Antibiotic resistant propionibacteria in acne: need for policies to modify antibiotic usage

Antibiotic resistance in dermatology: The scope of the problem and strategies to address it

Antibiotic resistance is a growing health concern that has attracted increasing attention from clinicians and scientists in recent years. Although resistance is an inevitable consequence of bacterial evolution and natural selection, misuse and overuse of antibiotics play a significant role in its acceleration. Antibiotics are the mainstay of therapy for common dermatoses, including acne and rosacea, as well as for skin and soft tissue infections. Therefore, it is critical for dermatologists and physicians across all disciplines to identify, appropriately manage, and prevent cases of antibiotic resistance. This review explores dermatologic conditions in which the development of antibiotic resistance is a risk and discusses mechanisms underlying the development of resistance. We discuss disease-specific strategies for overcoming resistant strains and improving antimicrobial stewardship along with recent advances in the development of novel approaches to counter antibiotic resistance.

Antibiotic resistance in acne: changes, consequences and concerns

Antibiotic resistance in acne was first observed in the 1970s and has been a major concern in dermatology since the 1980s. The resistance rates and types of antimicrobials have subsequently shown great variations in regions and countries. Illustrative of this is the resistance to topical erythromycin and clindamycin which continues to be a problem worldwide, while resistance to systemic treatment with tetracyclines has remained low during the past decade. The resistance for the newer macrolides like azithromycin and clarithromycin has been increasing. The results of antibiotic resistance may include treatment failure of acne, disturbance of skin microbiota, induction of opportunistic pathogens locally and systemically, and dissemination of resistant strains to both healthcare personnel and the general population. The ensuing complications, such as aggravated opportunistic infections caused by Propionibacterium acnes and the emergence of multiresistant superbugs, have not yet been confirmed.

Pulsed 450 nm blue light significantly inactivates Propionibacterium acnes more than continuous wave blue light

Infection with Propionibacterium acnes is ubiquitous, and drug resistant strains have been on the rise as the use of pharmaceutical antimicrobials continues to engender the emergence of further resistant strains. In previous studies, we showed that treatment with blue light serves as an alternative to pharmaceutical intervention. As a part of our ongoing effort to improve the antimicrobial efficacy of blue light, we studied the effect of pulsed 450 nm light on P. acnes in vitro and compared two pulsed rates with continuous wave irradiation. We irradiated cultures of P. acnes at various irradiances and radiant energies either singly or repeatedly at various time intervals, using printed micro-LEDs, with the goal of finding the lowest combination of irradiance and radiant energy that would yield 100% bacterial suppression. Our results show that treatment with 33% pulsed light gave the best result compared to 20% pulsed wave or continuous wave. Timing irradiation to coincide with the replication cycle of P. acnes produced a significantly better antimicrobial effect. Furthermore, repeated irradiation at 3-h or 4-h interval enabled significant bacterial suppression even at lower irradiances; thus, making single irradiation at high irradiances unnecessary. Moreover, combining repeated irradiation with appropriate duration of treatment and 33% irradiation pulse rate gave optimal 100% [7 log₁₀] bacterial suppression.

Pulsed 450 nm blue light suppresses MRSA and Propionibacterium acnes in planktonic cultures and bacterial biofilms

In our recent study, we showed that pulsed blue light (PBL) suppresses the growth of Propionibacterium acnes more than continuous wave (CW) blue light in vitro, but it is not known that other bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), respond similarly to PBL. The high potency of PBL relative to CW blue light makes it a suitable antimicrobial for suppressing bacterial growth in biofilms as well. Therefore, we determined if MRSA-a deadly bacterium of global concern-is susceptible to 450 nm PBL irradiation in vitro, and ascertained whether the bactericidal effect of PBL on planktonic P. acnes culture can be replicated in biofilms of P. acnes and MRSA. In three series of experiments, we irradiated P. acnes and MRSA respectively, either in planktonic cultures, forming biofilms or formed biofilms. Compared to controls, the results showed 100% bacterial suppression in planktonic cultures of MRSA irradiated with 3 mW/cm² irradiance and 7.6 J/cm² radiant exposure three times at 30-minute intervals, and also in P. acnes cultures irradiated with 2 mW/cm² irradiance 5 J/cm² radiant exposure thrice daily during each of 3 days. Irradiation of biofilms with the same irradiances and radiant exposures that gave 100% bacterial suppression in planktonic cultures resulted in disruption and disassembly of the architecture of MRSA and P. acnes biofilms, more so in forming biofilms than formed biofilms. The antimicrobial effect on each bacterium was minimal in forming biofilms, and even less in formed biofilms. Increasing radiant exposure slightly from 7.6 J/cm² to 10.8 J/cm² without changing any other parameter, yielded more disruption of the biofilm and fewer live MRSA and P. acnes, suggesting that 100% bacterial suppression is possible with further refinement of the protocol. In both planktonic cultures and biofilms, PBL suppressed MRSA more than P. acnes.

