Dry Skin/Xerosis: Introduction
Dry skin, technically termed as xerosis cutis, is a common yet minor skin problem mostly prevalent in older adults. This is because moisture retention in the skin reduces as you age. Xerosis is a greek terminology, where Xero means dry, and Osis means medical condition.
Common causes of xerosis include:
- Showering with excessively hot water
- Cold and dry weather conditions
- Dehydration or poor water consumption
- Harsh soaps and detergents
- Prolonged sun exposure
Some medical conditions, like atopic dermatitis and malnutrition, are also significant contributors to dry skin.
How Does Genetics Contribute to Dry Skin?
FLG Gene and Dry Skin
The FLG encodes a protein, profilaggrin. It makes up most of the epidermal layers, which is the outermost layer of the skin. When the profilaggrin protein is cut, it forms the filaggrin protein, which is crucial for the structure of the epidermis. One profilaggrin molecule can make up to 10-12 copies of the filaggrin protein. Filaggrin also helps form other proteins that are involved in skin hydration.
Proper functioning of the FLG gene is necessary as the epidermis is the main skin barrier that helps minimize water loss from and entry of bacteria or other toxins into the body. It also helps maintain the acidic pH of the skin, which plays a main barrier role.
Certain variants in this gene result in the lower secretion of the protein or secretion of a dysfunctional protein. This interferes with the moisture lock-in, leading to dry skin.
rs61816761 and Dry Skin
rs61816761, more commonly known as R501X, is an SNP in the FLG gene. This mutation reduces the number of copies of the filaggrin protein. A allele of this SNP is associated with a higher risk of developing dry skin and ichthyosis.
There are also several other SNPs in the FLG gene associated with the risk of dry skin.
Non-genetic Factors That Influence The Risk of Dry Skin
Several medical conditions are known to cause dry skin. Some of them include:
- Diabetes: High blood glucose levels can contribute to dry, itchy skin.
- Atopic dermatitis: This condition causes dysfunction in the skin barrier. This results in more moisture loss, and therefore, dry skin.
- Hypothyroidism: Underactive thyroid gland results in decreased secretion of eccrine glands. They are the major sweat glands of the human body.
- Malnutrition: Certain nutrient deficiencies can result in dry and scaly skin.
- Lymphoma: Cytokines are compounds released in response to skin lymphoma. This can irritate the nerve endings and result in itchy and dry skin.
Other risk factors include:
- Season: Dry skin occurs more often during the cold seasons like winter and autumn.
- Age: People aged 40 years and older are more susceptible to dry skin.
- *Medications: Certain medications used to treat conditions like hypertension, acne, allergy, and cholesterol may lead to dry skin.
Effects Of Dry Skin
The hallmarks of dry skin are itchiness and loss of elasticity. Other effects of dry skin include:
- Pruritus: A sensation that urges you to scratch your skin
- The breaks in the skin due to scaliness can increase the risk of bacterial infections
- Inflammation of the dry skin can lead to red/pink patches
Recommendations to Avoid/Manage Dry Skin
- If you are already struggling with dry skin or are at an increased risk, it is important to stay away from products that contain
- Alcohol (with the exception of hand sanitizers)
- AHA - Alpha Hydroxy Acid
- Strong fragrance
-
Retinoids
-
Use skin moisturizers
Moisturizers contain three types of compounds: - Humectants: Help attract moisture
- petrolatum/mineral oil/silicone: Help retain moisture
-
Emollients (linoleic/linolenic acids): Fill the gap between the skin cells with moisture
Thicker and greasier moisturizing agents like petroleum jelly are more effective for preventing/managing dry skin. -
Hydration
Water helps replenish your skin cells from within. -
Use humidifiers
Dry air can suck the moisture right out of the skin. Humidifiers at the right setting (around 60%) help add moisture to the air. -
Skin-friendly fabrics
Bamboo, wool, and synthetic fabrics can irritate the skin. Wearing cotton/silk apparel under your woolen-wear can help avoid irritation. Ensure to use hypoallergenic laundry detergents.
Summary
- Dry skin, also called xerosis cutis, occurs when the skin loses its ability to absorb/retain moisture.
- It is commonly caused by dehydration, prolonged sun exposure, excessive showering with hot water, and cold and dry weather conditions.
- The ability to absorb and retain moisture is also influenced by the FLG gene. It codes for the filaggrin protein that helps minimize water loss from the skin.
- rs61816761 SNP is located on the FLG gene and is associated with a decreased number of filaggrin proteins. People with the A allele have an increased risk of developing dry skin and ichthyosis.
- Several medical conditions, like diabetes, hypothyroidism, malnutrition, and lymphoma, also cause dry skin. Certain medications used to treat conditions like acne can also dry up your skin.
- Using skin moisturizer and hydrating adequately are two effective ways to both prevent and manage dry skin.
