Royce Thomson camped for a night at the spot recently and woke up to discover he had been bitten on his arms, by what he believed were mosquitoes.
He ended up seeking treatment at Dunedin Hospital for a secondary infection which needed intravenous antibiotics.
"I was seriously ill. My hand blew up."
Mr Thomson was concerned that if families with small children visited the picnic spot someone else could also get seriously ill.
Dunedin Hospital emergency department consultant John Chambers said mosquitoes in New Zealand did not carry infectious diseases like other countries and it was not unusual to get a secondary infection when bitten multiple times.
The hospital had not had any other similar cases.
Otago and Southland Medical Officer of Health Dr Marion Poore said a health protection officer had visited the site and discovered a lot of standing water in old tyres and deep water ruts.
There was certainly the habitat for mosquitoes to breed but while there was a lot of larvae present in the tyres, the officer did not think it was mosquito larvae, she said.
There was also a lot of larvae in the water ruts.
"Clearly, there is a problem with standing water there."
She advised visitors to the area to wear insect repellant and cover up.
No other complaints about mosquitoes in that area or any other had been made, she said.
"We're taking a watching brief."