Microbial biofilms and the human skin microbiome

The human skin microbiome plays an important role in both health and disease. Microbial biofilms are a well-characterized mode of surface-associated growth, which present community-like behaviors. Additionally, biofilms are a critical element in certain skin diseases. We review how the perception of the resident skin microbiota has evolved from the early linkages of certain microbes to disease states, to a more comprehensive and intricate understanding brought on by biofilm and microbiome revelations. Rapidly expanding arsenals of experimental methods are opening new horizons in the study of human-microbe and microbe-microbe interactions. Microbial community profiling has largely remained a separate discipline from that of biofilm research, yet the introduction of metatranscriptomics, metabolomics, and the ability to distinguish between dormant and active members of a community have all paved the road toward a convergent cognizance of the encounter between these two microbial disciplines.

Systematic review of antibiotic resistance in acne: an increasing topical and oral threat

Topical and oral antibiotics are routinely used to treat acne. However, antibiotic resistance is increasing, with many countries reporting that more than 50% of Propionibacterium acnes strains are resistant to topical macrolides, making them less effective. We reviewed the current scientific literature to enable proposal of recommendations for antibiotic use in acne treatment. References were identified through PubMed searches for articles published from January, 1954, to March 7, 2015, using four multiword searches. Ideally, benzoyl peroxide in combination with a topical retinoid should be used instead of a topical antibiotic to minimise the impact of resistance. Oral antibiotics still have a role in the treatment of moderate-to-severe acne, but only with a topical retinoid, benzoyl peroxide, or their combination, and ideally for no longer than 3 months. To limit resistance, it is recommended that benzoyl peroxide should always be added when long-term oral antibiotic use is deemed necessary. The benefit-to-risk ratio of long-term antibiotic use should be carefully considered and, in particular, use alone avoided where possible. There is a need to treat acne with effective alternatives to antibiotics to reduce the likelihood of resistance.

Inflammatory Acne in the Asian Skin Type III Treated with a Square Pulse, Time Resolved Spectral Distribution IPL System: A Preliminary Study

BACKGROUND AND AIMS

Acne remains a severe problem for both patients and clinicians. Various approaches using photosurgery and phototherapy have been reported with varying degrees of success and robustness of results. An improved intense pulsed light (IPL) system has become available with interesting beam characteristic which might improve IPL treatment of inflammatory acne in the Asian skin, Fitzpatrick type III/IV.

SUBJECTS AND METHODS

The 18 study subjects comprised 15 females and 3 males with active mild to moderately severe inflammatory acne (mean age 25.3 ± 7.70 yr, range 17-47 yr, Burton scale 1-4, all Fitzpatrick type III Asian skin). They were treated once (8 subjects) or twice (10 subjects) with an IPL system offering both square pulse and time resolved spectral distribution technologies (420 nm cut-off filter, 30 ms pulse, 8 - 12 J/cm(2), 2-3 passes). Clinical photography was taken at baseline and at 4 weeks after the final treatment. Percentage of acne clearance was assessed by an independent dermatological panel and graded from zero to 5, 5 being total clearance.

RESULTS

All subjects completed the study. Post-treatment side effects were mild and transient, with virtually no downtime or postinflammatory hyperpigmentation (PIH) experienced by any subject. All subjects had some improvement and no exacerbation was seen in any subject. Clearance was evaluated by the panel as grade 4 in 5 subjects, grade 3 in 8, grade 2 in 4 and grade 1 in 1, so that 14 of 18 subjects (78%) had clearance of at least 60%. Patient evaluation was in general slightly better than that of the panel.

