The mold that pervaded New Orleans after Hurricane Katrina didn’t increase overall allergies to mold, a new study finds.

About one in 10 patients tested for mold sensitivity was allergic to mold, regardless of whether they were living in a damp or moldy house, said epidemiologist Felicia Rabito of the Tulane School of Public Health and Tropical Medicine.

That’s also the same rate found nationwide, Rabito said Thursday.

The study began four months after Katrina hit on Aug. 29, 2005, and less than two months after the last floodwaters were pumped out of New Orleans on Oct. 12, 2005. Doctors and returning residents worried about widespread mold allergies.

It covered patients who got a skin test for mold sensitivity between December 2005 and December 2008 at Ochsner Health System’s allergy, asthma and immunology clinic. About one-third of the 529 patients reported their homes were damp or moldy.

“This study and others we’ve conducted seem to indicate that there was no lasting effect,” said Rabito, lead author of the study published online by the Journal of Allergy.

Dr. Judd Shellito, chief of pulmonary medicine at LSU’s medical school, said the study reinforces the impression he’s had from his own practice since Katrina.

“I think it should be reassuring to the general public,” said Shellito, who did not participate in the study.

Rabito emphasized that researchers looked only at people who had health insurance. “People at highest risk for mold sensitivity may be those with limited incomes who could not afford to stay out of their houses for long periods of time, who did significant amounts of renovation work, and who may not have access to health care,” she wrote. “Studies targeting this subpopulation are needed.”

It also didn’t look at people who developed respiratory illnesses — not allergies — that might have been caused by mold or pollution. Patients included people from age 1 to 93, with an average age of 41.

A study released in August found that children with moderate to severe asthma who were tested after Katrina were much more likely than those in other cities to be allergic to mold.

Many of the children in that study were poor and lived in damp, moldy houses, said Dr. Maureen Lichtveld, also of the Tulane School of Public Health and Tropical Medicine, who worked on that study.

“They didn’t have the luxury to move,” she said.