Antibacterial therapy for acne: a guide to selection and use of systemic agents

Truncal Acne and Scarring: A Comprehensive Review of Current Medical and Cosmetic Approaches to Treatment and Patient Management

Acne vulgaris is one of the most common skin disorders worldwide. It typically affects skin areas with a high density of sebaceous glands such as the face, upper arms, chest, and/or back. Historically, the majority of research efforts have focused on facial acne vulgaris, even though approximately half of patients with facial lesions demonstrate truncal involvement. Truncal acne vulgaris is challenging to treat and poses a significant psychosocial burden on patients. Despite these characteristics, studies specifically examining truncal acne vulgaris are limited, with treatment guidelines largely derived from facial protocols. Therefore, truncal acne remains an understudied clinical problem. Here, we provide a clinically focused review on the epidemiology, evaluation, and available treatment options for truncal acne vulgaris. In doing so, we highlight knowledge gaps with the goal of spurring further investigation into the management of truncal acne vulgaris.

Electrostatically optimized adapalene-loaded emulsion for the treatment of acne vulgaris

Adapalene (AD) is an FDA-approved drug that shows good therapeutic efficacy for the treatment of acne vulgaris. However, due to its negative charge, AD cannot efficiently penetrate across the also negatively-charged skin membrane. This study is the first to assess the treatment of acne vulgaris using electrostatically optimized AD emulsions prepared using anionic AD with methoxy polyethylene glycol-b-poly(ε-caprolactone) (MC) as an anionic emulsifier coupled with a newly synthesized MC with different contents of an amine pendant-group (MC-[NH₂]_x) as a cationic emulsifier. The AD emulsion prepared using MC-[NH₂]_x with high cationic charge potential was significantly stable in the short-term studies compared with anionic MC or no emulsifier. Furthermore, the AD emulsion prepared with the cationic MC-[NH₂]_x emulsifier provided a two or three times stronger therapeutic effect against acne vulgaris than the AD emulsion prepared with the anionic MC emulsifier or no emulsifier in an animal study. Additionally, the AD emulsion with high cationic charge potential exerted a remarkable inhibition of macrophage expression, as confirmed by histological analysis. Therefore, the electrostatic interaction between the negatively-charged skin membrane and the AD emulsion prepared with the cationic MC-[NH₂]_x emulsifier provides a promising therapeutic strategy for acne vulgaris.

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Amphiphilic copolymer (MC) with different of amine contents (MC-[NH₂]x) was synthesized as a cationic emulsifier.

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AD emulsion prepared with MC-[NH₂]x provided an efficient therapeutic effect for the treatment of acne vulgaris.

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Electrostatically optimized adapalene (AD) emulsions prepared using MC-[NH₂]x for the treatment of acne vulgaris.

Tetracyclines and bone: Unclear actions with potentially lasting effects

Tetracyclines are a broad-spectrum class of antibiotics that have unclear actions with potentially lasting effects on bone metabolism. Initially isolated from Streptomyces, tetracycline proved to be an effective treatment for Gram +/- infections. The emergence of resistant bacterial strains commanded the development of later generation agents, including minocycline, doxycycline, tigecycline, sarecycline, omadacycline, and eravacycline. In 1957, it was realized that tetracyclines act as bone fluorochrome labels due to their high affinity for the bone mineral matrix. Over the course of the next decade, researchers discerned that these compounds are retained in the bone matrix at high levels after the termination of antibiotic therapy. Studies during this period provided evidence that tetracyclines could disrupt prenatal and early postnatal skeletal development. Currently, tetracyclines are most commonly prescribed as a long-term systemic therapy for the treatment of acne in healthy adolescents and young adults. Surprisingly, the impact of tetracyclines on physiologic bone modeling/remodeling is largely unknown. This article provides an overview of the pharmacology of tetracycline drugs, summarizes current knowledge about the impact of these agents on skeletal development and homeostasis, and reviews prior work targeting tetracyclines' effects on bone cell physiology. The need for future research to elucidate unclear effects of tetracyclines on the skeleton is addressed, including drug retention/release mechanisms from the bone matrix, signaling mechanisms at bone cells, the impact of newer third generation tetracycline antibiotics, and the role of the gut-bone axis.

Oral Antibiotics for Acne

Oral antibiotics are integral for treating inflammatory acne based on what is understood about the pathogenesis as well as the role of Cutibacterium acnes. However, rising concerns of antibiotic resistance and the perception of "antibiotic phobia" create potential limitations on their integration in an acne treatment regimen. When prescribing oral antibiotics, dermatologists need to consider dosage, duration, and frequency, and to avoid their use as monotherapy. These considerations are important, along with the use of newer strategies and compounds, to reduce adverse-event profiles, antibiotic resistance, and to optimize outcomes. Aside from concomitant medications, allergies, and disease severity, costs and patient demographics can influence variability in prescribing plans. There are multiple published guidelines and consensus statements for the USA and Europe to promote safe antibiotic use by dermatologists. However, there is a lack of head-to-head studies and evidence for comparative superiority of any individual antibiotic, as well as any evidence to support the use of agents other than tetracyclines. Although oral antibiotics are one of the main options for moderate to severe acne, non-antibiotic therapy such as isotretinoin and hormonal therapies should be considered. As newer therapies and more outcomes data emerge, so will improved management of antibiotic therapy to foster patient safety.