CONCLUSIONS

The special beam characteristics of the IPL system used in the present preliminary study achieved good to very good results in the treatment of acne in the Fitzpatrick type III Asian skin without PIH induction. The results suggested that acne treatment in the Asian skin using this system is both safe and effective, and merits larger population studies to further optimize parameters and standardize top-up treatments.

0.5% Liposome-encapsulated 5-aminolevulinic acid (ALA) photodynamic therapy for acne treatment

BACKGROUND

Photodynamic therapy using topical 5-aminolevulinic acid (ALA) has been successful in treating acne vulgaris, but sun avoidance for at least 48 hours after treatment is necessary due to the risk of post-treatment photosensitivity. Recently, a lower concentration of liposome-encapsulated 5-ALA was introduced to minimize this risk.

OBJECTIVES

To evaluate the efficacy and safety of liposome-encapsulated 0.5% 5-ALA in the photodynamic therapy of inflammatory acne and its effects on sebum secretion in Asian skin.

METHODS

Thirteen Korean subjects with inflammatory acne were administered 0.5% ALA spray before photoradiation treatment. Photoradiation was performed at 3.5-6.0 J/cm(2) three times during each of two visits, performed 2 weeks apart. Improvement of acne was evaluated subjectively and objectively based on the Korean Acne Grading System. Sebum secretion was measured quantitatively at each visit.

RESULTS

The mean reduction in acne grade at the end of the treatment was 43.2%. Of the patients, 69.2% reported improvements in subjective skin oiliness, but fewer showed objective reductions in sebum secretion as determined by the Sebumeter® SM10. No serious adverse events were observed.

CONCLUSION

Photodynamic therapy using liposome-encapsulated 0.5% 5-ALA improved inflammatory acne with minimal side effects in Asians.

Acne vulgaris treatment : the current scenario

Acne Vulgaris is one of the most common skin disorders which dermatologists have to treat. It mainly affect adolescent, though may present at any age. In recent years, due to better understanding of the pathogenesis of acne, new therapeutic modalities and various permutation and combinations have been designed. In topical agents; benzoyl peroxide, antibiotics, retinoids, etc are the mainstay of treatment; can be given in combinations. While systemic therapy includes oral antibiotics, hormonal therapy, and isotretinoin, depending upon the need of patients it has to be selected. Physical treatment in the form of lesion removal, photo-therapy is also helpful in few of them. Since various old and new topical and systemic agents are available to treat acne, it sometime confuse treating dermatologist. To overcome this, panel of physicians and researchers worked together as a global alliance and task force to improve outcomes in acne treatment. They have tried to give consensus recommendation for the treatment of acne. Successful management of acne needs careful selection of anti-acne agents according to clinical presentation and individual patient needs.

About local administration of antibacterial drugs for acne therapy

The review summarizes and systematizes data accumulated in the world research literature, which are related to the role of P. acnes in the pathogenesis of acne, its microbiology and antibacterial resistance; it also examines antibacterial drugs for the external therapy of acne and recommendations for their use.

Dermatology for the allergist

Abstract:

Allergists/immunologists see patients with a variety of skin disorders. Some, such as atopic and allergic contact dermatitis, are caused by abnormal immunologic reactions, whereas others, such as seborrheic dermatitis or rosacea, lack an immunologic basis. This review summarizes a select group of dermatologic problems commonly encountered by an allergist/immunologist.

The role of Propionibacterium acnes in acne pathogenesis: facts and controversies

We have come a long way since 1896, when it was first suggested that Propionibacterium acnes, found in acne lesions, was the cause of acne. Although several lines of evidence suggest the direct role of P acnes in acne, the mechanism by which P acnes contributes to the pathogenesis of acne is debated. The importance of P acnes in the induction and maintenance of the inflammatory phase of acne has been established. Emerging data that inflammatory events occur in the very earliest stages of acne development have reopened the debate about the potential involvement of this microorganism in comedogenesis and acne initiation.

In vitro susceptibility to selected antibiotics in bacteria of the Bacteroides fragilis group

Susceptibility of strains of Bacteroides fragilis group (1284 isolates from cancerous and noncancerous patients in 1994-2004) showed an increase in resistance toward some antibiotics (by 9 % toward penicillin and 8 % toward clindamycin) compared with the resistance level of 10 years ago. The increase in resistance was not detected in the case of ampicillin + sulbactam and metronidazole.

