Epilepsy variant 癎

A variant of 癇 used in medical terms for epilepsy and convulsions.

The oldest documented lexical trail for this character family starts with 癇 in the Shuowen Jiezi, a dictionary from the Han dynasty, which defines it as an illness. Its left side, 疒, marks illness; 閒 supplies the sound. 癎 is the variant written with 間 in that position. Later medical terms use this character family for seizure disorders.

How does 癎 differ across Chinese, Japanese, and Korean?

Chinese keeps the medical sense; Japanese uses 癇 in an anger-related compound.

In Chinese, 癎 is a variant of 癇; simplified Chinese uses 痫 for the medical term. 癲癎 and 癲癇 are spellings for epilepsy. Korean dictionaries record 癎疾 as the former Hanja, or Chinese-character, spelling of 간질, the Korean word for epilepsy. Japanese uses 癇 in 癇癪 for a fit of temper; that anger sense belongs to the compound, not to a lone 癎.

Older epilepsy terms can link seizures with madness. In 2010, Hong Kong's Hospital Authority changed its clinical term from 癲癇/癲癎 to 腦癇症, moving away from that older association.

Should I send 癎 by itself?

Usually no; alone, its language and use are unclear.

It reads as a medical character, but without the surrounding word or a clear source, the intended meaning is hard to identify. Keep it when quoting a record or discussing medical terminology; use the full Japanese word 癇癪 for a temper tantrum.