Hydrophobically modified polymers can minimize skin irritation potential caused by surfactant-based cleansers

Five dimensions of cleansing: A holistic view on the facets and importance of skin cleansing

Cleansing is an important human ritual practised for hygiene, well-being and relaxation over centuries. As part of body care it is often taken for granted, yet its relevance cannot be underestimated. Although cleansing the skin may seem trivial to some, it is accepted, that this fundamental function of skin cleansing products is highly complex, diverse and crucial for a variety of reasons in the personal, public, healthcare and dermatological settings. Employing a comprehensive and strategic approach in viewing cleansing and its rituals, supports innovation, understanding and development. Apart from being a fundamental function, as far as we know, there is no comprehensive presentation of skin cleansing with all its effects besides 'removing dirt'. To our knowledge, comprehensive analyses on the multi-dimensional facets of skin cleansing are either rare or not published. Against this background, we examine the importance of cleansing in terms of function, relevance and concepts. First, the key functions and efficacies of skin cleansing were investigated by literature research. Based on this survey, the functions were analysed, sorted and merged and a novel approach to skin cleansing 'dimensions' was developed. Herewith, we took into consideration the evolution of skin cleansing in terms of concept evolution, complexity and testing methods for cleansing products and their claims. Several multi-dimensional functions of skin cleansing were identified and then established into five skin cleansing dimensions, namely: hygienic and medical importance; socio-cultural and interpersonal relevance; mood, emotion and well-being; cosmetic and aesthetic function; corneobiological interactions. It became obvious, that these five dimensions with their corresponding 11 sub-dimensions, are influenced by each other throughout history by culture and society, technical progress, scientific knowledge and consumer trends. This article presents the enormous complexity of skin cleansing. Skin cleansing has evolved from basic care up to a highly complex and diverse cosmetic product category in terms of technology, efficacy and usage routine(s). In view of future challenges, such as the effects of climate and associated lifestyle changes, the development of skin cleansing will remain an exciting and important topic and thus will finally, again, further increase the complexity of skin cleansing itself.

S2k guideline: Rosacea

This updated and upgraded S2k guideline deals with the diagnosis and treatment of rosacea, which is a common, chronic inflammatory skin disease mostly affecting the face. Initially, rosacea is characterized by recurrent erythema, telangiectasia and flushing. Later, the inflammatory component predominates, with persistent erythema with follicular papules, papulopustules and pustules. The development of phyma, which usually occurs on the acral localizations, is the most severe manifestation. For the treatment of rosacea, the interdisciplinary guideline committee, with representatives of the German Dermatological Society (DDG), the Professional Association of German Dermatologists (BVDD), the German Opthalmological Society (DOG), the Society for Dermopharmacy (GD), the Swiss Society for Dermatology and Venereology (SGDV) and the German Rosacea Aid e. V., recommends the avoidance of trigger factors and topical applications of metronidazole, azelaic acid or ivermectin. For symptomatic treatment of persistent centrofacial erythema, the topical vasoconstrictors brimonidine or oxymetazoline can also be used. Systemic therapy is recommended for therapy-resistant and severe forms of rosacea papulopustulosa. The drug of choice is low-dose doxycycline. Alternatively, low-dose isotretinoin can be recommended. Ocular rosacea should be treated with lid margin hygiene. For topical treatment, ciclosporin eye drops, azithromycin, ivermectin or metronidazole are suggested.

Impeding the Medical Protective Clothing Contamination by a Spray Coating of Trifunctional Polymers

The risk of fomite-mediated transmission in the clinic is substantially increasing amid the recent COVID-19 pandemic as personal protective equipment (PPE) of hospital workers is easily contaminated by direct contact with infected patients. In this context, it is crucial to devise a means to reduce such transmission. Herein, we report an antimicrobial, antiviral, and antibiofouling trifunctional polymer that can be easily coated onto the surface of medical protective clothing to effectively prevent pathogen contamination on the PPE. The coating layer is formed on the surfaces of PPE by the simple spray coating of an aqueous solution of the trifunctional polymer, poly(dodecyl methacrylate (DMA)-poly(ethylene glycol) methacrylate (PEGMA)-quaternary ammonium (QA)). To establish an optimal ratio of antifouling and antimicrobial functional groups, we performed antifouling, antibacterial, and antiviral tests using four different ratios of the polymers. Antifouling and bactericidal results were assessed using Staphylococcus aureus, a typical pathogenic bacterium that induces an upper respiratory infection. Regardless of the molar ratio, polymer-coated PPE surfaces showed considerable antiadhesion (∼65-75%) and antibacterial (∼75-87%) efficacies soon after being in contact with pathogens and maintained their capability for at least 24 h, which is sufficient for disposable PPEs. Further antiviral tests using coronaviruses showed favorable results with PPE coated at two specific ratios (3.5:6:0.5 and 3.5:5.5:1) of poly(DMA-PEGMA-QA). Moreover, biocompatibility assessments using the two most effective polymer ratios showed no recognizable local or systemic inflammatory responses in mice, suggesting the potential of this polymer for immediate use in the field.