The use of isotretinoin in acne

Systemic isotretinoin remains the most efficacious treatment for severe acne as well as many cases of more moderate disease that are unresponsive to other treatment modalities. The current chapter outlines the mechanisms behind the excellent efficacy, describes how to optimize treatment, reviews the recommended guidelines for monitoring and summarizes adverse effects.

Optimizing use of oral antibiotics in acne vulgaris

Oral antibiotics are commonly used to treat acne vulgaris, primarily in patients presenting with moderate to severe facial or truncal disease severity. These agents are most appropriately used in combination with a topical regimen containing benzoyl peroxide and a topical retinoid. The most common oral antibiotics for treating acne vulgaris are the tetracycline derivatives, although macrolide agents such as erythromycin have also been used extensively. Over the past 4 decades, as the sensitivity of Propionibacterium acnes to several oral and topical antibiotics has decreased, the efficacy of oral tetracycline and erythromycin has markedly diminished, leading to increased use of doxycycline, minocycline, and other agents, such as trimethoprim/sulfamethoxazole.

Double-blind, randomized, placebo-controlled study of a lotion containing triethyl citrate and ethyl linoleate in the treatment of acne vulgaris

BACKGROUND

Acne vulgaris is a major clinical problem; despite a vast array of treatment modalities available for acne, there is considerable dissatisfaction in acne treatment among patients and doctors. Rising antibiotic drug resistance consequent to the widespread use of topical antibiotics is causing concern and effective nonantibiotic treatments are needed.

OBJECTIVES

To evaluate the efficacy and tolerability of a novel lotion containing triethyl citrate and ethyl linoleate in the treatment of mild to moderate acne vulgaris.

METHODS

This was a double-blind, placebo-controlled, randomized study comparing the active lotion containing triethyl citrate and ethyl linoleate with its vehicle as a placebo control. Patients were assessed by the modified Leeds acne grading system as well as by counting inflammatory and noninflammatory lesions on the face at weeks 0, 4, 8 and 12. Sebum production was assessed by the Sebutape method at weeks 0 and 12. All adverse events were recorded.

RESULTS

Forty patients were recruited into the study, of whom 33 completed the study. Active treatment was statistically superior to placebo in reduction of Leeds grading and total, inflammatory and noninflammatory lesion counts. The active lotion showed a rapid response with obvious reduction in lesion counts and acne grading by 4 weeks. Sebum production was significantly reduced in the actively treated group, with a mean reduction of 53% in sebum production compared with baseline. One patient developed irritation to the active lotion and withdrew from the study.

CONCLUSIONS

The new lotion containing triethyl citrate and ethyl linoleate has been shown to be an effective treatment for mild to moderate acne, with an effect on both inflammatory and noninflammatory acne lesions. The new lotion worked quickly and was generally well tolerated. A surprising finding was the significant impact the new lotion has on sebum production, suggesting a role in patients with seborrhoea. This nonantibiotic preparation will be a very useful addition to existing treatments for acne.

Blue and red light combination LED phototherapy for acne vulgaris in patients with skin phototype IV

BACKGROUND AND OBJECTIVES

Blue light is effective for acne treatment, inducing photodynamic destruction of Propionibacterium acnes (P. acnes). This study was designed to investigate the efficacy of combined blue and red light-emitting diode (LED) phototherapy for acne vulgaris.

MATERIALS AND METHODS

Twenty-four patients with mild to moderately severe facial acne were treated with quasimonochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. The treatment was performed twice a week for 4 weeks. Objective assays of the skin condition were carried out before and after treatment at each treatment session. Clinical assessments were conducted before treatment, after the 2nd, 4th, and 6th treatment sessions and at 2, 4, and 8 weeks after the final treatment by grading and lesion counting.

RESULTS

The final mean percentage improvements in non-inflammatory and inflammatory lesions were 34.28% and 77.93%, respectively. Instrumental measurements indicated that the melanin levels significantly decreased after treatment. Brightened skin tone and improved skin texture were spontaneously reported by 14 patients.

CONCLUSION

Blue and red light combination LED phototherapy is an effective, safe and non-painful treatment for mild to moderately severe acne vulgaris, particularly for papulopustular acne lesions.

Treatment of acne vulgaris without antibiotics: tertiary amine?benzoyl peroxide combination vs. benzoyl peroxide alone (Proactiv Solution?)

