A case of ochronosis successfully treated with the picosecond laser

Picosecond lasers in cosmetic dermatology: where are we now? An overview of types and indications

Q-switched lasers have undeniably revolutionized the field of laser dermatology since four decades ago. Just as the first-generation laser emits its photonic signal in a few nanoseconds, the picosecond laser delivers pulse widths of at least ten times shorter. These devices offer a powerful tool for treating a wide range of skin conditions with a minimal downtime for visible improvement. For the current study, a literature research was performed on the dermatological applications of picosecond laser. The literature searched on this topic between 1999 and 2023 accessible through various platforms produce a result of 62 articles. The included studies have discussed the application of picosecond laser technology in tattoo removal, treatment of epidermal and dermal pigmentation, and collagen remodeling. After sifting the data from the articles into tables, the results were discussed in detail. The study shows a lot of evidence towards the efficacy of picosecond laser, yet it draws attention to its downsides.

Exogenous ochronosis associated with hydroquinone: a systematic review

Exogenous ochronosis is a potential side effect associated with hydroquinone, and treatment is often unsatisfactory. Our study objectives were to review data on hydroquinone-associated ochronosis to determine risk factors for patients experiencing this adverse event. On September 27, 2020 (MEDLINE/PubMed), and October 30, 2020 (Scopus and Web of Science), databases were searched for "ochronosis + hydroquinone" by both authors to reduce risk basis. PRISMA reporting guidelines were used to select 56 articles with a total of 126 patients with hydroquinone-associated ochronosis. Included articles described hydroquinone-associated ochronosis. Articles were excluded if they had irrelevant content, were non-English language text, and were non-case studies. Full text articles were assessed and recorded. Cross-tabulation analysis was performed on categorical data, and Fisher exact test was performed. Ochronosis was most often reported in middle-aged women (53.2%), of African descent (45.2%), Black races (55.5%), and Fitzpatrick skin types V-VI (52.4%). It was most frequently reported with unknown and hydroquinone concentrations greater than 4% (32.5 and 35.7% cases, respectively). Median duration of use was 5 years, with only four cases reported with courses 3 months or shorter and eight cases reported with use 1 year or less. All patients presented with facial blue-black or gray-blue macules in a reticulate, lace-like fashion. Histopathology consistently showed solar elastosis and brownish-yellow, 'banana-shaped' fibers between degenerated collagen fibers of the papillary dermis. Based on these findings, we conclude that hydroquinone in concentrations above 4% and in treatment courses longer than 3 months may be associated with new-onset ochronosis.

Treatment of pigmentary disorders using picosecond laser in Asian patients: A meta-analysis and systematic review

There were many studies evaluating the effect of picosecond (PS) lasers, but no meta-analysis examined the effects of PS laser in the treatment of pigmentary disorders in Asians. The aim of this article was to review the before-after effect of PS laser in Asians for the treatment of pigmentary disorders. PubMed, Embase, and Cochrane library were searched for articles published up to May 2020. The evaluations were summarized into a 4-point scale that ranged from <25% (poor), 25%-50% (fair), 50%-75% (good), and 75%-100% (excellent). Effect sizes (ESs) were calculated according to laser wavelengths and lesion types. There were two randomized controlled trials, three single-arm trials, and three case series, with 200 patients. At 3 months after treatment, of all included patients, 3% (95%CI: 1%-6%) were evaluated as poor or worse, 9% (95%CI: 2%-21%) as fair, 29% (95%CI: 12%-50%) as good, and 56% (95%CI: 28%-83%) as excellent. The 532 and 1064, and 755 nm PS lasers had similar ESs across all four response groups. This meta-analysis suggested that 56% of Asian patients who underwent PS laser for the treatment of pigmentary disorders were evaluated as "excellent" about the pigment clearance by a dermatologist at least 3 months after treatment.

Hydroquinone: myths and reality

Hydroquinone has pharmacological uses in disorders of pigmentation because of its ability to competitively inhibit the enzyme tyrosinase. Our contemporary review presents the strongest evidence supporting the use of hydroquinone with the most effective and tolerable formulations combining hydroquinone, retinoid and corticosteroid (modified Kligman formula or 'triple combination cream'). The risk of exogenous ochronosis is low if prescribed concentrations of ≤ 5 for a limited period with regular monitoring. Dermatologists should reassure patients that with controlled use, hydroquinone can be well-tolerated and safe for a range of hyperpigmentary conditions.