Management of acne: a report from a Global Alliance to Improve Outcomes in Acne

Induction of toll-like receptors by Propionibacterium acnes

BACKGROUND

The bacterium Propionibacterium acnes is involved in the induction and maintenance of the inflammatory phase of acne. Recent studies have found that keratinocytes express toll-like receptors (TLRs) implicated in immediate immunity. No studies have, to date, been carried out on the action of P. acnes upon TLR activation in keratinocytes.

OBJECTIVES

Focusing on the inflammatory phase of acne, to clarify the role of P. acnes in immediate immunity by inducing expression of TLR-2 and TLR-4 by keratinocytes. We also studied how the secretion and expression of matrix metalloproteinase (MMP)-9 is induced by P. acnes.

METHODS

The work was carried out on two levels: in vivo with the study of the expression of TLR-2 and TLR-4 proteins in biopsies of acne lesions and in vitro on cultured keratinocyte monolayers to study the modulating effects of P. acnes on the expression of TLR-2 and TLR-4 and also on the expression and secretion of MMP-9.

RESULTS

Our findings reveal that in vivo TLR-2 and TLR-4 expression is increased in the epidermis of acne lesions. In vitro, an increase in TLR-2 and TLR-4 expression by human keratinocytes occurred in the first hours of incubation with bacterial fractions as well as an increase of the expression and secretion by the keratinocytes of MMP-9, which plays a role in inflammation.

CONCLUSIONS

This work demonstrates that P. acnes induces TLR expression and that this mechanism could play an essential role in acne-linked inflammation. These receptors could be involved notably in acute acne.

Matrix metalloproteinases of epithelial origin in facial sebum of patients with acne and their regulation by isotretinoin

Acne vulgaris is a skin disorder of the sebaceous follicles, involving hyperkeratinization and perifollicular inflammation. Matrix metalloproteinases (MMP) have a predominant role in inflammatory matrix remodeling and hyperproliferative skin disorders. We investigated the expression of MMP and tissue inhibitors of MMP (TIMP) in facial sebum specimens from acne patients, before and after treatment with isotretinoin. Gelatin zymography and Western-blot analysis revealed that sebum contains proMMP-9, which was decreased following per os or topical treatment with isotretinoin and in parallel to the clinical improvement of acne. Sebum also contains MMP-1, MMP-13, TIMP-1, and TIMP-2, as assessed by ELISA and western blot, but only MMP-13 was decreased following treatment with isotretinoin. The origin of MMP and TIMP in sebum is attributed to keratinocytes and sebocytes, since we found that HaCaT keratinocytes in culture secrete proMMP-2, proMMP-9, MMP-1, MMP-13, TIMP-1, and TIMP-2. SZ95 sebocytes in culture secreted proMMP-2 and proMMP-9, which was also confirmed by microarray analysis. Isotretinoin inhibited the arachidonic acid-induced secretion and mRNA expression of proMMP-2 and -9 in both cell types and of MMP-13 in HaCaT keratinocytes. These data indicate that MMP and TIMP of epithelial origin may be involved in acne pathogenesis, and that isotretinoin-induced reduction in MMP-9 and -13 may contribute to the therapeutic effects of the agent in acne.

Pathophysiologie der Akne

Several pathogenic factors contribute to the development of acne, among them, seborrhea, follicular hyperkeratosis, propionibacteria, and inflammatory events. This article reviews current knowledge of these pathogenic factors.

Systemische Aknetherapie

The development of scarring in inflammatory acne may induce permanent disfigurement and considerable psychosocial impact on the lives of affected individuals. The early use of systemic acne therapy can help to prevent these unfortunate consequences. Antiinflammatory antibiotics such as tetracyclines are required in moderate to severe papulopustular acne. The recommended treatment duration is 3 months; combination with topical retinoids and benzoyl peroxide increases the speed and efficacy of lesion reduction and helps to prevent bacterial resistance. Oral isotretinoin is the treatment of choice in severe acne resistant to adequate conventional therapy. Hormonal treatment represents an alternative regimen for women with acne and is the first choice in late-onset acne and in those with clinical signs of hyperandrogenism.

