The effects of redface are identical to those of sight rot (see "Diseases" in chapter 8 of the Dungeon Master's Guide), but it's caused by pollutants in the air rather than contaminated drinking water, making it difficult to avoid.
Redface
DiseaseGoSp. 1682014
Raw data
{
"name": "Redface",
"page": 168,
"__prop": "disease",
"source": "GoS",
"entries": [
"The effects of redface are identical to those of {@disease sight rot} (see \"{@book Diseases|DMG|8|Diseases}\" in chapter 8 of the {@book Dungeon Master's Guide|DMG}), but it's caused by pollutants in the air rather than contaminated drinking water, making it difficult to avoid."
]
}