Sarecycline interferes with tRNA accommodation and tethers mRNA to the 70S ribosome

Sarecycline is the first narrow-spectrum tetracycline-class antibiotic that was recently approved by the FDA for the clinical treatment of acne vulgaris. In this work, we determined two (2.8-Å and 3.0-Å) X-ray crystal structures of sarecycline bound to the initiation complex of the bacterial 70S ribosome and found that this antibiotic inhibits bacterial ribosome in part using a mechanism of direct mRNA contact, which has not been reported for any other tetracyclines so far. Moreover, our structural analysis rationalizes why sarecycline is able to overcome one of the most common mechanisms of resistance to tetracyclines among pathogenic bacteria. Thus, this work provides mechanistic insights into the function of the tetracycline class of antibiotics on the ribosome with direct clinical relevance.

Sarecycline is a new narrow-spectrum tetracycline-class antibiotic approved for the treatment of acne vulgaris. Tetracyclines share a common four-ring naphthacene core and inhibit protein synthesis by interacting with the 70S bacterial ribosome. Sarecycline is distinguished chemically from other tetracyclines because it has a 7-[[methoxy(methyl)amino]methyl] group attached at the C7 position of ring D. To investigate the functional role of this C7 moiety, we determined the X-ray crystal structure of sarecycline bound to the Thermus thermophilus 70S ribosome. Our 2.8-Å resolution structure revealed that sarecycline binds at the canonical tetracycline binding site located in the decoding center of the small ribosomal subunit. Importantly, unlike other tetracyclines, the unique C7 extension of sarecycline extends into the messenger RNA (mRNA) channel to form a direct interaction with the A-site codon to possibly interfere with mRNA movement through the channel and/or disrupt A-site codon–anticodon interaction. Based on our biochemical studies, sarecycline appears to be a more potent initiation inhibitor compared to other tetracyclines, possibly due to drug interactions with the mRNA, thereby blocking accommodation of the first aminoacyl transfer RNA (tRNA) into the A site. Overall, our structural and biochemical findings rationalize the role of the unique C7 moiety of sarecycline in antibiotic action.

Rosa davurica Pall. Improves Propionibacterium acnes-Induced Inflammatory Responses in Mouse Ear Edema Model and Suppresses Pro-Inflammatory Chemokine Production via MAPK and NF-κB Pathways in HaCaT Cells

Acne, also known as acne vulgaris, is a common disorder of human skin involving the sebaceous gland and Propionibacterium acnes (P. acnes). Although there are a number of treatments suggested for acne, many of them have limitations in their safety and have efficacy issues. Therefore, there is a high demand to develop safe and effective novel acne treatments. In the present study, we demonstrate the protective effects of Rosa davurica Pall. leaves (RDL) extract against P. acnes-induced inflammatory responses in vitro and in vivo. The results showed that RDL dose-dependently inhibited the growth of skin bacteria, including P. acnes (KCTC3314) and aerobic Staphylococcus aureus (KCTC1621) or Staphylococcus epidermidis (KCTC1917). The downregulation of proinflammatory cytokines by RDL appears to be mediated by blocking the phosphorylations of mitogen-activated protein kinase (MAPK) and subsequent nuclear factor-kappa B (NF-κB) pathways in P. acnes-stimulated HaCaT cells. In a mouse model of acne vulgaris, histopathological changes were examined in the P. acnes-induced mouse ear edema. The concomitant intradermal injection of RDL resulted in the reduction of ear swelling in mice along with microabscess but exerted no cytotoxic effects for skin cells. Instrumental analysis demonstrated there were seven major components in the RDL extract, and they seemed to have important roles in the anti-inflammatory and antimicrobial effects of RDL. Conclusively, our present work showed for the first time that RDL has anti-inflammatory and antimicrobial effects against P. acnes, suggesting RDL as a promising novel strategy for the treatment of acne, including natural additives in anti-acne cosmetics or pharmaceutical products.

Sarecycline: a narrow spectrum tetracycline for the treatment of moderate-to-severe acne vulgaris

Sarecycline is a novel, narrow-spectrum, once-daily tetracycline-derived oral antibiotic that is FDA-approved in the US to be taken with or without food for moderate-to-severe acne vulgaris for ages 9 years of age and older. Sarecycline possesses anti-inflammatory properties and potent activity against Gram-positive bacteria, including activity against multiple strains of Cutibacterium acnes, while exhibiting minimal activity against enteric aerobic Gram-negative bacteria. Unlike many acne studies, sarecycline was investigated for chest and back acne. Significant reduction in inflammatory lesions was seen at week 12 at 1.5 mg/kg/day of sarecycline, with statistically significant improvement seen as early as week 3. No reports of phototoxicity, dizziness, pseudotumor cerebri or lupus but 1.2% nausea and 1.2% vaginal candidiasis was reported in the pivotal Phase III studies.

