If you scratch an area of your skin, levels of two blood chemicals rise accordingly, say scientists from the Chinese University of Hong Kong. This new discovery, they say, could lead the way to devising new treatments for eczema and itching.
You can read about this in the British Journal of Dermatology.
The researchers had 28 children wear a device they called a DigiTrac monitor on their dominant wrist while sleeping. The device monitors how much you scratch during your sleep – it was programmed to record motion from 10pm until 8am the following morning. All the children in this study suffered from Atopic Dermititis (a type of eczema). Their disease severity was assessed with the SCORAD Index (SCORing Atopic Dermatitis), as was their quality of life with the Children’s Dermatology Life Quality Index (CDLQI).
The scientists found that the levels of two specific blood chemicals – brain-derived neurotrophic factor (BDNF) and Substance P – went up according to how much a child scratched.
This study could, say some dermatologists, help us find out what causes eczema. Although there are treatments that help reduce the symptoms, not much is known about what causes the itching.
“As far as we are aware, this is the first report to demonstrate that BDNF and substance P are significantly linked to disease activity, quality of life, as well as the levels of scratching as recorded by the wrist monitor,” said team member Kam-lun Ellis Hon.
In the report, the writers conclude “The strong correlations with nocturnal wrist movements suggest that they (BDNF and substance P) may be the pathogenic factors of the annoying symptoms of scratching.”
What is Eczema?
Eczema, or dermatitis as it is sometimes called, is a group of skin conditions which can affect all age groups. In the United Kingdom, up to one fifth of all children of school age have eczema, along with about one in twelve of the adult population.
The severity of the disease can vary. In mild forms the skin is dry, hot and itchy, whilst in more severe forms the skin can become broken, raw and bleeding.
Although it can sometimes look unpleasant, eczema is not contagious. With treatment the inflammation of eczema can be reduced, though the skin will always be sensitive to flare-ups and need extra care.
What Causes Eczema?
The causes of eczema are many and varied, and depend on the particular type of eczema that a person has.
Atopic eczema is thought to be a hereditary condition, being genetically linked. It is proposed that people with atopic eczema are sensitive to allergens in the environment which are harmless to others.
In atopy there is an excessive reaction by the immune system producing inflamed, irritated and sore skin.
Associated atopic conditions include asthma and hayfever.
Other types of eczema are caused by irritants such as chemicals and detergents, allergens such as nickel, and yeast growths.
In later years eczema can be caused by a blood circulatory problems in the legs.
The root cause of of eczema remains to be explained, though links with environmental factors and stress are being explored. For more information, go to www.eczema.org
“Pathophysiology of nocturnal scratching in childhood atopic dermatitis: the role of brain-derived neurotrophic factor and substance P”
K-L.E. Hon, M-C.A. Lam, K-Y. Wong, T-F. Leung, P-C. Ng
British Journal of Dermatology doi:10.1111/j.1365-2133.2007.08149.x
Click here to view abstract online
Written by: Christian Nordqvist