Urticaria :: Hives, urticarea, nettle rash – Misconception
Angioedema is a related condition where similar types of swelling occur in a lower layer of the skin, mouth or throat. It is not identical to urticaria. They may, however, occur together.
The rash derived from poison-ivy is commonly mistaken for urticaria. Poison-ivy is caused by urushiol toxin. This resin can be spread by contact, but it is easily washed off.