BACKGROUND

Concerns have arisen over the development of antibiotic-resistant organisms due to the prolonged use of oral and topical antibiotics in acne vulgaris. We have previously demonstrated that benzoyl peroxide used in consort with a chemical with an accessible tertiary amine, such as an allylamine, increases radical activity and biological effect.

OBJECTIVES

The purpose of this pilot study was to assess the efficacy of two nonantibiotic topical remedies for mild to moderate acne, with one of the agents being a combination of benzoyl peroxide with butenifine, an allylamine.

METHODS

In an open-label, patient-satisfaction, 8-week comparative study, 23 patients demonstrating mild to moderate facial acne were given randomly either benzoyl peroxide in Proactiv Solution or the combination of benzoyl peroxide with an allylamine.

RESULTS

The allylamine-benzoyl peroxide combination therapy outperformed Proactiv Solution during each 2-week stage of evaluation in terms of reduction of comedones, inflammatory lesions, and degree of oiliness. There was a marked preference for the allylamine-benzoyl peroxide combination in terms of patient satisfaction.

CONCLUSIONS

Benzoyl peroxide used in consort with antimicrobial agents that contain an accessible tertiary amine, such as erythromycin, has previously been shown to increase radical activity and biological effect. Trials of short duration with small numbers of patients do not adequately inform practitioners about whether the combination of allylamines with benzoyl peroxide is a viable alternative to topical antibiotic therapy for acne. Nevertheless, the higher satisfaction with the allylamine-benzoyl peroxide combination certainly warrants further investigation.

Lasers alleviate acne

Propionibacterium acnes (P. acnes) and sebaceous glands are involved in the pathogenesis of acne. Although often effective, traditional therapies can have drawbacks, such as photosensitivity, other toxicities, polypharmacy and frequent dosing. Lasers have been studied to seek a solution that may overcome these disadvantages. Lasers and other light therapies target the wavelengths of the porphyrins in P. acnes to induce thermal damage that causes the bacterium's destruction. Pulsed-dye laser (PDL) or a system of light pulses and heat with wavelengths between 430 and 1100 nm are both efficacious. The 1450-nm diode laser targets sebaceous glands and is also effective. Topical indocyanine green (ICG) photodynamic therapy (PDT), using the near-infrared (NIR) laser, targets either P. acnes or sebaceous glands. ICG-PDT has fewer adverse effects than aminolevulinic acid-PDT. Lasers are still a relatively new therapy for acne and may be best used in an adjuvant role.

The effectiveness of intermittent isotretinoin treatment in mild or moderate acne

BACKGROUND

Isotretinoin is the only drug that affects almost all factors in acne pathogenesis. Recently, its use for the treatment of chronic mild or moderate acne unresponsive to long-term antibiotic therapy, and with a tendency to cause scarring and leading to negative psychological effects, has became popular. The aim of the study was to investigate the effectiveness of intermittent isotretinoin treatment in mild or moderate acne.

METHODS

Sixty patients with mild or moderate acne localized to the face were enrolled in the study. The treatment regimen consisted of isotretinoin, 0.5-0.75 mg/kg per day, applied for 1 week every 4 weeks for a total period of 6 months, according to the degree of acne and number of inflammatory lesions.

RESULTS

Forty-one (68.3%) of the 60 patients completed the 6-month therapy. At the end of the treatment complete improvement was observed in 34 patients (82.9%) out of 41. All adverse effects were mild and discontinuation of the treatment was not necessary.

CONCLUSION

Intermittent isotretinoin treatment was found to be a safe and effective choice for patients with mild or moderate acne.

Expert committee recommendations for acne management

In 2003, an international committee of physicians and researchers in the field of acne, working together as the Global Alliance to Improve Outcomes in Acne, developed consensus guidelines for the treatment of acne. These guidelines were evidence based when possible but also included the extensive clinical experience of this group of international dermatologists. As a result of the evaluation of available data and the experience, significant changes occurred in the management routines for acne. The greatest change arose on the basis of improved understanding of acne pathophysiology. The recommendation now is that acne treatments should be combined to target as many pathogenic factors as possible. A topical retinoid should be the foundation of treatment for most patients with acne, because retinoids target the microcomedo, the precursor to all acne lesions. Retinoids also are comedolytic and have intrinsic antiinflammatory effects, thus targeting 2 pathogenic factors in acne. Combining a topical retinoid with an antimicrobial agent targets 3 pathogenic factors, and clinical trials have shown that combination therapy results in significantly faster and greater clearing as opposed to antimicrobial therapy alone. Oral antibiotics should be used only in moderate-to-severe acne, should not be used as monotherapy, and should be discontinued as soon as possible (usually within 8-12 weeks). Because of their effect on the microcomedo, topical retinoids also are recommended as an important facet of maintenance therapy.

