Role of Serum Melatonin and Oxidative Stress in Childhood Atopic Dermatitis: A Prospective Study.

BACKGROUND: Many factors have been implicated in the pathogenesis of atopic dermatitis (AD) and recently the role of oxidative damage has been postulated. OBJECTIVES: To study the levels of oxidants and antioxidants including melatonin in the blood of children with AD and their association with the severity of AD. METHODS: Thirty patients with atopic dermatitis, aged 6 months to 12 years, and equal number of age and sex-matched controls were included. Clinical characteristics and baseline severity assessment using SCORAD (scoring atopic dermatitis) severity index were noted. Blood superoxide dismutase, blood glutathione peroxidase, serum malondialdehyde, and serum melatonin levels were measured in cases and controls and results were compared. RESULTS: The serum levels of malondialdehyde and melatonin were significantly higher among the cases compared to controls. The blood levels of superoxide dismutase and glutathione peroxidase were higher in cases but the difference with controls was not statistically significant. There was no significant correlation between these markers and the severity of the disease. CONCLUSIONS: Oxidative stress was increased in cases of childhood AD compared to the control group in this study. No correlation between oxidative stress and the severity of the disease was found. Larger studies are warranted.

Melatonin and oxidative stress in melasma - an unexplored territory; a prospective study.

BACKGROUND: Melasma, an acquired disorder of hyperpigmentation, is the most common pigmentary disorder in India. Many factors are implicated in the pathogenesis, and recently the role of oxidative damage including melatonin has been postulated. This study was undertaken to evaluate the role of oxidative stress and serum melatonin in pathogenesis of melasma. METHODS: Seventy-five patients with melasma and an equal number of age and sex-matched controls were included in the study. Clinical characteristics were noted, and baseline severity assessment using modified Melasma Area and Severity Index (MASI) was done in all patients. Serum melatonin, catalase, protein carbonyl, and nitric oxide levels were measured and compared between cases and controls. RESULTS: The serum levels of melatonin and catalase were significantly lower among the cases as compared to controls, while the serum levels of protein carbonyl and nitric oxide were significantly higher in cases compared to controls. There was no statistically significant correlation between these markers of oxidative stress and severity of the disease. CONCLUSIONS: Oxidative stress is increased in patients with melasma compared to the control group in this study. A state of melatonin deficit also exists in patients with melasma. No correlation between the oxidative stress and severity of the disease was found. Further and larger studies including therapeutic trials with powerful antioxidants are warranted.