Silicone gel enhances the efficacy of Er:YAG laser treatment for atrophic acne scars: A randomized,split-face,evaluator-blinded,placebo-controlled,comparative trial

Background: The effect of topical silicone gel has been studied to prevent scars from burn, postoperative wound and to treat hypertrophic scars. No previous studies have been done to evaluate the efficacy of topical silicone gel on atrophic acne scars. Material and methods: Nineteen patients were treated with three sessions of ablative Er:YAG laser with 1-month intervals. Following each laser treatment, the randomlyassigned silicone gel or placebo was applied in split-face manner. Objective assessments, which included roughness, smoothness, hydration, transepidermal water loss were measured at baseline and prior to each treatment. Subjective assessments by dermatologists and subjects were done at baseline and 1 month after last laser treatment. Results: The laser treatments were well tolerated and resulted in clinical improvements. Topical silicone gel treatment resulted in significantly less roughness at weeks 4 and 12 compared with placebo (p < 0.05). Conclusion: Adding topical silicone gel to ablative Er:YAG laser treatment may provide additional benefits in improving acne scars.     

Addressing the conundrums of p‐phenylenediamine hair dye allergy by applying Friedmann's principles of contact sensitization

In the first conundrum, permanent hair dyeing involves the use of aromatic amines such as p‐phenylenediamine (PPD), whose oxidation is pivotal to the dyeing process, but also generates potent allergens. Despite prolonged efforts by industry to search for safer alternatives, hair dyeing is still reliant on this type of aromatic amine. In the second conundrum, patch testing with 1% PPD remains the most useful screen for hair dye contact allergy. However, there is a very small but real risk of actively sensitizing the patient. Lowering the PPD concentration below 1% significantly reduces test sensitivity and diagnostic utility. Here, we argue that by applying Friedmann's principles of contact sensitization each conundrum can be addressed from a new perspective. These principles indicate that, when the exposed area of skin is small (<1 cm²), induction of contact allergy is sharply reduced, whereas elicitation of allergy is unaffected. Careful reflection on this principle suggests that we can predict where hair dye sensitization is most likely to occur, indicates a strategy to reduce the chance of contact sensitization occurring in consumers as a result of hair dyeing, and how we might mitigate the risk of active sensitization resulting from diagnostic patch testing.