The disease is most common in young children and appears to be hitting Tauranga preschoolers.
Toi Te Ora Public Health Service medical officer of health Dr Neil de Wet said there had been an increase of hand, foot and mouth cases across New Zealand, including Tauranga.
"It's been going on for several weeks. It's a very common childhood viral illness, most people would have been exposed to it by the time they reach adulthood."
Dr de Wet said the strain of virus doctors were seeing seemed to cause a slightly wider spread of rash.
"Although it is a mild illness, this strain appears to be affecting people more strongly."
Tauranga baby Blake McCormick was unlucky enough to contract hand, foot and mouth just days before his first birthday. Mum, Cath Darragh, said Blake had a high temperature overnight so she took him to the doctor the next day.
"By then he had a rash on his face and had big blisters between his toes, although they didn't seem to worry him. He also had a throat infection which could likely have been blisters in his throat. When the blisters came, he was back to himself except he was off his food for four days."
Miss Darragh said other children in her SPACE playgroup had also come down with the illness. Two parents of children had also been affected.
Bright Beginnings childcare centre manager Katie McQuilter said she had seen an outbreak but it seemed to have been and gone.
"It seemed to be a couple of weeks ago and it was definitely a harder strain to get rid of. We had quite a few that had it but were okay to come in. It must have been quite contagious because it seemed to be everywhere. I have friends in other centres that were talking about it."
Beginnings and Beyond Quality Preschool head teacher Donna Emery said they'd had children who had contracted the illness. She had also heard about school-aged students who were coming down with the disease.