I also was exclusively breastfeeding my DS until he was 4.5 months but we recently switched to Nutramigen and his eczema cleared right up. We weren't really sure about exactly what was going on with him, he was EXTREMELY fussy, reflux, not eating, etc, etc, etc, and we've made a lot of changes (including cutting out dairy, wheat, and practically everything else from my diet) but have really noticed that since he's been on the hypoallergenic formula his eczema is gone! I know that's probably not the answer you were hoping for :-( But go ahead and try the exclusions from your diet and see if that makes a different. Every LO is different! Good luck!