Minimal Erythema Dose Influenced by Diet in Patients With Psoriasis

According to a study published in Dermatology and Therapy, diet impacts patients with psoriasis undergoing NB-UVB and patients with a lower minimal erythema dose (MED) should be treated in the morning.

Researchers sought to investigate the impact of diet on MED circadian oscillations. In the initial phase, a cohort study compared MED oscillations (morning, afternoon, and evening) before and after a phototherapy cycle in omnivorous patients with psoriasis, along with age-, gender-, skin-type-, MED-, and diet-matched healthy control individuals. Both groups experienced significant MED changes across different timepoints (P < .001), both before and after phototherapy.

Moving to the second phase, the study encompassed patients with psoriasis who achieved clearance through NB-UVB treatment and followed various diets: vegan, vegetarian, paleo, ketogenic, intermittent circadian fasting, and omnivore. A total of 144 patients were included, matched for age, gender, and skin type. The MED circadian oscillations persisted postclearance and were influenced by diet type and time of day (P < .001). Notably, vegans exhibited the lowest MED values, whereas those observing Ramadan fasting showed the highest values during all timepoints.

“Diet, like other ongoing therapies, should be reported in the medical records of patients with psoriasis undergoing NB-UVB and patients with lower MEDs should be preferentially treated in the morning when the MED is higher,” the authors concluded.

Reference
Damiani G, Pacifico A, Scoditti E, et al. Circadian oscillations of minimal erythema dose (MED) are also influenced by diet in patients with psoriasis: a chronomedical study. Dermatol Ther (Heidelb). Published online August 12, 2023. doi:10.1007/s13555-023-00987-z