Potential Therapeutic Applications of Bee Venom on Skin Disease and Its Mechanisms: A Literature Review

Skin is larger than any other organ in humans. Like other organs, various bacterial, viral, and inflammatory diseases, as well as cancer, affect the skin. Skin diseases like acne, atopic dermatitis, and psoriasis often reduce the quality of life seriously. Therefore, effective treatment of skin disorders is important despite them not being life-threatening. Conventional medicines for skin diseases include corticosteroids and antimicrobial drugs, which are effective in treating many inflammatory and infectious skin diseases; however, there are growing concerns about the side effects of these therapies, especially during long-term use in relapsing or intractable diseases. Hence, many researchers are trying to develop alternative treatments, especially from natural sources, to resolve these limitations. Bee venom (BV) is an attractive candidate because many experimental and clinical reports show that BV exhibits anti-inflammatory, anti-apoptotic, anti-fibrotic, antibacterial, antiviral, antifungal, and anticancer effects. Here, we review the therapeutic applications of BV in skin diseases, including acne, alopecia, atopic dermatitis, melanoma, morphea, photoaging, psoriasis, wounds, wrinkles, and vitiligo. Moreover, we explore the therapeutic mechanisms of BV in the treatment of skin diseases and killing effects of BV on skin disease-causing pathogens, including bacteria, fungi and viruses.

Microbiological Profile of Sarecycline, a Novel Targeted Spectrum Tetracycline for the Treatment of Acne Vulgaris

Sarecycline is the first narrow-spectrum tetracycline-class antibiotic being developed for acne treatment. In addition to exhibiting activity against important skin/soft tissue pathogens, sarecycline exhibits targeted antibacterial activity against clinical isolates of Cutibacterium acnes.

Sarecycline is the first narrow-spectrum tetracycline-class antibiotic being developed for acne treatment. In addition to exhibiting activity against important skin/soft tissue pathogens, sarecycline exhibits targeted antibacterial activity against clinical isolates of Cutibacterium acnes. In the current study, sarecycline was 16- to 32-fold less active than broad-spectrum tetracyclines—such as minocycline and doxycycline—against aerobic Gram-negative bacilli associated with the normal human intestinal microbiome. Also, reduced activity against Escherichia coli was observed in vivo in a murine septicemia model, with the 50% protective doses, or the doses required to achieve 50% survival, being >40 mg/kg of body weight and 5.72 mg/kg for sarecycline and doxycycline, respectively. Sarecycline was also 4- to 8-fold less active than doxycycline against representative anaerobic bacteria that also comprise the normal human intestinal microbiome. Additionally, C. acnes strains displayed a low propensity for the development of resistance to sarecycline, with spontaneous mutation frequencies being 10⁻¹⁰ at 4 to 8 times the MIC, similar to those for minocycline and vancomycin. When tested against Gram-positive pathogens with defined tetracycline resistance mechanisms, sarecycline was more active than tetracycline against tet(K) and tet(M) strains, with MICs ranging from 0.125 to 1.0 μl/ml and 8 μl/ml, respectively, compared with MICs of 16 to 64 μl/ml and 64 μl/ml for tetracycline, respectively. However, sarecycline activity against the tet(K) and tet(M) strains was decreased compared to that against the wild type, which demonstrated MICs ranging from 0.06 to 0.25 μl/ml, though the decrease in the activity of sarecycline against the tet(K) and tet(M) strains was not as pronounced as that of tetracycline. These findings support sarecycline as a narrow-spectrum tetracycline-class antibiotic that is effective for the treatment of acne, and further investigation into the potential reduced effects on the gut microbiome compared with those of other agents is warranted.

Microbial Ecology of the Human Skin

This review article on the skin microbiota was written in response to recent advances that transitioned from culture methods to PCR amplification and sequencing of bacterial and fungal genes as a result of the Human Microbiome Project. This transition enables the investigation of the full diversity of microorganisms inhabiting human skin. The skin provides a range of habitats with different microbiota associated with the three major regions of the skin, namely the moist axilla, perineum, and toe webs; oily or sebaceous head, neck, and trunk; and dry forearms and legs. These new culture-independent tools are revealing the diversity of the human skin microbiota in the different locations of the body and with skin depth. These tools should lead to a better understanding of the state of homeostasis between the microbiota and the host and the overall functionality of that microbiota.

Oral Antibacterial Therapy for Acne Vulgaris: An Evidence-Based Review

BACKGROUND

To some degree, acne vulgaris affects nearly every individual worldwide. Oral antibiotic therapy is routinely prescribed for the treatment of moderate to severe inflammatory acne; however, long-term use of oral antibiotics for acne may have unintended consequences.

OBJECTIVE

The aim of this study was to provide a systematic evaluation of the scientific evidence on the efficacy and appropriate use of oral antibiotics in the treatment of acne.

METHODS

A systematic search of MEDLINE was conducted to identify randomized controlled clinical trials, systematic reviews, and meta-analyses evaluating the efficacy of oral antibiotics for acne. Overall, 41 articles that examined oral antibiotics compared with placebo, another oral therapy, topical therapy, alternate dose, or duration were included in this study.

RESULTS

Tetracyclines, macrolides, and trimethoprim/sulfamethoxazole are effective and safe in the treatment of moderate to severe inflammatory acne. Superior efficacy of one type or class of antibiotic could not be determined, therefore the choice of antibiotic is generally based on the side-effect profile. Although different dosing regimens have been studied, there is a lack of standardized comparator trials to determine optimal dosing and duration of each oral antibiotic used in acne. The combination of oral antibiotics with a topical therapy is superior to oral antibiotics alone.