Skin Cleansing without or with Compromise: Soaps and Syndets

Products designed to cleanse the skin commonly do so through surfactant action, which leads to the lowering of the surface tension of the skin to facilitate the removal of dirt from its surface. Skin cleansers generally come in one of two types: soap-based and synthetic detergents, or syndets. While the latter can effectively maintain the native skin structure, function and integrity, the former tends to negatively affect the skin by causing barrier disruption, lipid dissolution and pH alteration. Despite this, soap is still often preferred, possibly due to the negative connotations around anything that is not perceived as 'natural'. It is, therefore, important that the science behind cleansers, especially those designed for the maintenance of healthy skin and the management of common skin conditions such as eczema, be understood by both formulators and end-users. Here, we carefully weigh the advantages and disadvantages of the different types of surfactant-the key ingredient(s) in skin cleansers-and provide insight into surfactants' physicochemical properties, biological activity and potential effects. Fine-tuning of the complex characteristics of surfactants can successfully lead to an 'optimal' skin cleanser that can simultaneously be milder in nature, highly effective and beneficial, and offer minimal skin interference and environmental impact.

The History of Surfactants and Review of Their Allergic and Irritant Properties

Surfactants, many of which are used as detergents, can be found in many common household items, such as shampoos, conditioners, soaps, and cosmetics. One should recognize the multitude of surfactants that are used in today's products to identify any potential allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD). Given their abundance in everyday products, it is understandable that many cases of occupational contact dermatitis that arise can be attributed to surfactants. The products most connected with ACD are cocamidopropyl betaine, oleamidopropyl dimethylamine, decyl glucoside, 3-dimethylaminopropylamine, amidoamine, and cocamide diethanolamine. Similarly, the most common surfactant-related causes of ICD are sodium lauryl sulfate and benzalkonium chloride. It is important for dermatologists to identify the causes and differentiate between the two, to adjust treatments and products accordingly. Here, the most frequently used surfactants, as well as their correlation between ACD and ICD, will be reviewed.

Towards Optimal pH of the Skin and Topical Formulations: From the Current State of the Art to Tailored Products

Acidic pH of the skin surface has been recognized as a regulating factor for the maintenance of the stratum corneum homeostasis and barrier permeability. The most important functions of acidic pH seem to be related to the keratinocyte differentiation process, the formation and function of epidermal lipids and the corneocyte lipid envelope, the maintenance of the skin microbiome and, consequently, skin disturbances and diseases. As acknowledged extrinsic factors that affect skin pH, topically applied products could contribute to skin health maintenance via skin pH value control. The obtained knowledge on skins’ pH could be used in the formulation of more effective topical products, which would add to the development of the so-called products ‘for skin health maintenance’. There is a high level of agreement that topical products should be acidified and possess pH in the range of 4 to 6. However, formulators, dermatologists and consumers would benefit from some more precise guidance concerning favorable products pH values and the selection of cosmetic ingredients which could be responsible for acidification, together with a more extensive understanding of the mechanisms underlaying the process of skin acidification by topical products.

Antioxidant and Cytoprotective Properties of Plant Extract from Dry Flowers as Functional Dyes for Cosmetic Products

