Dr Mich Lajeunesse is a Consultant in Paediatric Allergy and Immunology at University Hospital Southampton (UHS) and part of the Research Leaders Programme (RLP).

He aims to improve the diagnosis and treatment of milk allergy in babies and children.

Focussing on his own research

Mich first joined UHS in 1996 and returned as a consultant in 2008. He has been research active throughout his career.

Recently, this has been mainly involved commercial research, where he has been extremely successful, with a turnover of over £1 million in the last five years.

“One of these studies has been the Natasha Clinical Trial,” Mich explains. “This has been quite high profile nationally, and has captured the imagination of parents and professionals.”

However, while he has led his own research projects, he has found it difficult to maintain a steady stream of research grant income. He says this is due to a lack of time for grant applications.

“You can’t do everything,” he says. “You can’t be a full-time NHS consultant and write grants - there’s just not enough hours in the day.”

With his new RLP award, he now hopes to be able to focus more on his own research. He also intends to bring others with him, particularly dietitians and allied health professionals.

Undetectable allergies

The standard tests to diagnose milk allergy are a blood test and ‘skin prick’ test, where a drop of allergen is put on the skin and the skin pricked. A small, red, itchy lump indicates a positive result.

Both tests rely on the allergic reaction being mediated by immunoglobulin E (IgE). This is an antibody that plays a key role in some allergic reactions to milk. However, it is also possible to have a non-IgE mediated allergic reaction, which these tests cannot detect.

“When they are really little, a lot of children with milk allergy don’t have positive allergy tests,” Mich explains. “Some of them never develop positive allergy tests, but they’ve still quite clearly got allergic symptoms to milk. It’s a bit of a conundrum really.”

Unlike IgE allergies, which give immediate symptoms such as hives or anaphylaxis, non-IgE allergies tend to have long-term effects. These include eczema and chronic gut symptoms, including acid reflux, vomiting and diarrhoea.

“The symptoms of milk allergy in babies can be really pervasive. The child can be really unhappy, won’t feed, won’t sleep, and that’s tough,” says Mich. “If you’re having that day on day, then it’s really wearing, and it not only affects the child, but impacts the whole family.”

Improving the patient journey

Without a positive milk allergy test result, parents can struggle to get the care they need for their child. This can lead to unnecessary suffering, affecting the whole family’s quality of life.

Mich not only knows about this through his clinical work, but also through his own personal experience, as his own children had milk allergies that didn’t show up on the tests.

During his RLP award, Mich plans to explore how to improve patients’ journey through the healthcare system. He’s doing this in partnership with parents of children with milk allergies.

This process is known as patient and public involvement and engagement (PPIE). So far, he’s had two meetings with these parents. 

They are helping to make sure his research is acceptable to parents like themselves, who are the people who will be asked if they wish to take part.

“We have a group of very engaged parents, mostly mums, who’ve had babies with milk allergy. They realise what a struggle it is, so they’re really keen to improve the lives of other families in the same position.”

Developing a new allergy test

Mich is using his RLP award to better understand the processes involved in non-IgE milk allergy, and to develop a new diagnostic test for babies who have it.

This is based on previous research he did on T cells with a team in California. T cells are part of the immune system. They help recognise and attack allergens such as milk proteins.

This research was funded by the National Institutes of Health, as part of a wider $2m project. It looked at whether there was a signal in the T cells of older children and young adults that could be used to predict if they would grow out of their milk allergy.

Mich now plans to use the same approach to develop a blood test for non-IgE milk allergy in babies. This will involve identifying a non-IgE mediated signal that indicates a milk allergy.

This will require using much smaller blood samples – a tenth of the size used for adults. He therefore aims to see if it would be physically possible to detect T cells in such small samples.

“I’m now going to apply the work we’ve done with older children to babies, to see whether we can get a similar sort of signal,” says Mich.

“If we can get a signal from these T cells in their blood tests, then potentially we could develop a test for milk allergy where one doesn’t currently exist.”