A teen has red, splotchy-looking dry rash. Are there certain foods to eat or restrict?

This patient has a rare skin disease. The patient with this is only 16 years old. She has it only on her hands. It is red, splotchy-looking dry rash. Her parents requested that I try to find out if there is anything out there regarding certain foods to eat or restrict. They know toxic levels of Vitamin A in supplement form are the most effective treatment, but there are side effects to doing that, even short-term. I did a Med-line search and most titles are related to Vitamin A supplements. Thank you for any help you can send my way.

 Is the patient seeing a dermatologist and what did he/she recommend? Have you checked the Merck Manual or the American Academy of Dermatology? Have you done an online PubMed search for the disease?