Combination therapy with adapalene gel 0.1% and doxycycline for severe acne vulgaris: a multicenter, investigator-blind, randomized, controlled study

BACKGROUND

Combination therapy with a topical retinoid and an antibiotic is recognized as a rational and effective approach for the treatment of acne vulgaris. Adapalene, a naphthoic acid derivative with anti-inflammatory and receptor-selective retinoid properties, is safe and well tolerated. While the combination of adapalene with oral or topical antibiotics has been shown to deliver a superior and faster response than an antibiotic alone, the clinical benefits of a combination of adapalene and doxycycline, the most frequently prescribed oral antibiotic for acne in the United States, have yet to be evaluated.

OBJECTIVE AND METHODS

In a 12-week study, the efficacy and safety of the combination of adapalene gel 0.1% with doxycycline was compared with doxycycline alone for the treatment of severe acne. Subjects were randomized to receive doxycycline once daily in the morning and either adapalene or vehicle once daily in the evening.

RESULTS

At Week 12, the combination adapalene-doxycycline was significantly superior to doxycycline alone for change from baseline in total (p<0.001), inflammatory (p=0.02), and noninflammatory (p<0.001) lesions. Significant differences in total lesions were observed as early as Week 4 (p=0.04). Both treatments were well tolerated, and no serious adverse events were reported.

CONCLUSIONS

The study demonstrates that the combination of adapalene and an oral antibiotic provides a superior and faster benefit than antibiotic therapy alone and should be considered at the initiation of treatment.

RALGA (Diacnéal®), a Retinaldehyde and Glycolic Acid Association and Postinflammatory Hyperpigmentation in Acne – A Review

Acne vulgaris affects 3 out of 4 adolescents and usually vanishes at the end of puberty with either no sequelae or mild to moderate sequelae, such as postinflammatory hyperpigmenation (PIH), which may result in psychological and emotional damages. The poor tolerability of the actual treatments (secondary inflammation) is a hindrance to therapy. Retinaldehyde (RAL), a precursor of retinoic acid, has shown depigmenting activity. Glycolic acid (GA) decreases the excess of pigment by a wounding and re-epithelization process. Thus, a synergistic effect was expected from the combination of RAL 0.1% and GA 6% RALGA (Diacneal) in the treatment of acne vulgaris and PIH. Efficacy results of preclinical and clinical trials tend to confirm the expectations for both acne and PIH treatment. A good tolerability was observed. In conclusion, the cosmetic cream Diacneal is a well-tolerated treatment for the prevention and healing of PIH in acne patients.

Topical Retinaldehyde with Glycolic Acid: Study of Tolerance and Acceptability in Association with Anti-Acne Treatments in 1,709 Patients

BACKGROUND

Retinaldehyde (RAL), a key metabolite between vitamin A and retinoic acid, acts by modulating differentiation and proliferation of keratinocytes, which is of interest in acne lesions, mainly retentional lesions. Glycolic acid increases the exfoliation of corneocytes explaining its mild activity on retentional lesions. Thus, RAL and glycolic acid combined in the same product (Diacneal) have complementary activities which can be of interest for acne patients. The aim of this study was to evaluate the tolerance of Diacneal used by 1,709 acne patients in combination with their usual acne products except retinoids.

RESULTS

This study demonstrated a very good tolerance of Diacneal when used with other acne treatments for 90 days. Complaints about side-effects were rare. Moreover, the significant decrease in both inflammatory and retentional lesions between day 0 and day 90 indicates that Diacneal could amplify the efficiency of other anti-acne products used at the same time by the patients. The subjective evaluation of the preparation's efficacy by investigators and patients was strongly favourable.

CONCLUSION

These data show that a combination of RAL 0.1% and glycolic acid 6% may be used in association with other topical anti-acne treatments (benzoyl peroxide and topical antibiotics) with an excellent tolerance.

