See a dermatologist. No diet works for eczema. Allergy tests should not be done. "chinese" medicine will not help ; its safety must always be questioned. Long baths followed immediatly by a topical for dry skin are basic. I like creams with ceremides. A dermatologist may teach you to use prescription ointment. No antihistamine will help. No cure but much can be done. With time it is likely to become less severe, espec.
Change diet. Eliminate dairy and gluten from the diet. Use perfume free lotions and use them 2-3 x a day. Do not use harsh soaps and do not bathe too frequently...After baths pat dry and lotion up immediately as the damp skin will absorb better. Chinese medicine can also be helpful in treating. Eczema is an allergic condition and foods affect it.