A severe version of this disease can exist in newborns;
It’s called the Harlequin Ichthyosis; A rare skin disorder present at birth, characterized by massive, hard, armor-like scales of skin separated by deep red cracks.
The child must inherit a mutated gene from both carrier parents in order to get this condition.
Treatment includes frequent warm baths, gentle removal of loose scales, and constant application of moisturizers.
Pretty sure no icthyosis (which is a condition of simply having horribly dry skin) is any kind of psoriasis.