It's not very common and it's not very contagious — but for those who contract shingles, it's very painful.
On April 22, an Edmonton woman was taken off her flight home from Halifax due to a shingles rash on her face that flight crews thought may have been contagious.
An Edmonton microbiologist said though the woman's shingles weren't contagious, he doesn't blame the airline for reacting the way it did.
Shingles contagious through open wounds
Tetro, author of The Germ Files, said shingles is caused by the chickenpox virus — but the chickenpox virus is much more contagious than shingles.
He said a person with chickenpox can spread the virus to 10 people quite easily.
"With shingles, it doesn't do that — it stays in the nerves and starts to create a rash that's incredibly painful," Jason Tetro told CBC's Radio Active. "Sometimes you'll get blisters, which are just evilly painful for about three to five weeks."
Shingles can be contagious but only if the blisters are open wounds, Tetro said.
The disease affects one of every 200 people, he said.
A person can't have shingles unless they've had chickenpox. Once successfully fought off, the varicella-zoster virus can lay dormant in a person for many years and never reactivate.
When the virus does activate again, that's when a person gets shingles.
"It's staying, for the most part, underneath the skin, therefore it's very difficult for it to be aerosolized so that you can pick it up in your nose," Tetro said.
'Post-Ebola scare world'
The Edmonton woman on the flight from Halifax wasn't contagious, and Tetro said the airline refusing to let her fly home was an overreaction.
But he said with other recent scares in airplane cabins, it made sense why the airline was nervous.
"It's an overreaction, but we do live in a post-Ebola scare world," he said. "I don't think it's something that airlines can be condemned for."
The event came a month after Air Canada was criticized for letting a passenger with measles on a flight from Zurich to Toronto.
"[They were] taken to the dungeons over the fact that they let measles onboard, so it's a tough situation," Tetro said.
He said vaccinations against chickenpox and shingles will prevent events like this from happening in the future. But he said if a similar situation arises, airlines have options.
"If you do happen to see someone with a rash or blisters like that, don't panic," he said. "If you do have a concern, all airports have a health and safety and emergency medicine place."