CONCLUSION

This article provides a systematic evaluation of the scientific evidence of the efficacy of oral antibiotics for acne. Due to heterogeneity in the design of the trials, there is insufficient evidence to support one type, dose, or duration of oral antibiotic over another in terms of efficacy; however, due to increasing resistance to antibiotics, dermatologists should heed consensus guidelines for their appropriate use.

Meeting the Challenges of Acne Treatment in Asian Patients: A Review of the Role of Dermocosmetics as Adjunctive Therapy

Conventional acne treatment presents several challenges such as intolerable side effects and antibiotic resistance. Dermocosmetic products may be used to reduce these unwanted effects. Dermocosmetics include skin cleansers, topical sebum-controllers, skin antimicrobial/anti-inflammatory agents, moisturizers, sunscreens, and camouflage products. Appropriate use of these products may help augment the benefit of acne treatment, minimize side effects, and reduce the need for topical antibiotics. In Asia, there is currently limited scientific data on the application and recommendations for dermocosmetic use in acne vulgaris (AV). This article reviews the evidence on dermocosmetics for AV and provides practice recommendations as discussed during the 4^th Asia-Pacific Acne Leaders' Summit held in Bangkok, Thailand, on 7 and 8 February 2015. Through a premeeting survey, a series of plenary lectures, a stepwise program of discussion sessions, and Medline article review, the Expert Panel set forth relevant recommendations on the role of dermocosmetics as adjunct for treating AV in Asian patients.

Minocycline-Induced Cutaneous Hyperpigmentation in an Orthopedic Patient Population

Background. The objectives of this study were to estimate the incidence and evaluate risk factors for development of minocycline-induced cutaneous hyperpigmentation in patients with orthopedic infections.

Methods. Patients with orthopedic infections evaluated at Mayo Clinic (Rochester, MN) and treated with minocycline from 1 January 2002 to 31 December 2011 were retrospectively identified. Long-term minocycline suppression was defined as daily minocycline use for at least 3 months. A proportional hazards model was used to evaluate potential risk factors.

Results. Of 291 patients receiving long-term minocycline suppression, 54% (156 of 291) developed hyperpigmentation after a mean follow-up of 4.8 years (range, 0.3–13.2 years); 88% involved blue-gray pigmentation of normal skin that appeared most commonly in the lower (75%) and upper extremities (44%). The mean duration of minocycline therapy before hyperpigmentation was 1.5 years (range, 0.1–9 years) with a mean cumulative dosage of 107.3 g (range, 8.6–657 g). Notable risk factors include a history of vitamin D deficiency (relative risk [RR], 6.29; 95% confidence interval [CI], 1.91–15.27; P = .0052), presence of a shoulder prosthesis (RR, 3.2; 95% CI, 1.23–6.56; P = .0062), noncirrhotic liver pathology (RR, 3.63; 95% CI, 1.11–8.75; P = .0359), and use of a concurrent medication also known to cause hyperpigmentation (RR, 4.75; 95% CI, 1.83–10.1; P = .0029).

Conclusions. Hyperpigmentation associated with the use of long-term minocycline suppression in patients with orthopedic infections is common.

Safety Considerations and Monitoring in Patients Treated with Systemic Medications for Acne

Acne vulgaris, a disorder of the pilosebaceous unit, is one of the most commonly encountered conditions in dermatology practice. Effective treatment of acne vulgaris is important in that it can prevent psychosocial distress and physical scarring. Systemic therapeutic options are available for moderate to severe acne. It is imperative that the safe and effective treatment revolves around the health care provider's familiarity of side effects of various treatments. In this article, the side effects and monitoring guide for the most commonly prescribed systemic agents for acne vulgaris are reviewed.

Adverse effects of acne medications: recognition and management

Acne vulgaris is a very common chronic inflammatory disease of the skin. The clinical features of acne range from non-inflammatory comedones to inflammatory nodules. While often perceived as an adolescent disease, the prevalence remains high into adulthood, and the manifestations can have detrimental psychosocial effects. It is therefore not surprising that many patients are motivated to seek treatment. The existing treatment strategies for acne are complex due to the multifactorial pathogenesis of the disease. Although it is difficult to cure, four categories of medications have proved efficacious in reducing acne lesions: topical agents, systemic antibiotics, systemic retinoids, and hormonal agents. Unfortunately, these medications can cause adverse effects that may limit their use. Typically, these adverse effects are mild and transient and can be remedied by altering the dose or frequency of the offending agent. However, more serious adverse effects can occur that pose a significant health risk to the patient. Understanding how to recognize and manage the adverse effects of common acne therapies is imperative to providing the safest and most appropriate treatment for each patient. This article focuses on the recognition and management of adverse effects associated with current acne medications.

Microbial ecology of the skin in the era of metagenomics and molecular microbiology

The skin is the primary physical barrier between the body and the external environment and is also a substrate for the colonization of numerous microbes. Previously, dermatological microbiology research was dominated by culture-based techniques, but significant advances in genomic technologies have enabled the development of less-biased, culture-independent approaches to characterize skin microbial communities. These molecular microbiology approaches illustrate the great diversity of microbiota colonizing the skin and highlight unique features such as site specificity, temporal dynamics, and interpersonal variation. Disruptions in skin commensal microbiota are associated with the progression of many dermatological diseases. A greater understanding of how skin microbes interact with each other and with their host, and how we can therapeutically manipulate those interactions, will provide powerful tools for treating and preventing dermatological disease.

