanthamoeba.
Doctors quickly put him on a five-drug regimen recommended for such infections by the Centers for Disease Control and Prevention, but he continued to deteriorate. They then sought and obtained approval from the Food and Drug Administration for a single-patient experimental trial of an antibiotic (nitroxoline) that had demonstrated success in treating a different amoeba in another patient. Once doctors started it on the man, it seemed to work. His fever briefly went down, some of his lesions improved, and no new ones formed.
