Clinical & ultrastructural evaluation of the effect of fractional CO2 laser on facial melasma.

Melasma represents the most obvious and disfiguring change of the face leading to psychological problems especially in females. Ablative lasers have also been used by many professionals to treat melasma, although there is few scientific data supporting this indication. The exact mechanism of action of ablative lasers in melasma is not yet clear enough. We aimed to evaluate the ultrastructural effect of fractional ablative CO2 (FrCo2) laser on facial melasma. Eleven melasma patients evaluated clinically by clinical modified area and severity index (MASI) score, treated by two sessions of fractional CO2 laser one month a part. Two punch biopsies of 2 mm diameter were obtained from all subjects one before and the other 3 months after treatment. All biopsies were analyzed by light and electron microscopy. Clinically, significant improvement of pigmentation and 48% reduction of (MASI) score were observed after two sessions of laser treatments. Light microscopic analysis of specimens revealed significant decrease in melanocyte count after treatment. Electron microscopic analysis of specimens after treatment revealed significant decrease in the number and size of melanocytes and significant decrease or complete absence of melanin granules in the surrounding keratinocytes compared to pre-treatment specimens. No scarring or post inflammatory hyper or hypopigmentation. We concluded that repeated application of Fractional CO2 laser on melasma skin may result in long lasting improvement due to its destructive effect on melanocytes.

Granulysin expression increases with increasing clinical severity of psoriasis.

BACKGROUND: Psoriasis is an erythematosquamous dermatosis, which has strong expression of antimicrobial peptides (AMPs), imparting a high resistance to lesional skin infection. Granulysin is a proinflammatory AMP that has been found in some infection-resistant dermatoses. AIM: To assess granulysin expression in psoriasis. METHODS: Immunohistochemical expression of granulysin was assessed in lesional skin biopsies taken from 30 patients with psoriasis and 10 normal skin specimens from healthy controls (HCs) matched for age, gender and skin site. Granulysin expression was found to be high in 11 patients (36.7%), moderate in 10 (33.3%) and low in 9 (30%). A highly significant (P = 0.001) difference in granulysin expression between patients with psoriasis and HCs was found. There were also significant differences in granulysin expression between patients with low Psoriasis Area and Severity Index (PASI) (≤ 10) and those with high PASI (> 10) (P = 0.001), and between patients with early-onset (< 40 years of age) and those with late-onset (> 40 years of age) disease (P < 0.04). There was a significant (P = 0.001) positive correlation between granulysin expression and PASI (r = 0.84) and a significant (P = 0.02) negative correlation with age of onset (r = -0.38). Patients with psoriasis hadhigh granulysin expression, which increased with increased clinical severity of the disease. CONCLUSIONS: These findings suggest a role for granulysin in psoriasis pathogenesis, and may explain the triggering effect of skin infection in psoriasis. If the pathogenic role of granulysin is substantiated by further studies, granulysin may be a potential target for immunomodulatory therapy for psoriasis.