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Recent updates in rosacea and acne research

Recent updates in rosacea and acne research

Does Coffee Consumption Affect Rosacea Risk?

Coffee consumption was associated with a decreased risk of rosacea, according to the findings of a recent study.

The study included 82,737 women enrolled in the Nurses’ Health Study II who responded to the question regarding a rosacea diagnosis. Every 4 years, data on coffee, tea, soda, and chocolate consumption were collected. Analyses occurred between June 2017 and June 2018.

During follow up, a total of 4945 cases of rosacea were identified.

The researchers found an inverse association between increased caffeine intake and risk of rosacea after they adjusted for other risk factors (hazard ratio [HR] for highest quintile vs lowest quintile of caffeine intake, 0.76; 95% CI, 0.69-0.84). Additionally, a significant inverse association was found between caffeinated coffee consumption and risk of rosacea (HR for 4 or more servings per day vs less than 1 per month, 0.77; 95% CI, 0.69-0.87). However, this association was not observed for decaffeinated coffee (HR, 0.80; 95% CI, 0.56-0.87).

In addition, caffeine-containing tea, soda, and chocolate were not significantly associated with an increased risk for rosacea.

“Our findings do not support limiting caffeine intake as a means to prevent rosacea,” the researchers concluded. “Further studies are required to explain the mechanisms of action of these associations, to replicate our findings in other populations, and to explore the relationship of caffeine with different rosacea subtypes.” 


Li S, Chen ML, Drucker AM, et al. Association of caffeine intake and caffeinated coffee consumption with risk of incident rosacea in women [published online October 17, 2018]. JAMA Dermatol. doi:10.1001/jamadermatol.2018.3301

Study: Topical Cream Reduces Erythema Associated With Rosacea

Topical oxymetazoline cream 1.0% (Rhofade) effectively treated patients with moderate to severe erythema of rosacea, according to the findings of a recent study published in the Journal of American Academy of Dermatology.

The researchers analyzed data from two identically designed phase 3 trials, which randomly assigned 885 patients to receive once daily oxymetazoline or vehicle for 29 days followed by a 28-day follow-up period. The primary outcome was the proportion of patients who achieved an improvement of 2 or greater in Clinician Erythema Assessment (CEA) and Subject Self-Assessment (SSA) scores at 3, 6, 9, and 12 hours posttreatment and on day 29 compared with baseline.

Overall, significantly more patients who received oxymetazoline achieved a grade 2 or greater improvement on CEA and SSA scores compared with those in the vehicle group. Oxymetazoline showed greater improvements in individual CEA and SSA scores and digital image analysis of facial erythema compared with vehicle.

In addition, the incidence of treatment-emergent adverse events was low, with 16.4% of patients treated with oxymetazoline and 11.8% of patients treated with vehicle experiencing an adverse event. During the follow-up period, no clinically relevant worsening of erythema was observed.

“Oxymetazoline effectively reduced moderate to severe persistent facial erythema of rosacea and was well tolerated,” the researchers concluded. 


Stein-Gold L, Kircik LH, Draelos ZD, et al. Efficacy and safety of topical oxymetazoline cream 1.0% for treatment of persistent facial erythema associated with rosacea: findings from the two phase 3, 29-day, randomized, controlled REVEAL trials [published online February 4, 2018]. J Am Acad Dermatol.

Common Acne Treatment Lacks Strong Evidence

While oral isotretinoin is recommended by the American Academy of Dermatology for moderate to severe acne,1 the drug has been associated with several adverse effects, including birth defects, depression, and inflammatory bowel disease. It includes black box warnings and requires enrollment in iPLEDGE, a risk evaluation and mitigation strategy, for patients prescribed the therapy.

In a recent meta-analysis, researchers were unable to determine both the efficacy and safety of oral isotretinoin due to low-quality evidence in the majority of studies.2 They searched the literature and identified 31 studies that included a total of 3836 participants with mild to severe acne. Studies included in the analysis compared various doses of isotretinoin, oral isotretinoin with placebo, as well as other treatments including antibiotics.

