(CBS NEWS) -- Tamela Wilson worked at a state park for more than 10 years, so she wasn't fazed when she spotted ticks on her skin. She simply picked them off without giving it a second thought.
The 58-year-old didn't worry about contracting a tick-borne illness — but that's exactly what happened.
Three days after Wilson, the assistant superintendent at Meramec State Park in Missouri, plucked two ticks off her body in late May, her health started to deteriorate.
She visited her primary care doctor to share her concerns and was diagnosed with a urinary tract infection, given antibiotics and sent on her way.
A day later, things took a turn for the worse.
"She literally couldn't even pick up her phone. She had no strength," Wilson's daughter, Amie May, told CBS News. "My sister had been calling her and couldn't get a hold of her. My mom said the phone was right there ringing, but she could not pick it up to answer it."
Wilson then returned to her doctor and described having severe headaches, pain and a light red rash. After undergoing several tests, she was told she had a low white blood cell count and was admitted to Barnes-Jewish Hospital in St. Louis.
"They did a couple skin biopsies, but they came back fine," May said. "They did other testing for tick-borne disease, but those were also negative."
For days, Wilson and her children prayed for answers.
"They told us, you know, basically, they were hoping it would leave her system," May said. "They would continue treating her symptoms and hope everything would go away on its own."
But Wilson's health continued to decline. She developed hemophagocytic lymphohistiocytosis (HLH), a condition affecting her immune cells. The rash spread to other parts of her body, even her mouth.
"I'm a nurse and I've never seen anything like I'd seen my mother's mouth," May said. "It got so bad toward the end she couldn't talk, couldn't drink, couldn't eat — nothing."