Edema and Giant hives

Edema noun - Swelling from excessive accumulation of watery fluid in cells, tissues, or serous cavities.

Giant hives and edema are semantically related. In some cases you can replace phrase "Giant hives" with "Edema", this terms are similar.

Giant hives noun - Recurrent large circumscribed areas of subcutaneous edema; onset is sudden and it disappears within 24 hours; seen mainly in young women, often as an allergic reaction to food or drugs.

Edema and giant hives are semantically related. You can use "Edema" instead a noun phrase "Giant hives".