| Allergic reactions to medications or foods can cause acute hives or angioedema. |
| Two very severe forms of allergic reaction — angioedema and Stevens-Johnson syndrome — cause swelling of the mucus membranes and lips. |
| Body as a whole: allergic reactions including urticaria, ecchymosis, angioedema. |
| Foods high in histamine, such as fermented foods, may exacerbate urticaria and angioedema in these individuals. |
| Other substances that can cause hives and angioedema include pollen, animal dander, latex and substances injected into your skin from insect stings. |
| Hereditary angioedema usually first appears in late adolescence or early adulthood. |