Nowadays, natural dyes are expected by the cosmetic and food industries. In contrast to synthetic dyes, colorants derived from natural sources are more environmentally friendly and safer for human health. In this work, plant extracts from Gomphrena globasa L., Clitoria ternatea L., Carthamus tinctorius L., Punica granatum L. and Papaver rhoeas L. as the natural and functional dyes for the cosmetics industry were assessed. Cytotoxicity on keratinocyte and fibroblast cell lines was determined as well as antioxidant and anti-aging properties by determining their ability to inhibit the activity of collagenase and elastase enzymes. In addition, the composition of the extracts was determined. The obtained extracts were also applied in face cream formulation and color analyses were performed. It has been shown that the obtained extracts were characterized by no cytotoxicity and a high antioxidant potential. The extracts also show strong ability to inhibit the activity of collagenase and moderate ability to inhibit elastase and provide effective and long-lasting hydration after their application on the skin. Application analyses showed that the extracts of P. rhoeas L., C. ternatea L. and C. tinctorius L. can be used as effective cosmetic dyes that allow for attainment of an intense and stable color during the storage of the product. The extracts of P. granatum L. and G. globasa L., despite their beneficial effects as active ingredients, did not work effectively as cosmetic dyes, because cosmetic emulsions with these extracts did not differ significantly in color from emulsions without the extract.

Identifying and appraising patient-reported outcome measures on treatment satisfaction in acne: a systematic review

BACKGROUND

After dermatitis, acne is the next skin disease to contribute most to the burden of skin diseases worldwide. Recently, seven core outcome domains have been identified, which together form an Acne Core Outcome Set (ACORN). One of these was satisfaction with acne treatment.

OBJECTIVES

To identify studies that described the development of patient-reported outcome measures (PROMS), evaluated one or more measurement properties of a PROM, or evaluated the interpretability of a PROM in patients with acne regarding treatment satisfaction.

METHODS

The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) search strategy for identifying PROMS on acne treatment satisfaction was used. We searched PubMed, MEDLINE, Embase, LILACS, Web of Science, Cochrane Library, Emcare, PsycINFO and Academic Search premier (June 2020). Study selection, data extraction and assessment of methodological quality according to COSMIN guidance were carried out independently by two authors.

RESULTS

Only one study could be included, describing the development of a treatment satisfaction measure in patients with acne. The development was assessed as inadequate and data on measurement properties were lacking. Additionally, we found 188 studies reporting treatment satisfaction solely as an outcome, using a wide variety of methods, none of them standardized or validated.

CONCLUSIONS

We could not find a PROM on treatment satisfaction to recommend for a core outcome set in acne. There is an unmet need for a PROM on treatment satisfaction in acne that is robustly developed, designed and validated.

Online comment-based prediction of cosmetic ingredient's sensory irritation using gradient boosting algorithm

BACKGROUND

The worldwide prevalence of "sensitive skin" group is estimated at being close to 40%. The main trigger for sensitive skin is the misuse of cosmetics products. Majority of the in vitro studies on cosmetic ingredients developed for topical application to the skin are not able to describe sensory irritation, such as stinging, burning, itching, and tingling. Besides, most of the in vivo tests often encounter problems such as limited number of subjects and usage scenarios deviate from reality.

OBJECTIVE

A gradient boosting algorithm is adopted in our context to integrate multisource of information including skin types, sensory response, and cosmetics ingredients to predict sensory irritation.

METHOD

In this study, online comments were preprocessed to construct a multi-dimensional structured data including skin types, sensory response, and cosmetics ingredients. A gradient boosting regression model was developed where sensory response was predicted based on the abovementioned structured input. The predictions were validated by in vivo test and were shown favorably when comparing with the state-of-the-art results from related works.

RESULT

46 007 samples were collected after data cleaning and were used in model developing. Results showed that the model was capable to predict the sensory response of 16 skin types to different ingredients (R = 0.71, P < 10^-10 ). In addition, this model was validated using data from in vivo studies and presented a value of 75% on specificity, 88.9% on sensitivity, and 82.4% on accuracy.

CONCLUSION

Our approach that is based on a variant of the gradient boosting algorithm provided an adequate solution for understanding the sensory irritation of cosmetic ingredients.

Interventions for rosacea based on the phenotype approach: an updated systematic review including GRADE assessments

BACKGROUND

Rosacea is a common chronic facial dermatosis. Classification of rosacea has evolved from subtyping to phenotyping.

OBJECTIVES

To update our systematic review on interventions for rosacea.

METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, Science Citation Index and ongoing trials registers (March 2018) for randomized controlled trials. Study selection, data extraction, risk-of-bias assessment and analyses were carried out independently by two authors. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was used to assess certainty of evidence.

RESULTS

We included 152 studies (46 were new), comprising 20 944 participants. Topical interventions included brimonidine, oxymetazoline, metronidazole, azelaic acid, ivermectin and other topical treatments. Systemic interventions included oral antibiotics, combinations with topical treatments or other systemic treatments. Several studies evaluated laser or light-based treatment. We present the most current evidence for rosacea management based on a phenotype-led approach.

