​Dermatology - X-linked Ichthyosis

​Dermatology - X-linked Ichthyosis
X-linked ichthyosis is a genetic disorder that is inherited through the X chromosome and is characterized by a deficit in steroid sulfatase. This condition primarily affects boys and leads to the buildup of keratin on the skin, known as retention hyperkeratosis, while the growth of the outer layer of the skin remains normal.
The onset occurs shortly after birth.

20% of individuals with the illness experience cryptoorchidism. Age does not contribute to improvement, and the condition typically deteriorates in temperate areas, particularly during the winter season.

The presence of extensive, firmly attached scales that have a brown or soiled appearance is particularly prominent on the back of the neck, the outer surfaces of the arms, the inner elbows, the back of the knees, and the trunk. Palm, sole, and face are not affected. Comma-shaped stromal corneal opacities can be found in 50% of adult males' eyes. These opacities are asymptomatic and can also be present in certain female carriers.


The diagnosis is made based on the family history and clinical observations. Prenatal diagnosis can be achieved using amniocentesis and chorionic villus sample. The differential diagnosis encompasses all types of ichthyosis, including syndromic ichthyoses.


The most effective way to manage this is by hydrating the affected area through immersion in a bath, followed by the application of petrolatum. Urea-based creams effectively retain moisture in the outermost layer of the skin, known as the stratum corneum. A solution containing 44-60% propylene glycol in water, along with 6% salicylic acid in propylene glycol and alcohol, when applied under a plastic covering, will effectively hydrate the skin. However, caution should be exercised to avoid hypersalicylism.
Hydroxy acids, specifically lactic acid and glycolic acid, are able to regulate the process of scaling. Preparations that contain urea in concentrations ranging from 2% to 10% have proven to be helpful. Retinoids, namely isotretinoin and acitretin, have high efficacy; nonetheless, diligent monitoring for potential harm is necessary. Intermittent therapy may be necessary only for severe instances.