Even when a meal was labelled gluten-free or dairy-free that was not always the case, she said.
In one Tauranga restaurant there was just one gluten-free option on the menu, which when she ordered it, was served with (non gluten-free) croutons.
"[The staff] said 'just take them out'."
Miss Bassington said the effects of gluten on her body included severe stomach pain, peeling skin, extreme fatigue and weakened immune system. Her son got a bloated and uncomfortable stomach and a fever.
Lauren Cooke, who is also allergic to gluten, said it was now much easier to dine out than it was when she was diagnosed 35 years ago "and I'd be lucky to get a boiled egg".
Mrs Cooke, who owns the One Stop Gluten Free Shop, said many eateries now had a good understanding of food allergies.
"A lot of people complain about it, but they are running a business and they don't have to cater to everybody's whim."
She said it was more difficult for nut and dairy allergy sufferers than those who were gluten intolerant.
"When you get [allergies] that severe, it's probably a choice to stay home and cook your own meal.
"It's not fair on restaurants to cater for all the dietary needs."
Shari Hammond, whose son Zac suffers from multiple food allergies, agrees.
Zac, 14 months, is severely allergic to wheat, eggs, nuts and dairy, and is also allergic to sesame.
Mrs Hammond said if she visits a café with Zac, she straps him into a high chair and feeds him food brought from home.
But when he's old enough to eat out, she plans to follow a "common sense" approach.
"Like with a nut allergy, we wouldn't go to a Thai restaurant because the risk would be greater.
"It is a tricky one but ultimately it is my responsibility.
"You kind of have to trust people [that the food is safe] - if you are worried, you should bring your own food with you."
Luigi Barattieri, who owns Spuntino, Comida and Volare, said he tried to accommodate special food requests whenever possible.
But in special cases he asks customers to leave for their own safety.
"Very often people come in and say 'I'm allergic to mussels, if I eat anything that has been in contact with mussels, I will die'.
"I ask them to leave, because I don't have a separate chiller.
"They are insane going to a restaurant if they have such a high-risk allergy.
"We are in the food business, not health. As much as we are willing to help, there are limits."
Ian Walker, owner of Alimento, said there were increasing numbers of requests for special food.
The café had a range of gluten-free and dairy-free options and did their best where possible to cater to demands.
Hospitality New Zealand chief executive Bruce Robertson said most restaurants aimed to accommodate their customers.
"There's no doubt that more people are certainly looking for more information about the food they are eating related to allergies.
"[Restaurants] are not going to be able to assist everybody in every case, but the important thing is they should be able to give their customers accurate information."
Allergy New Zealand chief executive Penny Jorgensen said food allergies could limit participation in early childhood education and school activities.
"Eating out can be very challenging when you have to rely on others to prepare food that is safe for your child.
"Communities can help by learning about food allergy and how to help and support those dealing with it."
Food problems
Main foods causing food allergy in New Zealand: milk (dairy), eggs, peanuts, wheat, soy, tree-nuts, fish and shellfish.
Main foods causing allergies in New Zealand children: milk, eggs and peanuts.
Rates of food allergy globally have risen significantly in the past decade, and some, such as peanut, have risen dramatically. The reasons are not known.
Food allergy affects up to 10 per cent of infants in New Zealand.
Most children will outgrow their food allergies.
Allergy Awareness Week is May 13-19.
Source: Allergy New Zealand