Topical antibacterial therapy for acne vulgaris

Topical antibiotics and benzoyl peroxide, are the two main topical antibacterial treatments indicated for mild-to-moderate acne vulgaris. Topical antibiotics act both as antibacterial agents suppressing Propionibacterium acnes in the sebaceous follicle and as anti-inflammatory agents. Benzoyl peroxide is a powerful antimicrobial agent that rapidly destroys both bacterial organisms and yeasts. Topical clindamycin and erythromycin have been proven to be effective against inflammatory acne vulgaris in concentrations of 1-4% with or without the addition of zinc. However, none of the antibacterials tested was more effective than benzoyl peroxide, which also has the advantage of not being associated with antimicrobial resistance. Topical antibacterial therapy should be discontinued once improvement is observed. If no improvement is observed within 6-8 weeks, the agent should be discontinued and a therapeutic switch considered. The primary limitation of benzoyl peroxide for some acne vulgaris patients is cutaneous irritation or dryness.Antibacterial therapy can be used in combination with other agents. Combining topical antibiotics and topical retinoids may enhance the efficacy, since the retinoid will improve the penetration of the antibiotic. Combining a topical antibiotic with benzoyl peroxide may increase the bactericidal effect of the antibiotic and reduce the potential for bacterial resistance. Topical and oral antibacterials should not be used in combination for the treatment of acne vulgaris, since this association may increase the risk of bacterial resistance.

Erganzende Verfahren in der Aknetherapie. Adjunctive acne therapies

The mainstays of modern acne therapy include comedolytic, antimicrobial, and anti-inflammatory substances, as well as antiandrogens. Additionally, traditional or newly developed therapeutic approaches may be considered, including pharmacologic (dapsone, zinc) and physical measures (phototherapy, photodynamic therapy, comedone extraction, abrasives). This article reviews such adjunctive therapies with regard to efficacy and their roles in acne therapy.

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.

Acne: Topical treatment

Acne vulgaris is a common skin disease, affecting about 70-80% of adolescents and young adults. It is a multifactorial disease of the pilosebaceous unit.(1) The influence of androgens at the onset of adolescence leads to an enlargement of the sebaceous gland and a rise in sebum production. Additional increased proliferation and altered differentiation of the follicular epithelium eventually blocks the pilosebaceous duct, leading to development of the microcomedo as the primary acne lesion. Concomitantly and subsequently, colonization with Propionibacterium acnes increases, followed by induction of inflammatory reactions from bacteria, ductal corneocytes, and sebaceous proinflammatory agents (Fig 1).(2-5)

Guidelines for treating acne

Acne, a chronic inflammatory disease of the pilosebaceous units of the face, neck, chest, and back, is the most common skin disorder occurring universally, with an estimated prevalence of 70-87%.(1) It is a pleomorphic disorder characterized by both inflammatory (papules, pustules, nodules) and noninflammatory (comedones, open and closed) lesions. Grading of acne is mandatory to determine the appropriate therapeutic strategy. Mild acne can be purely comedonal or mild papulopustular, with a few papulopustules present as well.(2) Moderate acne is characterized by numerous comedones, few to many pustules, and few small nodules, with no residual scarring.(2) In severe acne papulopustules are numerous, many nodules can be detected, inflammation is marked, and scarring is present.(2) Very severe acne can be recognized by sinus tracts, grouped comedones, many deeply located nodules, and severe inflammation and scarring.(2) Although acne does not affect health overall, its impact on emotional well-being and function can be critical and is often associated with depression, anxiety, and higher-than-average unemployment rates.(3) Effective treatment can dramatically improve a person's quality of life.

Acne update: 2004

PURPOSE OF REVIEW

Acne vulgaris is a common skin disorder among children and young adults that carries enormous financial and psychosocial impact. Contemporary therapies attempt to address factors underlying acne as a disorder of the pilosebaceous unit. These longstanding paradigms regarding pathogenesis and treatment continue to evolve in light of recent work on this ubiquitous disease.