Evidence-based recommendations for the diagnosis and treatment of pediatric acne

INTRODUCTION

Acne vulgaris is one of the most common skin conditions in children and adolescents. The presentation, differential diagnosis, and association of acne with systemic pathology differs by age of presentation. Current acknowledged guidelines for the diagnosis and management of pediatric acne are lacking, and there are variations in management across the spectrum of primary and specialty care. The American Acne and Rosacea Society convened a panel of pediatric dermatologists, pediatricians, and dermatologists with expertise in acne to develop recommendations for the management of pediatric acne and evidence-based treatment algorithms.

METHODS

Ten major topic areas in the diagnosis and treatment of pediatric acne were identified. A thorough literature search was performed and articles identified, reviewed, and assessed for evidence grading. Each topic area was assigned to 2 expert reviewers who developed and presented summaries and recommendations for critique and editing. Furthermore, the Strength of Recommendation Taxonomy, including ratings for the strength of recommendation for a body of evidence, was used throughout for the consensus recommendations for the evaluation and management of pediatric acne. Practical evidence-based treatment algorithms also were developed.

RESULTS

Recommendations were put forth regarding the classification, diagnosis, evaluation, and management of pediatric acne, based on age and pubertal status. Treatment considerations include the use of over-the-counter products, topical benzoyl peroxide, topical retinoids, topical antibiotics, oral antibiotics, hormonal therapy, and isotretinoin. Simplified treatment algorithms and recommendations are presented in detail for adolescent, preadolescent, infantile, and neonatal acne. Other considerations, including psychosocial effects of acne, adherence to treatment regimens, and the role of diet and acne, also are discussed.

CONCLUSIONS

These expert recommendations by the American Acne and Rosacea Society as reviewed and endorsed by the American Academy of Pediatrics constitute the first detailed, evidence-based clinical guidelines for the management of pediatric acne including issues of special concern when treating pediatric patients.

In vitro antibiotic susceptibility patterns of Propionibacterium acnes isolated from acne patients: an Egyptian university hospital-based study

BACKGROUND

Antibiotics have been used for more than 40 years against Propionibacterium acnes (P. acnes), the most common agent of acne. Antibiotic resistance to this bacterium becomes a worldwide problem in recent years. No studies are available on antibiotic susceptibility patterns of P. acnes among Egyptian acne patients.

OBJECTIVE

To determine antibiotic susceptibility patterns of P. acnes isolated from acne patients attending the Dermatology outpatient clinic of an Egyptian university hospital to the most commonly prescribed antibiotics and to determine the difference in relation to age of patients, disease duration and previous antibiotic therapy for acne.

METHODS

Cutaneous samples were obtained from pustular acne lesions on the face of 115 patients, which were cultured in anaerobic media to demonstrate the presence of P. acnes. Antibiotic susceptibility tests of isolated P. acnes were then performed to clindamycin, erythromycin, azithromycin, oxytetracycline and doxycycline by disk diffusion method.

RESULTS

Propionibacterium acnes was isolated from 98 patients. Eighty-nine isolates were susceptible to azithromycin, followed by doxycycline and oxytetracycline isolated from 82 and 72 patients respectively. Resistance of P. acnes to clindamycin was detected in 65 patients, followed by erythromycin in 48 patients. Comparing the antibiotic susceptibility patterns of P. acnes isolated from patients with and without previous antibiotic therapy for acne revealed statistically non-significant differences as regards any of the antibiotics tested except for clindamycin and erythromycin. Statistically non-significant differences existed between antibiotic susceptibility patterns of P. acnes to all tested antibiotics regarding age of patients (< or ≥ 20 years) and disease duration (< or ≥ 2 years).

CONCLUSION

Propionibacterium acnes in vitro susceptibility patterns differed among Egyptian patients to the commonly prescribed antibiotics with the highest to lowest resistance to clindamycin, erythromycin, oxytetracycline, doxycycline and azithromycin.

Staphylococcus aureus in Acne Pathogenesis: A Case-Control Study

BACKGROUND

There is considerable evidence which suggests a possible pathogenetic role for Staphylococcus aureus (S. aureus) in acne vulgaris.

AIM

The study was to determine S. aureus colonization and antibiotic susceptibility patterns in patients with acne and of healthy people.

MATERIALS AND METHODS

In the case-control study, a total of 324 people were screened for nasal carriage of S. aureus: 166 acne patients and 158 healthy persons. One control subject was individually matched to one case. Nasal swabs from anterior nares of individuals were cultured and identified as S. aureus. Antibiotic sensitivity was performed with recognized laboratory techniques.

RESULTS

S. aureus was detected in 21.7% of the subjects in acne, and in 26.6% of control groups. There was no statistical difference in colonization rates between two groups (P=0.3). In patient group, most of S. aureus isolates were resistant to doxicycline and tetracycline (P=0.001), and were more sensitive to rifampicin compared to other drugs. In control samples, the isolated demonstrated higher resistance to cotrimoxazole compared to patient samples (P=0.0001). There was no difference between groups regarding resistance to rifampicin, vancomycin, methicillin, and oxacillin.