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.

A review on the treatment of acne vulgaris

The following article reviews treatment for acne vulgaris. Selection of therapy should be based on clinical appearance taking into account lesion type and severity, as well as identification of acne scarring and the psychosocial disability caused by the disease.

Treatment of acne with topical antibiotics: lessons from clinical studies

BACKGROUND

Over the past 20 years, major concerns have been repeatedly expressed over antibiotic-resistant acne in Europe and in the U.S.A. However, the clinical significance of these resistance patterns is poorly defined so that topical antibiotics remain one of the cornerstones of acne management.

OBJECTIVES

To determine whether we are facing decreased efficacy of topical formulations of erythromycin and clindamycin in clinical trials of therapeutic interventions for acne.

METHODS

To review systematically the results of the clinical trials investigating topical formulations of erythromycin and clindamycin for the treatment of inflammatory acne and to establish whether or not there is a decrease in the efficacy of these topical antibiotic formulations since their widespread introduction in the mid 1970s.

RESULTS

Of the 50 eligible controlled trials identified using a systematic electronic database search strategy, 45 (90%) incorporated a lesion count, making comparison across trials possible. Analysis of clinical studies investigating the effect of topical erythromycin in acne patients indicates a significant decrease in the effect of this antibiotic on inflammatory and noninflammatory lesion count over time (r = -2.140, P = 0.001 and r = -2.032, P = 0.001, respectively). Efficacy of topical clindamycin remained stable during the study period.

CONCLUSIONS

There is a gradual decrease in the efficacy of topical erythromycin in clinical trials of therapeutic intervention for acne, which is probably related to the development of antibiotic-resistant propionibacteria.

Inflammation and extracellular matrix degradation mediated by activated transcription factors nuclear factor-kappaB and activator protein-1 in inflammatory acne lesions in vivo

Acne is the most common skin disease, causing significant psychosocial problems for those afflicted. Currently available agents for acne treatment, such as oral antibiotics and isotretinoin (Accutane), have limited use. Thus, development of novel agents to treat this disease is needed. However, the pathophysiology of acne inflammation is poorly understood. Before new therapeutic strategies can be devised, knowledge regarding molecular mechanisms of acne inflammation is required. We report here that transcription factors nuclear factor-kappaB and activator protein-1 are activated in acne lesions with consequent elevated expression of their target gene products, inflammatory cytokines and matrix-degrading metalloproteinases, respectively. These elevated gene products are molecular mediators of inflammation and collagen degradation in acne lesions in vivo. This new knowledge enables a rational strategy for development of pharmacological agents that can target the inflammation and matrix remodeling that occurs in severe acne.

Comparison of efficacy of azithromycin vs. doxycycline in the treatment of acne vulgaris

Acne vulgaris is a common inflammatory disorder of the skin. Oral antibiotics are known to be effective in its treatment. A randomized, investigator-blinded study was performed to compare the efficacy of azithromycin with doxycycline. Fifty-one patients were randomized to receive either azithromycin 500 mg/day on 3 consecutive days per week in the first, on 2 consecutive days per week in the second, and on 1 day per week in the third month. The other group was given doxycycline twice a day for the first month and once a day for the second and third months. Clinical assessment was made at baseline, at the end of first, second, third, and post-treatment first and second months. Side effects were recorded. Statistically significant improvement for the facial lesions were obtained with both drugs. Neither drug was shown to be more effective than the other. The beneficial effect continued until 2 months after treatment. In the azithromycin group three patients had diarrohea, while photosensitivity was seen in two patients using doxycycline. This study indicates that azithromycin is at least as effective as doxycycline in the treatment of acne.