RECENT FINDINGS

This review focuses on new literature that has emerged regarding the biology of the folliculosebaceous unit, the identification of particular mediators responsible for inflammatory acne, the use of topical and systemic retinoids in acne therapy, and approaches to address the emergence of antibiotic-resistant Propionibacterium acnes strains. In addition, the use of several novel therapeutic avenues is discussed, including combination therapies, lipoxygenase inhibitors, and lasers.

SUMMARY

As the understanding of the factors that initiate and exacerbate acne vulgaris continues to increase, so does the diversity of therapeutic options. Rational use of available treatment options based on the type and severity of acne lesions is a key component of successful acne therapy and allows the physician who treats adolescents with acne to provide optimum care.

Antibiotic-resistant Propionibacterium acnes on the skin of patients with moderate to severe acne in Stockholm

The objective was to study the prevalence and antibiotic susceptibility patterns of Propionibacterium acnes strains isolated from patients with moderate to severe acne in Stockholm, Sweden and to determine the diversity of pulsed-field gel electrophoresis types among resistant P. acnes strains. One hundred antibiotic-treated patients and 30 non-antibiotic-treated patients with moderate to severe acne participated in the investigation. Facial, neck and trunk skin samples were taken with the agar gel technique. The susceptibility of P. acnes strains to tetracycline, erythromycin, clindamycin and trimethoprim-sulfamethoxazole was determined by the agar dilution method. The genomic profiles of the resistant strains were determined by pulsed-field gel electrophoresis. In the group of patients treated with antibiotics, resistant P. acnes strains were recovered in 37%, while in the non-antibiotic group of patients the incidence of resistant strains was 13%. Thus antibiotic-resistant P. acnes strains were significantly more often isolated from antibiotic-treated patients with moderate to severe acne than from non-antibiotic-treated patients (odds ratio, 3.8; P=0.01). There was a genetic diversity among the P. acnes strains. Forty-four different patterns of SpeI DNA digests were detected and two predominant clones were found. P. acnes strains exhibited different antibiotic susceptibility patterns and identical genotypes or vice versa. A person can be colonized with different strains with varying degrees of antibiotic resistance. The risk of increased resistance of P. acnes must be considered when treating acne patients with antibiotics, and especially long-term therapy should be avoided.

Systemic therapy for acne vulgaris

There are three main groups of systemic therapies available for the treatment of acne vulgaris: systemic antibiotics, hormonal therapy (for females) and oral isotretinoin. This article outlines when these treatments should be prescribed for the treatment of acne, considers the impact of therapy on aetiology, and advises on dosage regimens, potential adverse effects and expected efficacy.

Maintenance therapy for acne vulgaris: the fine balance between efficacy, cutaneous tolerability, and adherence

Maintenance therapy is defined as the regular use of appropriate therapeutic agents to ensure that acne remains in remission. Topical agents are the mainstay of maintenance therapy. A number of topical therapeutic options are available, including topical retinoids, benzoyl peroxide, and azelaic acid. The choice of topical agents should be based on a number of criteria: efficacy in addressing the subclinical microcomedo, which is the precursor lesion for both comedones and inflammatory lesions; tolerability, due to the need for application to a broader epidermal surface; and other properties that may enhance adherence. Patients may be more motivated to use agents that are easily integrated into their lifestyles and that have potential "skin-repairing" properties.

Adapalene

Adapalene (Differin) is a retinoid agent indicated for the topical treatment of acne vulgaris. In clinical trials, 0.1% adapalene gel has proved to be effective in this indication and was as effective as 0.025% tretinoin gel, 0.1% tretinoin microsphere gel, 0.05% tretinoin cream and 0.1% tazarotene gel once every two days; however, the drug was less effective than once-daily 0.1% tazarotene gel. It can be used alone in mild acne or in combination with antimicrobials in inflammatory acne and has proved efficacious as maintenance treatment. Adapalene has a rapid onset of action and a particularly favourable tolerability profile compared with other retinoids. These attributes can potentially promote patient compliance, an important factor in treatment success. Adapalene is, therefore, assured of a role in the first-line treatment of acne vulgaris.