The 72-year-old woman carefully loosened the bandage she had wrapped around her thumb. As she gently revealed the injured finger, her daughter gasped. The top third of what should have been the fleshy part looked eaten away. The flesh that remained was black and hard. A foul odor emanated from the wound. “Yesterday I thought there was a dead mouse in my living room,” the woman told her daughter. “Then I realized it was my thumb.” She couldn’t do anything with that hand now, not even work in her garden. It was very upsetting.

Black Thumb

The daughter wondered: Was this gangrene? Was her mother going to lose her thumb? She took out her phone and snapped a picture of the digit. She and her mother’s internist worked in the same medical center in nearby Joplin, Mo., and he needed to know how serious this was.

The doctor had seen the rash before. The patient came to his office a few months back when her hands first swelled up. The next time he saw her, just a few weeks ago, the skin on her hands had red, painful blotches. But this was new, he told the daughter after seeing the pictures. He didn’t know what her mother had. After a moment of silence, he made his recommendation: She should take her mother to the Mayo Clinic in Rochester, Minn., nearly 600 miles away. “Don’t make an appointment,” he told her. Take her to the emergency room. They’d figure it out. He was sure of that.

On the Road

Early the next morning, mother, two friends and another daughter set off on the 10-hour, four-state trek north to the Mayo Clinic. By the time they arrived, the mother could barely walk to the door. In the waiting room, she suddenly began to shiver. She was so cold, she told her daughter. Her teeth chattered. She had a fever. To her daughter, she seemed disoriented and confused. Clearly they’d brought her in just in time.

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It was past midnight when the patient was admitted and settled into a hospital room. Dr. Daniel Partain, the doctor in training assigned to her care, introduced himself. Until recently, arthritis had been her biggest health problem, she explained. A few years earlier she started to see a rheumatologist, who told her she had something called psoriatic arthritis — an aggressive type of arthritis caused by the body’s immune system, which mistakenly attacks itself. Left untreated, this disease can destroy bone. He started her on strong immune-suppressing medicines, and she did feel better.

She’d been on those medicines for four years and was doing fine. Then, three months earlier, the swelling started — and the ugly red patches appeared all over her hands and arms. The joints didn’t hurt, but the rash did. The rheumatologist attributed it to a flare-up of her psoriatic arthritis and increased her immune-suppressing meds. When that didn’t help, he switched her to more powerful drugs. But her hands, especially her thumb, just got worse.

The woman told her story cheerfully enough, but it was clear to Partain that she was in pain. Her right hand lay mostly immobile on her lap, swollen and covered with red blotches. Her thumb was shockingly ugly, the raw flesh on the tip covered by a thick black scab. There were other areas of scaly, deep red skin on both her arms, but nowhere else.

The young doctor wasn’t sure what was going on. If arthritis was causing this rash and black thumb, then why weren’t her medications helping? Maybe she had an infection as well; because the meds she took suppressed her immune system, our most important defense against invading organisms, she was vulnerable to all kinds of bugs. Partain ordered antibiotics just in case. He asked that a rheumatologist and a dermatologist come by later that day. He gave the woman something for the pain, and then he went to see his next patient.

The Wisdom of Experience

In the morning, Dr. Ruth Bates, the senior resident on the team, listened with interest as her intern told her about this new patient. She praised him for his thoughtful approach. When they entered the room, the patient unwrapped the bandage to give the team a chance to see the lesion that brought them together. They examined the patient and then left, promising to come back after lunch.

As soon as they were in the hall, Bates turned to her intern. “I think I know what this is,” she told him. “I’ve seen it before.” Two years earlier, when she was an intern, a man came in with a sore just like this one. Like this woman, he had been on immune-suppressing medications. They tested him for everything, and it turned out that he had something fairly uncommon in Minnesota — he had been infected by a fungus called Histoplasma capsulatum, resulting in a condition called histoplasmosis. Bates thought it was likely that this woman had it as well.

A Dangerous Fungus

There are approximately 1.5 million different species of fungus on Earth, but only about 300 make people sick. Many live in soil and cause infection when the fungus is inhaled. Different fungi are common in different areas of the country. Histoplasmosis is one of the most common endemic fungal infections nationwide but is seen primarily in the Southern and central United States — around the Mississippi and Ohio River Valleys. The patient’s home was in a region where the fungus could be found. The organism is carried by infected bats or birds and deposited into the soil in their waste. When Bates went back to the patient’s room, she asked whether she’d had any exposure to soil or birds. Yes, she was an avid gardener — and she had many bird feeders.

The doctors ordered tests of blood and urine to look for the fungus. The dermatologist took biopsies of the red plaques on her hands. The tests confirmed infection the following day, and she was started on an intravenous antifungal treatment.

Most people who get histoplasmosis never know it. The infection is either asymptomatic or causes symptoms mild enough that patients don’t seek medical attention. Among those who have symptoms, most have a disease that is limited to the lungs, like bronchitis or pneumonia, that usually doesn’t need to be treated.

Not so for this patient. The test came back positive, and CT scans confirmed the presence of infection throughout her body, including in her chest and abdomen. The immune-suppressing medications she was taking for her arthritis had created a welcoming environment for the fungus. As she took more and stronger medications, her immune system was further weakened, and the fungal infection only got worse.


Slow Healing

Recovery for this patient was slow and difficult. Every day, she was given a bright yellow intravenous antifungal medication, which she called her Mountain Dew From Hell. Each infusion caused her heart to race and her blood pressure to spike. She had constant diarrhea. Despite treatment, the fungus ate through her gut, and she had to have a foot and a half of her small intestine removed in an emergency operation. In all, she spent four long weeks in the hospital and a few more in rehab back in Joplin. Even after all that, she had to take an antifungal medication every day for a year.

She is now nearly three years out from that long trip to Mayo. She will never be able to take any immune-suppressing medications again. Her arthritis bothers her a lot more now, but she says that taking extra-strength acetaminophen helps. Even though she’s off immune-suppressing medications, she doesn’t take any chances: Her bird feeders are gone. And every spring and summer, she has her six grandchildren do all her planting for her.