Parents have asked me if a diagnosis of a food allergy can be made by placing the food on the skin.
The answer is, not always.
Why is that?
Not all concentrations of the allergen can lead to a reaction.
𝐂𝐨𝐧𝐭𝐚𝐜𝐭 𝐃𝐞𝐫𝐦𝐚𝐭𝐢𝐭𝐢𝐬 happens when a substance gets in contact with the skin, causing a localised reaction.
It can be either 𝘪𝘳𝘳𝘪𝘵𝘢𝘯𝘵 (80% of reactions) or 𝘢𝘭𝘭𝘦𝘳𝘨𝘪𝘤 (20% of reactions), leading to different reactions.
It affects people that deal with the substances frequently, though it can happen to anyone.
Treatment starts with avoidance of contact with the substance causing the reaction.
Following this, the creams used are very similar to the ones used in eczema.
It is not frequent the need for oral or intravenous medication.
How to make a diagnosis?
There is also a difference in signs.
Nickel can give irritant and allergic contact dermatitis.
Recent research showed an association between the decrease or absence of anti-inflammatory bacteria and the increase in some 𝐩𝐬𝐲𝐜𝐡𝐢𝐚𝐭𝐫𝐢𝐜 𝐝𝐢𝐬𝐨𝐫𝐝𝐞𝐫𝐬.
This was associated with the increase in pro-inflammatory bacteria.
And what are the bacterias involved?
They believe this relates to the low production of 𝐁𝐮𝐭𝐲𝐫𝐚𝐭𝐞 from the absent bacteria, as this leads to an anti-inflammatory effect, mainly in the bowel.
But please don’t go and start eating it by the bucket load, as this is not the best way to increase 𝐁𝐮𝐭𝐲𝐫𝐚𝐭𝐞 in your system!
Take this research with caution, as the study did not take into account individual variables.
And despite the finding of this exciting relation, some studies directly aimed at this association have not yet proven the link.
What is important is that there starts to exist some evidence that might lead to a better understanding of the connection between gut health and mental health.
This study was done at 𝐊𝐢𝐧𝐠’𝐬 𝐂𝐨𝐥𝐥𝐞𝐠𝐞 𝐋𝐨𝐧𝐝𝐨𝐧, in association with the 𝐌𝐚𝐮𝐝𝐬𝐥𝐞𝐲 𝐇𝐨𝐬𝐩𝐢𝐭𝐚𝐥.
Dr Costa is a Consultant Paediatrician and fellow of the Royal College of Paediatrics and Child Health.