Facial erythema (the "red face") is a straightforward clinical finding; however, a red face does not represent a single cutaneous entity. In other words, in clinical practice, dermatologists do not encounter only one type of facial erythema but rather a number of different shades of red. Diagnosis is based on different data: date and mode of appearance, characteristics of the erythema, functional signs, and associated systemic manifestations. A case of red face can have an infectious origin, caused by vascular, congenital, or acquired lesions, or be caused by photodermatosis, or be the main location of inflammatory dermatosis or collagenosis, but depending on the clinical context, many other diagnoses can be suggested. This lecture presents the clinical spectrum of facial erythemas and addresses the question of what lies beneath a red face by discussing the key pathophysiologic characteristics focusing on skin barrier.