Global prevalence and incidence of photodermatoses and prevalence of polymorphic light eruption
Little information is available on the prevalence and incidence of photodermatoses around the world, despite their substantial impact on quality of life. The objective of this study was to carry out a systematic review of the literature to establish what is known about these.
The authors performed a detailed search of Medline, CINAHL and Embase from their inception to 2021, to identify any original population-based studies in the English language reporting the prevalence and/or incidence of photodermatoses.
The authors extracted data and organised it according to geographical location. The risk of bias was assessed using a 10-point risk of bias tool for prevalence studies.
The review included 26 studies, of which 15 reported the prevalence of photodermatoses based on samples of the general population and 11 on prevalence and/or incidence from national and international registry data.
It was found that the global prevalence of polymorphic light eruption (PLE) between countries ranged from 0.65% (China) and 21.4% (Ireland). The pooled estimated prevalence of PLE was 10% among the general population, with this increasing with distance from the equator.
In addition, while photodermatoses are rare, photosensitivity is prevalent in a wide range of locations around the world. In in Egypt, for example, photosensitivity was found in 4% of children and 10% of adults.
The authors concluded that their review showed PLE to be highly prevalent in many populations. Prevalence has a highly significant correlation with increasing northerly or southerly latitude. The population-based studies for photodermatoses suggest they can be prevalent at a range of world locations.
Topical spironolactone in the treatment of acne
Acne vulgaris is the eighth most common skin disease worldwide. It usually presents with inflammatory and noninflammatory skin lesions along with other dermal abnormalities.
Because of its antiandrogenic properties and its inhibition of sebogenesis, oral spironolactone is used to treat the condition.
Evidence shows topical spironolactone has similar efficacy to its oral form, but with fewer adverse events.
The authors wanted to gain an evidence-based understanding of use of topical spironolactone in the treatment of acne vulgaris, and conducted this systematic review to investigate its efficacy and safety.
For their study, they searched PubMed, ClinicalTrials.gov, the Cochrane Library and Google Scholar from date of inception until 18 March 2022. Any clinical trials that had experimented with topical spironolactone in the treatment of acne were included. Those on the effects of oral spironolactone or other topical agents were excluded.
The authors applied the Cochrane risk of bias assessment tool (RoB 2.0, version 2019) to each study and the findings were reported in line with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines.
The literature search produced 600 articles. Five of these were clinical trials, which involved 195 patients, and were included in this review. Of these five trials, two showed a high risk of bias while there were concerns over the other three regarding bias.
The review found that patients treated with topical spironolactone experienced a significant decrease in the number of papules, closed comedones and lesions. Treatment with 5% spironolactone showed a significant decrease in total lesion count compared to placebo.
In 2% of the patients, spironolactone had greater efficacy than clindamycin and reduced the number of comedones, papules and pustules, and acne severity index scores were also considerably lowered.
Spironolactone had no significant effects on skin hydration, sebum, elasticity, melanin and redness.
The authors concluded that topical spironolactone yields better results than other firstline treatments for acne with fewer side effects. However, large-scale clinical trials are needed before spironolactone can be used as the preferred treatment in the management of acne.
Melanoma treatments and effects on mortality
This study examined whether new treatments for cutaneous melanoma were associated with changes in melanoma mortality rate (MMR) trends among US adults.
The aim of this study was to review MMR changes over the long term and determine whether they had any temporal association with the FDA approval of new agents.
To conduct this study, the authors looked at a cross-sectional study that contained population data from the Surveillance, Epidemiology, and End Results (SEER) database and reviewed the age-adjusted MMR trends in adult patients from 1975 to 2019 in the US population. FDA approvals for melanoma treatment were also reviewed by the authors.
The data included were analysed between 15 March and 15 August 2022. Mortality rates were taken from the SEER database, which reported deaths per 100 000 population, age adjusted to the 2000 US standard population.
Following the introduction of newer treatments in 2011, there was a significant reduction in the MMR between 2013 and 2017 in the US—the first decrease seen in 40 years. MMR rates had increased between 1975 to 1988 and there were no statistically significant changes in them between 1988 and 2013. MMR decreased significantly between 2013 and 2017.
The authors concluded that these findings suggest a benefit associated with new, effective pharmacological therapies becoming available in the past decade and suggest that these treatments are associated with a lower MMR in the US population.
They found these data are encouraging and support the continued development of such therapies. However, they said the accessibility of and costs of these treatments need to be addressed.
Allergic contact dermatitis from vitamins in cosmetics
Vitamins, bioactive compounds found in a different types of food, are required by the human body for many biological functions and enzymatic activities.
Because of their antioxidant properties, vitamin derivatives have been synthesised for inclusion in many cosmetic products. This can lead to an increasing incidence of allergic contact dermatitis.
The authors conducted this study to gain an insight into the sensitising role of at least some vitamins used in cosmetics. They believe this may also offer alternatives to patch tests for definitive diagnosis as some vitamins in cosmetics can cause allergy.
The authored conducted a search in accordance with the PRISMA guidelines. Literature searches regarding cases of allergic contact dermatitis linked to vitamins was performed using the Medline, PubMed, Scopus, Embase and Google Scholar databases from January 1940 up to June 2021. A total of 4494 articles were identified. Following screening, 104 articles were found to be relevant.
The authors concluded that allergic contact dermatitis from vitamins is still a largely underestimated issue in cosmetology. They believe this is because several vitamins are considered to be ‘natural’ and therefore safe ingredients.
The authors stated that, according to the literature, almost all of the vitamins contained in topical products could induce allergic reactions, with the exception of vitamins B2 and B9. Patch tests are not standardised, which can lead to difficulties in diagnosis.