By Dr Ananya Mandal, MD
There are treatments to alleviate the symptoms of eczema but there is no cure for the condition. Children with atopic eczema may often grow out of it as they age. Several new therapies are being tried in this condition that may severely affect the quality of life in an individual.
There are several immunomodulators or immunosuppressants like topical calcineurin inhibitors (e.g. pimecrolimus and tacrolimus) that are now being used in severe eczema. Many other agents that modulate the local immune system to treat eczema and its symptoms are being tried in various clinical trials.
As the condition is often related to family history and personal history of allergies, genes may be associated with eczema. Gene therapy of genetic engineering is a new avenue of research in eczema.
The body has its own protease inhibitors, such as, LEKTI, produced from the gene SPINK5 that protect it against damage from the enzymatic activity of allergens. Mutations in this gene are known to cause Netherton’s syndrome, which is a congenital erythroderma. These patients nearly always develop atopic disease, including hay fever, food allergy, urticaria and asthma. This could open new avenues for the understanding of eczema and its treatment.
Another gene has been identified that researchers believe to be the cause of inherited eczema and some related disorders. The gene produces the protein filaggrin, the lack of which causes dry skin and impaired skin barrier function.
Brain-derived neurotrophic factor (BDNF) and Substance P
These two chemical mediators in the body have recently been found to be associated with itching sensations associated with eczema. Studies in this direction have the potential to unfold a greater understanding of the pathology and newer development of medications to treat the condition.
Brain-derived neurotrophic factor, also known as BDNF, is a secreted protein that, in humans, is encoded by the BDNF gene. BDNF is a member of the "neurotrophin" family of growth factors, which are related to the canonical "Nerve Growth Factor", NGF. Neurotrophic factors are found in the brain and the periphery.
In the field of neuroscience, substance P (SP) is a neuropeptide: an undecapeptide that functions as a neurotransmitter and as a neuromodulator. It belongs to the tachykinin neuropeptide family. Substance P and its closely related neuropeptide neurokinin A (NKA) are produced from a polyprotein precursor after differential splicing of the preprotachykinin A gene.
In general, allergic conditions are on the rise. In England a study showed a 42% rise in diagnosis of the condition between 2001 and 2005, by which time it was estimated to affect 5.7 million adults and children. Whether the cause lies in genes or in the environmental factors is an avenue of research that is being explored by researchers.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)