Vitamin A acid is used for the systemic treatment. This compound is a proven keratolytic agent. It is used only in severe cases because of the dangers of Vitamin A toxicity from the high doses necessary to get therapeutic results. For topical treatment of mild cases of ichthyosis a keratolytic agent is used along with a hydrating agent. Keratolytic agents are chemicals that will induce the scaling of the skin.
Some keratolytic agents are salicylic acid, urea, and propylene glycol.
Salicylic acid is not a good choice for long term therapy because there is a risk of salicylic acid toxicity. Salicylic acid can be absorbed through the skin and accumulate with long term use. Symptoms of tinnitus, nausea, dyspnea and hallucination can manifest. Urea and propylene glycol are available in many skin care products. Vitamin A acid has also been used topically as a keratolytic agent.