An acquaintance who used to be an LC told me of her daughter who
was about 15 mo. old and almost weaned (1 nursing/day), had
severe eczema. Mother returned to exclusive BF to "clear the
decks" before food & environment challenges by
allergist/dermatologist. She reported that during 2 wks of
exclusive BF, the eczema cleared up beautifully. I'm not sure of
efficacy of exclusively BF 4 year old. I would think that mother
should go in direction of challenges, also, to get to bottom of
allergy source(s). Not exactly parallel, but hope it helps.
Regards, Judy Knopf