Eczema and psoriasis are chronic inflammatory skin conditions, which appear to aggravate the conditions during the winter season, with a complex set of barrier dysregulation, activation of the immune system and hyperirritability. During cold weather, the level of humidity considerably reduces and the air is much drier than in other seasons. This dryness removes moisture in the skin, which makes the skin weak in terms of its natural lipid barrier. When this barrier is damaged the skin is unable to retain hydration and thus it becomes easier to react to irritants, allergens and microbes. This dryness causes an increased inflammatory response in people with eczema who already possess a genetically defective and dysfunctional skin barrier that results in severe episodes of itching, redness and scaling.The heating problem is also aggravated by indoor heating. Heat pumps and fans radically strike out the humidity within the indoor environment, which encourages as rapid trans epidermal passage of water. Repeated changes between the cold outside air and indoor air with temperatures below 20 degrees introduce further strains to the skin, which develops microscopic cracks that provoke inflammation. Eczema-prone skin can tend to find even minor irritants to be extremely severe due to the exposure of nerve endings and immune cells in these cracks. Psoriasis that is mediated by an overactive immune system that causes skin cells to regenerate faster is also sensitive to this type of change in the environment. Cold air dehydration and frequent skin stress may trigger the release of cytokines and immune systems that result in the thickening and expansion of psoriatic plaques.
Other habits that aggravate symptoms without being aware of it are affected by cold weather. Long, hot showers are a nice and soothing treatment but they leave the skin without the necessary oils and the lipid matrix that creates a strong barrier. Wool or synthetic thick winter clothes can lead to friction or entrap sweat that irritates sensitive skin and results in an inflammatory process. The human being also ends up drinking not much water during the winter resulting to internal dehydration which is manifested on the skin. Also, the nervous and immune system are closely connected; thus, seasonal stress can aggravate eczema and psoriasis.On the whole, the seasonal increase of eczemas and psoriasis is caused by a complex of factors including the lack of moisture in the environment, weakened skin barrier, changes in immune response, the lack of sunlight and habits in winter. The knowledge of such triggers will allow people to take preventive steps, adhere to the regular treatment and minimize the intensity of winter exacerbations.(Dr Pooja Chopra, Visiting Consultant -Dermatology, Aakash Healthcare)
