Seborrheic dermatitis (SD) is a common inflammatory skin condition primarily affecting the scalp, face and chest. It appears as red, flaky, greasy patches or plaques and can cause itching and discomfort. It is a non-contagious condition varying in severity, from mild dandruff to persistent inflamed lesions. What we know: SD is linked to three main factors: increased sebum (oil) production, colonization by Malassezia  yeast, and an abnormal immune response. Genetics, skin barr