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About 50% of women declare they have sensitive skin. This skin sensitivity can create emotional turmoil when itching, burning and irritation are not even visible, or when irregular blemishes occur. Sensitive skin remains a largely unanswered problem since it does not correspond to a specific physiological pattern. It also presents the challenge of uneven skin appearance ranging from dryness to oiliness. The following highlights recent work related to sensitive skin and first impressions, interpretations in the brain, different types of sensitivity and more.
First Impressions
Judgments of character can be based on facial appearance which, in turn, guides personal interactions in terms of social engagement and/or avoidance. In fact, research has shown that people are particularly sensitive to skin blemishes as these may indicate poor health and the presence of an infectious disease. The negative effect of blemished skin also can create the impression that a person is immature and less trustworthy—versus the positive effects of smooth skin, which impart opposite assumptions of trustworthiness, competency, attractiveness and health.1
This legacy of skin sensitivity, in line with unpleasant sensory symptoms, motivates those with sensitive skin to take skin care seriously. Consider atopic dermatitis (AD) and allergic diseases, for example, which have increased dramatically during the past few decades. Scientific understandings of the risk factors for developing these conditions and effective preventive measures remain limited. In fact, there is evidence that skin barrier impairment and early-life atopic dermatitis could play a causal role in the development of skin sensitization. As such, skin care plays an important role, and the regular use of prophylactic emollients can significantly decrease the expression of AD while treatment continues.2
Subjective Sensations in the Brain
Skin sensitivity is also a subjective matter, as functional magnetic resonance imaging (fmRI) has shown. In one study, a brain scan was performed in attempt to objectify a neural basis for sensitive skin in subjects that had self-perceived sensitive and non-sensitive skin. The research showed that skin discomfort due to irritation by a lactic acid test caused increased activity in specific areas of the brain in all participants; specifically, the primary sensorimotor cortex contralateral to the application site; and the bilateral frontoparietal network including the parietal cortex, prefrontal areas around the superior frontal sulcus, and the supplementary motor area.
However, the activity was significantly larger in the sensitive skin group. Only in this group did the activity spread to other parts of the brain; specifically, the ipsilateral primary sensorimotor cortex and the bilateral peri-insular secondary somatosensory area. Therefore, self-perceived sensitive skin seems to show brain activation during irritation and a specific neurophysiological pattern.3
In dermatology, itch has been mapped in the brain since it is a common sensory experience associated with skin inflammation. The communitive signals between keratinocytes, the immune system and sensory nerves are responsible for the pathophysiology of itching. These signals begin in the skin, proceeding to the spinal cord and eventually ascending to the brain, where itch is processed.4
One study comparing electroencephalography (EEG) changes in the brain for burn patients with chronic itch showed decreased alpha activity in the occipital channels and decreased low beta activity in the frontal area under eyes-closed conditions. Itching in burns therefore seems to be associated with brain reorganizational changes at the cortical level, as characterized by the EEG pattern.5
Detecting Sensitivity Across Skin Types
The demand for cosmetics aimed at sensitive skin is increasing; however, no arbitrary methods have been set to detect skin sensitivity. An impaired barrier function is understood to play one role in sensitive skin. Heightened neural and vascular reactions are also implicated. . .
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References
- Jaeger, B., Wagemans, F. M. A., Evans, A. M. and van Beest, I. (2018, Jun). Effects of facial skin smoothness and blemishes on trait impressions. Perception 47(6) 608-625. Available at https://www.ncbi.nlm.nih.gov/pubmed/29580151.
- Lowe, A. J., et al. (2018, Feb). The skin as a target for prevention of the atopic march. Ann Allergy Asthma Immunol 120(2) 145-151. Available at https://www.ncbi.nlm.nih.gov/pubmed/29413338.
- Querleux, B., et al. (2008, Nov). Neural basis of sensitive skin: an fMRI study. Skin Res Technol 14(4) 454-461. Available at https://www.ncbi.nlm.nih.gov/pubmed/18937781.
- Yosipovitch, G., Rosen, J. D. and Hashimoto, T. (2018, Nov). Itch: From mechanism to (novel) therapeutic approaches. J Allergy Clin Immunol 142(5) 1375-1390. Available at https://www.ncbi.nlm.nih.gov/pubmed/30409247.
- Miraval, F. K., et al. (2017, Aug). A preliminary study on qEEG in burn patients with chronic pruritus. Ann Rehabil Med 41(4) 693-700. Available at https://www.ncbi.nlm.nih.gov/pubmed/28971055.