CONCLUSIONS

For reducing temporarily persistent erythema there was high-certainty evidence for topical brimonidine and moderate certainty for topical oxymetazoline; for erythema and mainly telangiectasia there was low-to-moderate-certainty evidence for laser and intense pulsed light therapy. For reducing papules/pustules there was high-certainty evidence for topical azelaic acid and topical ivermectin; moderate-to-high-certainty evidence for doxycycline 40 mg modified release (MR) and isotretinoin; and moderate-certainty evidence for topical metronidazole, and topical minocycline and oral minocycline being equally effective as doxycycline 40 mg MR. There was low-certainty evidence for tetracycline and low-dose minocycline. For ocular rosacea, there was moderate-certainty evidence that oral omega-3 fatty acids were effective and low-certainty evidence for ciclosporin ophthalmic emulsion and doxycycline.

Reduction of Irritation Potential Caused by Anionic Surfactants in the Use of Various Forms of Collagen Derived from Marine Sources in Cosmetics for Children

Surfactants, which are the basic ingredients in washing cosmetics, can cause skin irritation. In the case of washing cosmetics intended for children, it is necessary to select the composition in such a way as to ensure maximum reduction or even elimination of the irritant effect of the final product. The paper attempts to improve the safety of bath cosmetics for children by introducing: collagen amino acids (150 Da), hydrolysed collagen (12000 Da) and soluble collagen (300 000 Da). Zein value, bovine albumin, and human keratinocyte cell line studies have shown a significant decrease in the irritant potential of the compositions following the introduction of the proposed additives, which is more pronounced with the increase in the molecular weight of marine collagen. An important part of this work is a mechanism proposed by the authors, according to which the addition of the proposed additives can increase safety of the application of cosmetics for children.

Differential behavior of sodium laurylsulfate micelles in the presence of nonionic polymers

HYPOTHESIS

Theory and practice have proven that the cleansing properties and irritation potential of surfactants can be controlled with the addition of co-surfactants or polymers. The size of the surfactant-polymer nanoassembly, which differs from the pure surfactant micelle, has been postulated to be the cause of the differences in a surfactant system's ability to disrupt the skin barrier. However, a firm structure-function relationship connecting polymer and surfactant under a consumer relevant condition is yet to be established. It is therefore hypothesized that apart from the size, the shape and the chemical nature of the polymer might play crucial roles.

EXPERIMENTS

We used combined small-angle neutron scattering, nuclear magnetic resonance spectroscopy, tensiometry, and dye solubilization methods to investigate the shape, size, and intermolecular interactions involved in sodium laurylsulfate-based systems in the presence of two industrially important and chemically distinct polymers, polyethylene glycol and polyvinyl alcohol, adopting a consumer relevant protocol.

FINDINGS

Apart from size, shape and inter-micellar interactions fine-tuned by the presence of the polymers are found to be the important factors. Secondly, the physicochemical property of the polymer including chemical structure, conformation, hydrophilicity, presence of side groups, all can have crucial influence on polymer-surfactant interaction, micelle formation, and micelle stability.

Interactions between surfactants and the skin - Theory and practice

One of the primary causes of skin irritation is the use of body wash cosmetics and household chemicals, since they are in direct contact with the skin, and they are widely available and frequently used. The main ingredients of products of this type are surfactants, which may have diverse effects on the skin. The skin irritation potential of surfactants is determined by their chemical and physical properties resulting from their structure, and specific interactions with the skin. Surfactants are capable of interacting both with proteins and lipids in the stratum corneum. By penetrating through this layer, surfactants are also able to affect living cells in deeper regions of the skin. Further skin penetration may result in damage to cell membranes and structural components of keratinocytes, releasing proinflammatory mediators. By causing irreversible changes in cell structure, surfactants can often lead to their death. The paper presents a critical review of literature on the effects of surfactants on the skin. Aspects discussed in the paper include the skin irritation potential of surfactants, mechanisms underlying interactions between compounds of this type and the skin which have been proposed over the years, and verified methods of reducing the skin irritation potential of surfactant compounds. Basic research conducted in this field over many years translate into practical applications of surfactants in the cosmetic and household chemical industries. This aspect is also emphasized in the present study.

