1.
hives; urticaria; nettle rash
A skin condition characterized by raised, itchy welts that appear suddenly. Caused by allergic reactions, stress, or other triggers.
Usage
蕁麻疹 is the standard medical and everyday term for hives. The kanji are difficult and rarely written; the word is most often written in hiragana (じんましん) or katakana (ジンマシン) in everyday contexts.
Common patterns
The most common verb pattern is 蕁麻疹が出る (hives appear/break out). Note that Japanese uses 出る (to come out) rather than a verb meaning "to get."