Association Between Diet and Seborrheic Dermatitis: A Case-Control Study

Introduction Seborrheic dermatitis (SD) is a chronic, inflammatory papulosquamous skin disease. The symptoms and signs of SD are typically managed by topical ketoconazole and topical corticosteroids. However, they don't provide a cure for SD, which explains the disease's chronic nature. With this study, we aimed to identify specific dietary modifications that can be implemented as an adjunctive to traditional treatment of SD. Methods A case-control retrospective study. Data was obtained from medical records of patients diagnosed with SD. Patients were invited to participate in an online self-reported questionnaire, and dietary intake was assessed using a validated food frequency questionnaire. The controls were collected by distributing the same questionnaire to healthy adult residents living in Jeddah via social media. Results Two hundred sixty-seven participants were included in the study, 59 of whom were SD patients. Participants who reported consuming the following food types once daily had a higher percentage of SD compared to those without SD: a slice of white bread (p=0.002), a cup of rice or pasta (p<0.001), non-acidic fruits (p=0.014), leafy green vegetables (p=0.007), other types of vegetables (p=0.001), roasted or fried nuts (p=0.047), raw nuts (p=0.022) and a cup of coffee (p=0.041). When asked about their impression of what food types triggered or relieved their disease, 29 (49.2%) of the diseased participants reported no flare-ups with any kind of food. On the other hand, the following food types were commonly reported to be associated with SD exacerbation: spicy food (16.9%), sweets (16.9%), fried food (13.5%), dairy products (11.9%), and citrus fruits (10.2%). In contrast, citrus fruits, leafy green vegetables (8.5% for each), and the other types of vegetables (6.8%) were frequently observed with SD improvement. Conclusion Several dietary factors have been associated with SD in our cohort. Thus, our findings could offer new insights into the application of adjuvant dietary measures that might play a role in the improvement of SD symptoms and potentially enhance therapeutic outcomes.