Sensitive skin and rosacea: nosologic framework

A Randomized, Placebo-Controlled Trial of Gamma Linolenic Acid as an Add-on Therapy to Minocycline for the Treatment of Rosacea

Background

A recent study suggested a possible role of skin barrier dysfunction in the pathogenesis of rosacea, which leads to irritation symptoms. Gamma linolenic acid (GLA) is an essential omega-6 fatty acid that is known to restore defective epidermal skin barrier. GLA supplementation has not previously been performed in rosacea patients.

Objective

To investigate the efficacy and safety of adding GLA to minocycline compared to minocycline alone in rosacea patients.

Methods

This prospective, double-blind, randomized, placebo-controlled trial enrolled 31 rosacea patients. They were randomly assigned to receive 320 mg/day of GLA (Evoprim®) (n=16) or placebo (n=15) in addition to 100 mg/day of minocycline for 8 weeks. Investigator's global assessment (IGA) and patient's global assessment (PGA) were used to assess clinical severity at weeks 0, 4, 8, and 12. Biophysical parameters including melanin index, erythema index, transepidermal water loss (TEWL), lipid concentration, and stratum corneum hydration were measured.

Results

In the GLA group, a higher proportion of patients achieved treatment success (IGA≤1) at week 8 (68.75% vs. 33.33%) and patient satisfaction (PGA≥3) at weeks 8 (75.0% vs. 40.0%) and 12 (81.3% vs. 46.6%). Both groups, throughout 12 weeks of treatment, revealed a trend toward improvement in erythema index, melanin index, TEWL, and stratum corneum hydration. Particularly, there was a significant difference in TEWL and stratum corneum hydration over time between the two groups (p=0.033, p=0.003, respectively). No serious adverse event was observed in both groups.

Conclusion

GLA is beneficial as an additional therapeutic option for rosacea patients treated with minocycline.

Distinguishing rosacea from sensitive skin by reflectance confocal microscopy

BACKGROUND

The updated standard classification and pathophysiology of rosacea have provided clear and meaningful evaluation parameters; however, differentiating rosacea from sensitive skin (SS) remained an obstacle for dermatologists around the world, especially in China. Herein, we aimed to find a better characteristic to distinguish rosacea from SS by using reflectance confocal microscopy (RCM).

METHOD

Forty rosacea patients and 143 healthy subjects were recruited in this study. Firstly, a SS questionnaire and a lactic acid sting test were conducted among healthy subjects. Next, two major groups were divided out, including a SS group (40 subjects) and a normal skin control group (NS, 60 subjects). The cutaneous structures of face and fossa cubitalia were imaged by RCM.

RESULTS

We found that more parakeratosis, honeycomb pattern, spongiform edema, and dermal papillae (P < .05) in rosacea patients than that of the NS group, whereas there were no significant differences, were found in rosacea patients and the SS group. Strikingly, we found that rosacea patients have a larger depth of honeycomb pattern than that of SS subjects (P < .05). But, the epidermal thickness of rosacea did not differ from that of SS groups. There was also no significant difference of epidermal thickness and honeycomb structure depth between rosacea patients and NS group.

CONCLUSION

From the RCM images of parakeratosis, honeycomb pattern, spongiform edema, and dermal papillae, we found that RCM might be a faithful tool to distinguish rosacea from NS group. The depth of honeycomb structure of SS was more superficial than rosacea patients, whereas no significant difference between rosacea patients and NS group. RCM may provide a new method for evaluating the development of rosacea although it failed to distinguish rosacea and SS effectively.