FORT LAUDERDALE, Fla. -

An estimated 50 million Americans suffer from all types of allergies.

"Trees, grass, bark, dust, dust mites, cockroaches for some reason, dogs, cats," said Rob Marsh. "Everything."

Marsh said allergies make working as a carpenter very difficult.

"It's one of those things you can't avoid, especially in my line of work with the dust. I'm at the shop, I'm cutting wood. I'm actually allergic to wood so there's really no way to get around that," he said.

Marsh tried allergy shots years ago.

"You usually have to go to the doctor at least once a week, get your shot, wait in the doctor's office and make sure you don't have a reaction to that shot and it's quite inconvenient," said Dr. Richard Callari.

While searching for something better, Callari found allergy drops.

"We test to see what you're allergic to and then we make a custom mix of the what you're allergic to for every patient individually," he said.

"You do it yourself. You take it in the morning or the night or whenever you want -- whenever it's convenient for you," said Marsh. "You don't have to go somewhere and wait in the waiting room, wait for the shot. It's an hour and a half process. You do it at the house, it takes two seconds, so it's pretty simple."

Marsh said the drops helped him enjoy life's little pleasures.

"I was always stuffed up and I thought that's just the way life was and then I'm taking the drops now and I can taste my dinner and I can smell the beach and it's nice. I love it," he said.

While are fewer reported adverse side effects with allergy drops versus shots, they do take as long to be optimally effective -- up to three years -- and the cost, usually about $125 a month, isn't covered by insurance.

The annual cost of allergies in the U.S. is estimated to be more than $14 billion, which includes doctor visits, medications, and loss of productivity through missed work and school.