The Covid-19 test proved dangerous for a US woman as a nasal swab test punctured her brain lining.

Doctors reported in a medical journal Thursday that the patient had an undiagnosed rare condition and the test may have been conducted improperly.

Jarrett Walsh, senior author of the paper that appeared in JAMA Otolaryngology-Head & Neck Surgery, told AFP that her case showed that healthcare experts should take care of resting protocols closely. He also said that people who had faced extensive sinus or skull base surgery should be tested orally.

Ear, nose and throat specialist Dennis Kraus of Lenox Hill Hospital in New York, said, “It underscores the necessity of adequate training of those performing the test and the need for vigilance after the test has been performed.”

Walsh told the international news agency that the woman had experienced nasal testing before elective hernia surgery. He said that he noticed a clear fluid emitting from one side of her nose.

She then contracted headache, vomiting, neck stiffness, and aversion to light. “She had been swabbed previously for another procedure, same side, no problems at all. She feels like maybe the second swab was not using the best technique, and that the entry was a little bit high.”

The woman had earlier been treated for intracranial hypertension. Thus, the pressure from the cerebrospinal fluid that protects and nourishes the brain was too high.

Doctors drained some of the fluid using a shunt and the condition resolved.

Walsh said he believed the symptoms she showed were because of irritation to the lining of the brain.

The patient could have developed serious life-threatening problems if she had not been treated on time.