1 in 250 people has dry “fish scale” skin. It is caused by a lack of filaggrin – a protein that occurs naturally in the skin and plays a vital role in maintaining a healthy skin.
Dry and scaly skin that may resemble fish scales. Those are the symptoms of a skin disorder called “fish scale” skin or Ichthyosis vulgaris. The name ichthyosis comes from Greek and means fish. Vulgaris means common.1
Who might get dry “fish scale” skin?
Approximately 1 in every 250 people has ”fish scale” skin, often on the arms and legs. It is most often heritable, caused by a mutation in the gene responsible for producing filaggrin – a protein that occurs naturally in the skin and plays a vital role in maintaining a healthy skin.1
What causes dry “fish scale” skin?
“Fish scale” skin occurs when a gene mutation results in a defective production of filaggrin, leading to filaggrin deficiency in the skin.1
Filaggrin helps maintain a normal pH balance in the skin, which is essential to maintaining an effective skin barrier. The skin barrier is our body’s outermost layer of protection against the surroundings and prevents water from evaporating from the body.1 Filaggrin is also vital for the skin’s ability to remain hydrated because it breaks down into water-binding amino acids or “natural moisturizing factors” (NMFs) that help keep the skin adequately hydrated.
Filaggrin deficiency leads to reduced skin hydration, resulting in dry and scaly skin where the dead skin cells accumulate in thick, dry scales on the skin surface.
If you have dry “fish scale” skin due to a lack of filaggrin, your skin has a less robust skin barrier and needs help to stay properly hydrated. The regular application of ordinary moisturizing creams will have little effect because the lack of filaggrin makes it difficult for the skin to bind water.
The dry, scaly skin can be hydrated with creams that increase the skin’s natural water-binding capacity by adding amino acids that are a natural part of the skin’s properly functioning moisturizing factor (NMF) to the skin.
DermNet NZ: Topics: Ichthyosis vulgaris. Available at https://dermnetnz.org/topics/ichthyosis-vulgaris (Last visited 22 April 2022)