The science behind skin care: Cleansers

Two of the most important skin care categories with profound dermatologic implications are cleansers and moisturizers. Cleansers are composed of alkaline soaps or the less barrier-damaging synthetic detergents, known as syndets. The lower skin irritation and dryness found with syndets are related to their reduced tendency to cause protein denaturation due to the charge density of protein-bound micelle-like surfactant aggregates. Many cleansing formulations are available for purchase to meet hygiene needs varying by sex, age, ethnicity, occupation, environment, personal preferences, and the presence or absence of skin disease. This discussion covers the science of skin cleansing.

Improvement in the Safety of Use of Hand Dishwashing Liquids Through the Addition of Hydrophobic Plant Extracts

We investigated the effect of hydrophobic extract concentration on the safety of using hand dishwashing liquids (HDL). A series of formulations was prepared, differing in the concentration of the hydrophobic chamomile extract obtained in supercritical CO₂ conditions (from 0 to 0.7 %). We found that an increase in the concentration of the extract led to a decrease in the zein number, and reduced changes in the pH level of bovine serum albumin solution (i.e., two parameters determining the irritant activity of the formulations). It was also found that the additives reduced transepidermal water loss and improved the skin hydration level. Based on the findings of the study, a mechanism has been proposed, according to which hydrophobic plant extracts form aggregates in the volume phase of the washing bath. The surface of the aggregates is the adsorption area for surfactant monomers responsible for the irritant effect. Increasing the addition of the extract was shown to reduce the negative impact of the formulations on the skin of the hands, thus contributing to a greater safety of use of HDL.

The role of topical dermocosmetics in acne vulgaris

Acne is a common chronic inflammatory disease and treatment modalities based on acne severity are well established. The role of dermocosmetics in dermatology, and in particular acne, is becoming more important as more research elucidates the mechanisms of action of products in the pathogenesis of acne. Dermocosmetics have the potential to be used as monotherapy or in combination with medical treatment. Therefore, it has become important for dermatologists to understand dermocosmetics to effectively and appropriately advise patients on their use. The objective of this review was to provide new insights into the role of traditional and novel ingredients in dermocosmetics for the treatment of acne, based on the authors' objective assessment of the published literature. The type of products discussed include: those which have a sebostatic effect, such as topical antioxidants and niacinamide; agents targeting abnormal keratinization, such as salicylic acid, lipo-hydroxy acid, alpha-hydroxy acids, retinol-based products and linoleic acid; agents targeting Propionibacterium acnes, such as lauric acid; and anti-inflammatory agents such as nicotinamide, alpha-linolenic acid and zinc salts. Despite the scientific advances in understanding these cosmetic ingredients, there still remains a lack of rigorous controlled studies in this area.

Role of cleansers in the management of acne: Results of an Italian survey in 786 patients

BACKGROUND

Modern therapy of acne is based also on moisturizers, cleansers and sunscreens. However, a few studies have been published on cleansers, and never in Italy.

OBJECTIVE

We decided to carry out an epidemiological study on the knowledge, beliefs and perceptions of acne patients regarding cleansers.

METHODS

The survey has been carried out in Italy in 2013-2014. A group of patients with acne completed a questionnaire which included 10 questions.

RESULTS

One hundred and eighteen dermatologists and 786 evaluable acne patients attended the survey. Approximately 70% of patients use a specific anti-acne cleanser. This cleanser is suggested in 57% of cases by a dermatologist. The patients buy this cleanser at the pharmacy (77% of cases). More than 62% of patients are satisfied about this cleanser. More than 66% of patients use the cleanser twice daily. The length of washing is less than one minute in 48% of patients. More than 66% of patients believe that the cleanser has a therapeutical role.

CONCLUSION

The results of this survey cannot be compared with other studies because of the lack of similar studies about this topic. These results suggest that a sample of Italian acne patients consider cleansers as an important adjuvant treatment in acne.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some people. A range of treatment options are available but it is unclear which are most effective.

OBJECTIVES

To assess the efficacy and safety of treatments for rosacea.

SEARCH METHODS

We updated our searches, to July 2014, of: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 6), MEDLINE (from 1946), EMBASE (from 1974) and Science Citation Index (from 1988). We searched five trials registers and checked reference lists for further relevant studies.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, risk of bias assessment and analyses were carried out independently by two authors.