CONCLUSION

It is still unclear whether S. aureus is actually a causal agent in the pathogenesis of acne. Based on microbiological data of both healthy and acne-affected persons, we propose that contribution of S. aureus in acne pathogenesis is controversial.

Therapeutic considerations for severe nodular acne

Severe nodular acne, defined as grade 4 or 5 acne on the Investigator's Static Global Assessment scale, is a skin condition characterized by intense erythema, inflammation, nodules, cysts, and scarring. Both the well known risk of physical scarring and the more recent recognition that acne can be a chronic, psychologically distressing disease with significant adverse effects on a patient's quality of life, have prompted earlier, more aggressive treatment with more effective medications, in the hope of preventing progression to more severe, nodular forms of the disease. Oral antibacterials, primarily tetracyclines, have long been the first-line therapy for severe nodular acne, which frequently remained refractory to therapy. However, concerns of antibacterial adverse effects, patient adherence, and antimicrobial resistance prompted the search for alternate therapies and combinations thereof in order to target the multifactorial pathogenesis of the disease. Isotretinoin, an oral retinoid introduced in 1982, has since become the gold standard therapy in severe acne and has revolutionized its treatment. Several adjunctive agents exist. Oral antibacterials are indicated as an alternative for patients with severe acne who cannot tolerate oral retinoids, or for whom a contraindication exists. In order to prevent bacterial resistance, antibacterials should always be used in combination with benzoyl peroxide, a nonantibiotic antimicrobial agent with anti-inflammatory activity. Topical retinoids are often added to this regimen. In women, hormonal agents, which include oral contraceptives, spironolactone, and oral corticosteroids, and, in Europe, cyproterone acetate, may be used as monotherapy or concomitantly with isotretinoin. For rapid treatment of inflammatory nodules, intralesional corticosteroids are effective. These treatment modalities have been studied, refined, and combined in novel ways in order to target the multifactorial pathogenesis of the disease, and in this article we review each of their roles.

Antibiotic susceptibility of Propionibacterium acnes isolated from acne vulgaris in Korea

Propionibacterium acnes plays an important role in the development of acne, and inflammatory lesions are improved by antibiotics. Long-term use of antibiotics may result in development of resistant strains and treatment failure. The aim of the present study was to investigate the isolation rate of P. acnes and to evaluate its antibiotic susceptibility to widely used antibiotics in acne in Korea. Among 46 patients, 31 P. acnes strains were cultured. Isolated P. acnes was measured for minimum inhibitory concentration (MIC) of tetracycline, doxycycline, minocycline, erythromycin and clindamycin using an Epsilometer test. Age, disease duration and previous history of antibiotic therapy for acne were compared in relation to the MIC. The mean MIC of tetracycline, minocyclines, doxycycline, clindamycin and erythromycin were all below the breakpoint of antibiotic resistance. The patients with acne vulgaris with disease duration of more than 2 years documented higher MIC values in doxycycline, erythromycin, and clindamycin than those of less than 2 years. The patients who were previously treated with topical or systemic antibiotics showed higher MIC in doxycycline. Antibiotic resistance of P. acnes is still low in Korea, but at this point, there is an increasing trend of MIC. Caution and acknowledgement of increased risk of antibiotic resistant P. acnes should be advised in acne antibiotic treatment to minimize and avoid the emergence of the resistant strain.

The role of tetracyclines in rosacea

There is a great deal of evidence to support the use of tetracycline and doxycycline in the treatment of papulopustular rosacea. Nevertheless, these agents have shared and unique adverse effects and relative contraindications. Recently, subantimicrobial-dose doxycycline was demonstrated to be an effective treatment for rosacea, due to its inherent anti-inflammatory properties. Furthermore, subantimicrobial-dose doxycycline has a more preferable tolerability profile and a lower occurrence of bacterial resistance than traditional-dose doxycycline. To further elucidate the role of tetracycline agents in rosacea, clinical trials that compare these agents with each other as well as with other effective rosacea treatments are called for. Adherence studies comparing oral tetracycline treatment with topical metronidazole treatment may also enhance clinical decision making.

Treatment of acne vulgaris: a literature review / Lečenje običnih akni (acne vulgaris) – pregled literature

Acne vulgaris is a common skin disease, which affects individuals of all races and ages. In Caucasians, almost 85% of individuals between 12 and 25 years, as well as 25% of adults, are affected with some forms of acne. The pathophysiology of acne is multifactorial, and thus, the treatment must cover all the possible causes of acne. For this reason, acne therapy is mostly a combination therapy, with the main goal to achieve clinical improvement, without scarring and residuals, as much as possible. The treatment should be planned individually, depending on the clinical appearance, severity and psychological profile of the patient. The treatment usually takes time and requires dedication and patience of both the patient and the physician.

