Patches of severely dry and scaly skin. Dead cells of the cutaneous surface accumulate in polygon-shaped scales in a similar pattern to a fish’s scales.
There are more than 20 different types of ichthyosis but the most common type by far is ichthyosis vulgaris. It is also the mildest form.
The skin may seem normal at birth, but then gradually becomes dry, rough and scaly in the first year of life. The face and elbow and knee flexures are not normally affected. The limbs may develop fine light-grey scales.
The skin on the palms of the hands and soles of the feet may be thickened and the child often also has eczema.
Symptoms are often worse in the cold and improve in warm conditions.
Treatment aims to reduce dryness, splitting and thickening of the skin. This is through the use of emollients and exfoliation.
References
https://www.aad.org/public/diseases/a-z/ichthyosis-vulgaris-overview