European surveillance study on the antibiotic susceptibility of Propionibacterium acnes

Propionibacterium acnes strains are recovered from infections linked to surgical procedures, foreign bodies and septicaemia. This study investigated the antibiotic susceptibility patterns of P. acnes isolates from different systemic infections and determined the genomic diversity among resistant P. acnes isolates with low-frequency restriction analysis of chromosomal DNA by pulsed-field gel electrophoresis (PFGE). In total, 304 P. acnes isolates from 13 laboratories in 13 European countries were tested against six antimicrobial agents by the NCCLS reference agar dilution method and the breakpoints recommended by the European Committee on Antimicrobial Susceptibility Testing. Blood isolates were encountered most frequently, followed by those from skin and soft tissue infections, and abdominal infections. Of the isolates examined, 2.6% were resistant to tetracycline, 15.1% to clindamycin, and 17.1% to erythromycin. No resistance was observed to linezolid, benzylpenicillin or vancomycin. There was considerable variation between countries in the proportion of resistant strains, ranging from 83% in Croatia and 60% in Italy to 0% in The Netherlands. Isolates from blood were predominant among the resistant isolates. Seventeen clones and 78 banding patterns were identified among the resistant isolates. It was concluded that antimicrobial resistance has now emerged among P. acnes isolates from systemic infections.

Acne and Propionibacterium acnes

The involvement of microorganisms in the development of acne has a long and checkered history. Just over 100 years ago, Propionibacterium acnes (then known as Bacillus acnes) was isolated from acne lesions, and it was suggested that P. acnes was involved in the pathology of the disease. The 1960s saw the use of antibiotics to treat acne, and the consequent clinical success combined with reductions in P. acnes gave new impetus to the debate. Over the past two decades, the inevitable emergence of antibiotic-resistant strains of P. acnes as a consequence of acne therapy not only has reopened the debate as to the role of P. acnes in acne, but also has created some serious health care implications.

Blue light phototherapy in the treatment of acne

BACKGROUND

Blue light irradiation is known to be effective against acne. However, the profile of a good candidate is still unclear.

METHODS

Thirty-one Taiwanese with symmetrical facial acne were irradiated with blue light on one side of the face selected randomly twice weekly for 4 consecutive weeks. The other half of the face was left untreated as control. Parameters, including scar type, pore size, and facial follicular porphyrin fluorescence intensity, were documented. The severity of acne was assessed before the treatment, after two, four, and eight sessions of treatment, and 1 month after the treatment was completed.

RESULTS

Compared with the non-irradiation side, eight sessions of blue light irradiation were effective in acne treatment (P<0.001). Gender (P=0.471), scar type (P-values of pitted, atrophic, and hypertrophic type were 0.688, 0.572, and 0.802, respectively), pore size (P=0.755), and pretreatment fluorescence intensity (P=0.656) could not be used as predictive factors of therapeutic effectiveness. Compared with pretreatment, nodulocystic lesions tended to worsen despite treatment. In addition, the therapeutic effectiveness was not related to the fluorescence intensity change (P=0.812).

CONCLUSIONS

Blue light irradiation is effective in acne treatment. Patients without nodulocystic lesions are better candidates for blue light irradiation.

15 % Azelainsauregel in der Behandlung der Akne. Zwei doppelblinde klinische Vergleichsstudien. Azelaic acid 15 % gel in the treatment of acne vulgaris. Combined results of two double-blind clinical comparative studies

BACKGROUND

Topical measures are still the mainstay in the therapy of mild-to-moderate acne vulgaris. Azelaic acid 20% in a cream formulation has been established as an efficacious and safe topical drug for 15 years. A new non-alcoholic hydrogel formulation containing 15% azelaic acid was clinically tested against two standard drugs--5% benzoyl peroxide (BPO) and 1% clindamycin.

PATIENTS AND METHODS

In two independent, randomized, blinded comparative trials 15% azelaic acid gel was clinically tested against 5% benzoyl peroxide (BPO) gel in 351 patients and against 1% clindamycin gel in 229 patients. The drugs were applied b.i.d. for 4 months.

RESULTS

Azelaic acid 15% gel proved to be as effective as BPO and clindamycin with median % reduction of the inflamed lesion (papules and pustules) of 70%, and 71% respectively. The azelaic acid gel was well-tolerated, the side effects (local burning and irritation) were distinctly less than with BPO but more pronounced than with clindamycin. Despite these side effects, the treatment was well-accepted by the majority of patients.

CONCLUSIONS

Azelaic acid gel is an effective topical monotherapy for mild-to-moderate acne vulgaris; its new gel form is an enrichment of acne therapy.