The efficacy and safety of amoxicillin, trimethoprim-sulfamethoxazole, and spironolactone for treatment-resistant acne vulgaris

In situations where acne has proved resistant to other systemic agents or they are not indicated and isotretinoin is not desired by patients, the authors find amoxicillin, TMP-SMX, and spironolactone, alone or in combination, useful alternatives. In women who have acne, spironolactone can be used, and in patients who have sulfa allergy, amoxicillin can be used. It is important to continue alternate topical therapy along with these interventions to augment the improvement and to assist in the eventual discontinuance of oral medication. All of the authors' patients were using topical therapy concomitantly and, although this may have contributed to improvement, the authors believe the addition of amoxicillin, TMP-SMX, or spironolactone contributes to the majority of improvement. Tetrospective chart analysis provides supportive data for amoxicillin, TMP-SMX, and spironolactone in the treatment of refractory acne vulgaris.

Is osteoarthritis an infection-associated disease and a target for chemotherapy?

The treatment of osteoarthritis (OA) continues to be a challenge, and current treatment modalities are disappointing. New approaches in therapy may be developed as a result of evidence of the involvement of inflammatory cytokines in the progression of OA. Cotrimoxazole (sulfamethoxazole/trimethoprim) was noted to have anti-inflammatory properties and has been used in the therapy of several autoimmune diseases. Analyzing our own and world experience, we propose that OA and degenerative joint and spine disease might be infection-associated diseases and a target for sulfamethoxazole/trimethoprim therapy.

Emerging chemotherapeutic strategies for Huntington's disease

Huntington's disease (HD) is a progressive and fatal neurological disorder caused by an expanded CAG repeat in the gene coding for the protein, huntingtin. There is no clinically proven treatment for HD. Although the exact cause of neuronal death in HD remains unknown, it has been postulated that the abnormal aggregation of the mutant huntingtin protein may cause toxic effects in neurons, leading to a cascade of pathogenic mechanisms associated with transcriptional dysfunction, oxidative stress, mitochondrial alterations, apoptosis, bioenergetic defects and subsequent excitotoxicity. Understanding how these processes interrelate has become important in identifying a pharmacotherapy in HD and in the design of clinical trials. A number of drug compounds that separately target these mechanisms have significantly improved the clinical and neuropathological phenotype of HD transgenic mice and, as such, are immediate candidates for human clinical trials in HD patients. These compounds are discussed herein.

Acne vulgaris: a review of antibiotic therapy

Antibiotic therapy has been integral to the management of inflammatory acne vulgaris for many years. Systemic antibiotics work via antibacterial, anti-inflammatory and immunomodulatory modes of action, and have been found to be useful in managing moderate-to-severe acne. Commonly prescribed antibiotics include tetracyclines, erythromycin and trimethoprim, with or without sulfamethoxazole. In selecting the appropriate antibiotic for patients needing to receive topical or systemic antibiotic therapy, the clinician should take into account the severity of the acne, cost-effectiveness, the safety profile of the drug and the potential for development of resistance. The widespread and long-term use of antibiotics over the years has unfortunately led to the emergence of resistant bacteria. The global increase in the antibiotic resistance of Propionibacterium acnes may be a significant contributing factor in treatment failures. It is therefore essential that clinicians prescribing antibiotics for the treatment of acne adopt strategies to minimise further development of bacterial resistance. This includes addressing compliance issues, using combination therapies, avoiding prolonged antibiotic treatment, and avoiding concomitant topical and oral antibiotics with chemically dissimilar antibiotics.

Conjoint analysis: a novel, rigorous tool for determining patient preferences for topical antibiotic treatment for acne. A randomised controlled trial

BACKGROUND

Acne vulgaris is an extremely common skin disorder that can be treated effectively with drugs that are currently available. Poor compliance, however, is a major factor in the high failure rates seen in acne treatment. Compliance might be enhanced by considering patient preferences for acne medications. Conjoint analysis is well suited for the study of patient preferences in healthcare, but is novel to the field of dermatology.

OBJECTIVES

The study aimed to determine and compare patient preferences for four topical antibiotics used for 1 week, once or twice daily, to treat acne vulgaris.

METHODS

A randomised, phase IV, single-centre, cross-over study was performed using conjoint analysis and a traditional patient questionnaire. Over 4 weeks, the patients used each of four topical antibiotics for 1 week: erythromycin/zinc solution, clindamycin phosphate lotion, benzoyl peroxide (BP)/erythromycin gel (each applied twice daily) and clindamycin phosphate gel (applied once daily). The conjoint analysis examined five different attributes of acne medications: form, storage, product life once opened, method of application and regimen (each with two or three possible options). From 108 possible permutations of the five attributes, 16 hypothetical medications were selected at random and described on printed cards. Pre- and post-treatment, the patients ranked the cards in order of preference and rated each hypothetical product based on their likelihood to use it. For each patient, product 'utilities' were then calculated by multiple regression. The patients also completed a patient acceptability questionnaire, by which they rated the product acceptability after 1 week of treatment with each of the four topical antibiotics. The patients later ranked the medications in order of preference after using all four treatments. Adverse events were recorded in diary cards to assess tolerability.

