An illness spreading in California children has doctors stumped, but the polio-like symptoms are spreading fear in parents around the state.

The amount of cases has jumped up to about 25 since 2012, when a 2-year old was first diagnosed. At first, doctors thought she had a bad asthma attack and hospitalized her for respiratory problems, but then her mother noticed that she wasn’t able to use one of her arms correctly.

“He told us right away that the prognosis was really poor and that she’s not going to get better,” Sofia Jarvis’ mother, Jessica Tomei, said of the doctor’s diagnosis after more testing was done. The little girl survived the mysterious illness but is now paralyzed in her left arm and suffers weakness in her legs and lungs.

“What’s we’re seeing now is bad. The best-case scenario is complete loss of one limb, the worst is all four limbs, with respiratory insufficiency, as well. It’s like the old polio,” said Keith Van Haren, a pediatric neurologist in Palo Alto, Calif. “This is really very rare. But we are asking any families who notice a sudden onset of weakness to see their doctors immediately. Their doctors should contact the California Department of Public Health.”

The CDPH is working with the Center for Disease Control in Atlanta to figure out if similar cases have been reported in any other states; so far, there have been none. But that may be because other doctors don’t know what they’re seeing.

“My goal is to get the word out to other neurologists, to make them aware of this,” Van Haren said.

Image via Thinkstock