What is ‘ferritin face’ and why is this health scare trending on social media?

Ferritin is a protein that stores iron and its level is used to assess the body’s iron stores. Low ferritin can occur before iron-deficiency anaemia develops. However, it does not produce a distinct facial appearance. Terms such as ‘iron-deficiency face’ and ‘ferritin face’ circulating on social media are not recognised medical diagnoses