RESULTS

Of 67 patients recruited, 64 used all four medications and completed the study. The conjoint analysis found that a gel formulation, room temperature storage, product life of up to 18 months once opened, application with fingers and once-daily regimen were the options ranked first for the five product attributes. According to the ranking order (out of 108) for the combination of attributes representing the four study medications, clindamycin phosphate gel had the highest rankings (6 and 1 pre- and post-treatment, respectively) and BP/erythromycin gel had the lowest rankings (93 and 70 pre- and post-treatment). The rankings of clindamycin phosphate lotion and erythromycin/zinc solution worsened from pre- to post-treatment, indicating a shift in patient preference after they experienced products 'in-use' during the study. Based on the questionnaire, clindamycin phosphate gel was liked best by the highest proportion of patients (33%). In terms of overall satisfaction, the order of preference was: (i) clindamycin phosphate gel, (ii) clindamycin phosphate lotion, (iii) BP/erythromycin gel and (iv) erythromycin/zinc solution. Adverse events related to medication occurred most frequently with erythromycin/zinc solution and BP/erythromycin gel. Clindamycin phosphate gel was the only product not associated with any episodes resulting in a change of medication or dose.

CONCLUSIONS

Conjoint analysis provided a convenient, reliable tool for assessing patient preferences for topical antibiotics used to treat acne. The patients clearly preferred a gel formulation that could be applied with the fingers once daily and stored at room temperature for as long as 18 months. One product (clindamycin phosphate gel) combined all five of the preferred attributes, a preference confirmed by the simulated product rankings. These findings of the conjoint analysis are consistent with the safety profiles and the results of the traditional questionnaire.

Comparative in vitro activities of retapamulin (SB-275833) against 141 clinical isolates of Propionibacterium spp., including 117 P. acnes isolates

Using the NCCLS agar dilution method, we studied the in vitro activity of retapamulin (SB-275833) against 141 clinical isolates of Propionibacterium species, including seven multiresistant strains, and found retapamulin to be the most active agent among those tested with MICs of < or = 1 microg/ml against all isolates.

Acne: Systemic treatment

Acne vulgaris is a disease affecting mostly adolescents and young adults that, when severe, has the potential to result in scarring and permanent disfigurement. Systemic treatment is necessary to prevent significant psychological and social impairment in these patients.(1) Significant inflammatory and nodulocystic acne is usually recalcitrant to topical treatment, whereas uncommon acne variants, such as acne fulminans, pyoderma faciale, and acne conglobata, need to be promptly and effectively controlled. In all of these circumstances, systemic agents are indispensable. The choices include oral antibiotics, isotretinoin, and hormonal treatment (Table 1).

Topical antibacterial treatments for acne vulgaris : comparative review and guide to selection

Topical antibacterial agents are an essential part of the armamentarium for treating acne vulgaris. They are indicated for mild-to-moderate acne, and are a useful alternative for patients who cannot take systemic antibacterials. Topical antibacterials such as clindamycin, erythromycin, and tetracycline are bacteriostatic for Propionibacterium acnes, and have also been demonstrated to have anti-inflammatory activities through inhibition of lipase production by P. acnes, as well as inhibition of leukocyte chemotaxis. Benzoyl peroxide is a non-antibiotic antibacterial agent that is bactericidal against P. acnes and has the distinct advantage that thus far, no resistance has been detected against it. Combined agents such as erythromycin/zinc, erythromycin/tretinoin, erythromycin/isotretinoin, erythromycin/benzoyl peroxide, and clindamycin/benzoyl peroxide are increasingly being used and have been proven to be effective. They generally demonstrate good overall tolerability and are useful in reducing the development of antibacterial resistance in P. acnes. The selection of a topical antibacterial agent should be tailored for specific patients by choosing an agent that matches the patient's skin characteristics and acne type. Topical antibacterial agents should generally not be used for extended periods beyond 3 months, and topical antibacterials should ideally not be combined with systemic antibacterial therapy for acne; in particular, the use of topical and systemic antibacterials is to be avoided as far as possible.

In vitro antibacterial and anti-inflammatory effects of honokiol and magnolol against Propionibacterium sp

Honokiol and magnolol, two major phenolic constituents of Magnolia sp., have been known to exhibit antibacterial activities. However, until now, their antibacterial activity against Propionibacterium sp. has not been reported. To this end, the antibacterial activities of honokiol and magnolol were detected using the disk diffusion method and a two-fold serial dilution assay. Honokiol and magnolol showed strong antibacterial activities against both Propionibacterium acnes and Propionibacterium granulosum, which are acne-causing bacteria. The minimum inhibitory concentrations (MIC) of honokiol and magnolol was 3-4 microg/ml (11.3-15 microM) and 9 microg/ml (33.8 microM), respectively. In addition, the killing curve analysis showed that magnolol and honokiol killed P. acnes rapidly, with 10(5) organisms/ml eliminated within 10 min of treatment with either 45 microg (169.2 microM) of magnolol or 20 microg (75.2 microM) of honokiol per ml. The cytotoxic effect of honokiol and magnolol was determined by a colorimetric (3-(4,5-dimetyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) (MTT) assay using two animal cell lines, human normal fibroblasts and HaCaT. In this experiment, magnolol exhibited lower cytotoxic effects than honokiol at the same concentration, but they showed similar cytotoxicity when triclosan was employed as an acne-mitigating agent. In addition, they reduced secretion of interleukin-8 and tumor necrosis factor alpha (TNF-alpha) induced by P. acnes in THP-1 cells indicating the anti-inflammatory effects of them. When applied topically, neither phenolic compound induced any adverse reactions in a human skin primary irritation test. Therefore, based on these results, we suggest the possibility that magnolol and honokiol may be considered as attractive acne-mitigating candidates for topical application.