Facial flushing can be a normal physiological reaction or a result of a disease state. For example, people who are easily shy may experience facial flushing in an emergency situation, while people who lack alcohol dehydrogenase and aldehyde dehydrogenase may experience significant facial flushing after drinking alcohol, which is caused by capillary dilation, and prolonged cold stimulation of the face. For example, eczema on the face, skin allergy to certain cosmetics or dust, and butterfly-shaped lesions caused by systemic lupus erythematosus.