Low risk of postinflammatory hyperpigmentation in skin types 4 and 5 after treatment with fractional CO2 laser device.

BACKGROUND/OBJECTIVE: Hyperpigmentation occurs in more than 37% of dark-skinned subjects treated with a fully ablative CO2 laser device. This study assessed the risk of postinflammatory hyperpigmentation (PIH) in subjects with skin types 4 and 5 treated once with a specific protocol of treatment using a fractional CO2 laser. METHODS: Seven subjects with photodamaged skin received a single facial treatment using a fractional CO2 laser. Anesthesia was limited to a lidocaine and prilocaine cream for 1 hour before the single-pass treatment. Subjects were evaluated for improvement and PIH on alternate days for 14 days, and at 1 month, 3 months, and 6 months posttreatment. RESULTS: All subjects achieved improvement in their specific skin conditions and in skin texture. Postinflammatory hyperpigmentation was not observed in any subject. Four subjects experienced no pain during treatment, while 3 reported mild pain. Recovery was associated with minimal pain and itching. CONCLUSION: In dark-skinned subjects, fractional CO2 laser treatment and topical anesthesia subjectively improves common skin conditions without PIH.

Sensitivity of Candida albicans germ tubes and biofilms to photofrin-mediated phototoxicity.

Treatment of mucocutaneous and cutaneous Candida albicans infections with photosensitizing agents and light, termed photodynamic therapy (PDT), offers an alternative to conventional treatments. Initial studies using the clinically approved photosensitizer Photofrin demonstrated the susceptibility of C. albicans to its photodynamic effects. In the present study, we have further refined parameters for Photofrin-mediated photodynamic action against C. albicans and examined whether mechanisms commonly used by microorganisms to subvert either antimicrobial oxidative defenses or antimicrobial therapy, including biofilm formation, were operative. In buffer and defined medium, germ tubes preloaded with Photofrin retained their photosensitivity for up to 2 hours, indicating the absence of degradation or export of Photofrin by the organism. The addition of serum resulted in a gradual loss of photosensitivity over 2 hours. In contrast to an adaptive response by germ tubes to oxidative stress by hydrogen peroxide, there was no adaptive response to singlet oxygen-mediated stress by photodynamic action. C. albicans biofilms were sensitive to Photofrin-mediated phototoxicity in a dose-dependent manner. Finally, the metabolic activity of C. albicans biofilms following photodynamic insult was significantly lower than that of biofilms treated with amphotericin B for the same time period. These results demonstrate that several of the mechanisms microorganisms use to subvert either antimicrobial oxidative defenses or antimicrobial therapy are apparently not operative during Photofrin-mediated photodynamic treatment of C. albicans. These observations provide support and rationale for the continued investigation of PDT as an adjunctive, or possibly alternative, mode of therapy against cutaneous and mucocutaneous candidiasis.