“Evidence was low-quality for most outcomes assessed,” the researchers wrote, including reported adverse events, inflammatory lesion counts, and improvements in severity.

They found no difference in the number of inflammatory lesions in three studies that compared isotretinoin with any oral antibiotic plus topical therapy. However, evidence was of low quality. One adverse event (Stevens-Johnson syndrome) associated with isotretinoin treatment was reported.

The researchers found slight improvements in acne severity when assessed by physician’s global evaluation, as well as less serious adverse events associated with isotretinoin, including dry skin, cheilitis, nausea, and vomiting. This evidence was also of low quality.

Fourteen studies that compared different doses of isotretinoin were analyzed. In two studies, the researchers found greater improvements associated with higher doses of isotretinoin. Another study showed that continuous, daily use of either low or conventional dosing of isotretinoin improved acne severity. In addition, a study found that conventional dosing lowered lesion count compared with low dosing, but “this was based on very low-quality evidence, indicating uncertainty,” the researchers wrote.

Adverse events reported in the 14 studies were less serious and included dry skin, hair loss, and itching but the researchers are uncertain if there were any differences between dosing as evidence was low or very low quality. No birth defects were reported in any of the studies included in analysis.

“The overall quality of evidence for all of our key outcomes was low, due to serious limitations of study design and the limited amount of data,” the researchers concluded. “Thus, we are uncertain about the effects of oral isotretinoin on people with acne.”

The researchers noted that future studies should clearly report long- and short-term standardized assessment of improvements in total inflammatory lesion counts, participant-reported outcomes, and safety. In addition, “oral isotretinoin for acne that has not responded to oral antibiotics plus topical agents needs further assessment, as well as different dose/regimens of oral isotretinoin in acne of all severities,” they wrote. 


1. Zaenglein AL, Pathy AL, Schlosser BJ, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2016;74(5):945-73.e33.

2. Costa CS, Bagatin E, Martimbianco ALC, et al. Oral isotretinoin for acne [published online November 24, 2018]. Cochrane Database Syst Rev. doi:10.1002/14651858.CD009435.pub2

Study: Obesity Increases Rosacea Risk in Women

Currently, little data exists about the relationship between obesity and rosacea. To explore this potential relationship further, the researchers evaluated data on 89,886 women who had participated in the 1991-2005 Nurses’ Health Study II. Follow-up lasted 14 years.

Information about patients’ history of clinician-diagnosed rosacea as well as year of diagnosis was collected in 2005.

Results showed that 5249 incident cases of rosacea had developed throughout follow-up. Ultimately, the researchers found that individuals with an elevated body mass index (BMI) had a higher risk for rosacea. The hazard ratio (HR) of rosacea was 1.48 for individuals with a BMI of at least 35.0 kg/m2, compared with those with a BMI of 21.0 kg/m2 to 22.9 kg/m2.

The researchers observed a trend toward a higher risk for rosacea among individuals who had gained weight after age 18 years (HR 1.04 per 10-lb weight gain). Furthermore, the risk for rosacea was also significantly higher among individuals with a larger waist circumference and hip circumference. These associations were independent of BMI, the researchers noted.

“Measures of obesity were significantly associated with an increased risk for incident rosacea,” the researchers concluded. 


Li S, Cho E, Drucker AM, Qureshi AA, Li WQ. Obesity and risk for incident rosacea in US women. J Am Acad Dermatol. 2017;77(6):1083-1087.e5.

Alternative Acne Treatment Effectively Reduces Lesions

A cream formulated with tea tree oil, Aloe vera, and propolis effectively reduced acne scars, erythema, and lesions, according to the findings of a recent study.

While antibiotics are standard treatment for acne, alternative treatment options are needed due to the rise of antibiotic resistance. One potential alternative is the use of plants with known innate antimicrobial action.