MAIN RESULTS

We included 106 studies, comprising 13,631 participants. Sample sizes of 30-100 and study duration of two to three months were most common. More women than men were included, mean age of 48.6 years, and the majority had papulopustular rosacea, followed by erythematotelangiectatic rosacea.A wide range of comparisons (67) were evaluated. Topical interventions: metronidazole, azelaic acid, ivermectin, brimonidine or other topical treatments. Systemic interventions: oral antibiotics, combinations with topical treatments or other systemic treatments, i.e. isotretinoin. Several studies evaluated laser or light-based treatment.The majority of studies (57/106) were assessed as 'unclear risk of bias', 37 'high risk ' and 12 'low risk'. Twenty-two studies provided no usable or retrievable data i.e. none of our outcomes were addressed, no separate data reported for rosacea or limited data in abstracts.Eleven studies assessed our primary outcome 'change in quality of life', 52 studies participant-assessed changes in rosacea severity and almost all studies addressed adverse events, although often only limited data were provided. In most comparisons there were no statistically significant differences in number of adverse events, most were mild and transient. Physician assessments including investigators' global assessments, lesion counts and erythema were evaluated in three-quarters of the studies, but time needed for improvement and duration of remission were incompletely or not reported.The quality of the body of evidence was rated moderate to high for most outcomes, but for some outcomes low to very low.Data for several outcomes could only be pooled for topical metronidazole and azelaic acid. Both were shown to be more effective than placebo in papulopustular rosacea (moderate quality evidence for metronidazole and high for azelaic acid). Pooled data from physician assessments in three trials demonstrated that metronidazole was more effective compared to placebo (risk ratio (RR) 1.98, 95% confidence interval (CI) 1.29 to 3.02). Four trials provided data on participants' assessments, illustrating that azelaic acid was more effective than placebo (RR 1.46, 95% CI 1.30 to 1.63). The results from three studies were contradictory on which of these two treatments was most effective.Two studies showed a statistically significant and clinically important improvement in favour of topical ivermectin when compared to placebo (high quality evidence). Participants' assessments in these studies showed a RR of 1.78 (95% CI 1.50 to 2.11) and RR of 1.92 (95% CI 1.59 to 2.32),which were supported by physicians' assessments. Topical ivermectin appeared to be slightly more effective than topical metronidazole for papulopustular rosacea, based on one study, for improving quality of life and participant and physician assessed outcomes (high quality evidence for these outcomes).Topical brimonidine in two studies was more effective than vehicle in reducing erythema in rosacea at all time points over 12 hours (high quality evidence). At three hours the participants' assessments had a RR of 2.21 (95% CI 1.52 to 3.22) and RR of 2.00 (95% CI 1.33 to 3.01) in favour of brimonidine. Physicians' assessments confirmed these data. There was no rebound or worsening of erythema after treatment cessation.Topical clindamycin phosphate combined with tretinoin was not considered to be effective compared to placebo (moderate quality evidence).Topical ciclosporin ophthalmic emulsion demonstrated effectiveness and improved quality of life for people with ocular rosacea (low quality evidence).Of the comparisons assessing oral treatments for papulopustular rosacea there was moderate quality evidence that tetracycline was effective but this was based on two old studies of short duration. Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99) (high quality evidence). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doxycycline, but there was evidence of fewer adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54) (low quality evidence). There was very low quality evidence from one study (assessed at high risk of bias) that doxycycline 100 mg was as effective as azithromycin. Low dose minocycline (45 mg) was effective for papulopustular rosacea (low quality evidence).Oral tetracycline was compared with topical metronidazole in four studies and showed no statistically significant difference between the two treatments for any outcome (low to moderate quality evidence).Low dose isotretinoin was considered by both the participants (RR 1.23, 95% CI 1.05 to 1.43) and physicians (RR 1.18, 95% CI 1.03 to 1.36) to be slightly more effective than doxycycline 50-100 mg (high quality evidence).Pulsed dye laser was more effective than yttrium-aluminium-garnet (Nd:YAG) laser based on one study, and it appeared to be as effective as intense pulsed light therapy (both low quality evidence).

AUTHORS' CONCLUSIONS

There was high quality evidence to support the effectiveness of topical azelaic acid, topical ivermectin, brimonidine, doxycycline and isotretinoin for rosacea. Moderate quality evidence was available for topical metronidazole and oral tetracycline. There was low quality evidence for low dose minocycline, laser and intense pulsed light therapy and ciclosporin ophthalmic emulsion for ocular rosacea. Time needed to response and response duration should be addressed more completely, with more rigorous reporting of adverse events. Further studies on treatment of ocular rosacea are warranted.