Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Daily oral medication is not indicated/necessary for the management of eczema. This medication has a sedating effect and it is also sometimes used for people with psychiatric history. It is also used for allergies but eczema is best managed by using lotions applied to the skin. If the skin is dry then the rashes tend to occur. Therefore, an intense emollient (for dry skin) is needed. Urea and glycerine are commonly used. A mild steroid cream can be applied to the skin in the affected area, when an outbreak occurs, a stronger cream can be used. If you are using the promethazine because you suspect that he has an allergy, it would be best to determine what he is allergic to and reduce his exposure to this agent. At 8 months, his diet should still be relatively simple and you would have done the 3 days for each food introduced (every time a new food is used, it is used for 3 days to see if allergic). Monitor his diet and look at any other soaps, creams, detergents. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Michelle Gibson James