In the study, the researchers assessed the efficacy of a cream formulated with 20% propolis, 3% tea tree oil, and 10% Aloe vera (PTAC) among participants with mild to moderate acne. Participants were randomized to receive either PTAC (n=20), erythromycin cream (n=20), or placebo (n=20). The researchers evaluated acne lesion counts through noninvasive measurements, including the Acne Severity Index (ASI), and macrophotography at baseline, 15 days, and 30 days posttreatment.

The researchers found statistically significant differences in all clinical and instrumental values between placebo, erythromycin cream, and PTAC, except for sebometry, pHmetry, and erythema index values, measured on healthy skin. Compared with participants treated with placebo, those treated with PTAC or erythromycin cream experienced greater erythema reduction 15 days and 30 days after treatment.

PTAC was found to better reduce erythema scars and speed up healing time, which was seen as early as the first 15 days of treatment. Participants treated with PTAC experienced significant reductions in ASI and total lesion count compared with those treated with erythromycin cream. After 15 days and 30 days of treatment, ASI scores were significantly reduced by 31.6% and 66.7%, respectively, among those treated with PTAC. Whereas, ASI scores among those treated with erythromycin cream were reduced by 27.1% after 15 days and 49.7% after 30 days of treatment.

The mean TLC value among participants in the PTAC group decreased significantly by 33.56% and 63.7% after 15 days and 30 days of treatment, respectively, while those in the erythromycin cream group decreased by 23.6% and 46.5%.

“In this study, it has been shown that the cream containing propolis, tea tree oil, and aloe vera is more effective in reducing acne compared to the preparation of synthetic origin such as erythromycin,” the researchers concluded. “In addition, the preparation based on natural product has been shown to have greater function in reducing erythema. Further studies are highly recommended using larger number of patients with a more extended experimental period.” 


Mazzarello V, Donadu MG, Ferrari M, et al. Treatment of acne with a combination of propolis, tea tree oil, and Aloe vera compared to erythromycin cream: two double-blind investigations. Clin Pharmacol. 2018;10:175-181. doi:10.2147/CPAA.S180474

Treating Acne with Systemic Antibiotics Alters Skin Microbiota

Systemic antibiotic treatment for acne using oral minocycline is associated with changes in the diversity of skin microbiota, according to a study published online in JAMA Dermatology.

“Given the widespread use of systemic antibiotics for treatment of moderate to severe acne, it is important to understand the associations of such antibiotic use with changes not only in Cutibacterium acnes (formerly Propionibacterium acnes),” the researchers wrote, “but also in the complete bacterial community of the skin.”

The longitudinal cohort study included 4 women with acne vulgaris and no recent use of systemic or topical acne treatments. The women, ages 25, 25, 29, and 35 years, were prescribed oral minocycline, 100 mg, twice a day over 4 weeks. Researchers examined skin microbiota on the forehead, cheek, and chin at baseline, at 4 weeks after starting minocycline, and at 1 and 8 weeks after discontinuing minocycline.

After 4 weeks of treatment, researchers identified a 1.4-fold reduction in the level of Cutibacterium acnes across all 4 participants, with recovery after minocycline was discontinued. They also reported a transient 5.6-fold increase in the relative abundance of Pseudomonas species immediately following antibiotic treatment.

Eight weeks after antibiotic cessation, researchers found a persistent 1.7-fold increase in the relative abundance of Streptococcus species as well as a 4.7-fold decrease in the relative abundance of Lactobacillus species.

“Understanding the association between systemic antibiotic use and skin microbiota,” the researchers wrote, “may help clinicians decrease the likelihood of skin comorbidities related to microbial dysbiosis.” 


Chien AL, Tsai J, Leung S, et al. Association of systemic antibiotic treatment of acne with skin microbiota characteristics [published online February 13, 2019]. JAMA Dermatology. doi:10.1001/jamadermatol.2018.5221

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