Tetracycline and acne vulgaris: a clinical and laboratory investigation

Early development of the skin microbiome: therapeutic opportunities

As human skin hosts a diverse microbiota in health and disease, there is an emerging consensus that dysregulated interactions between host and microbiome may contribute to chronic inflammatory disease of the skin. Neonatal skin is a unique habitat, structurally similar to the adult but with a different profile of metabolic substrates, environmental stressors, and immune activity. The surface is colonized within moments of birth with a bias toward maternal strains. Initial colonists are outcompeted as environmental exposures increase and host skin matures. Nonetheless, early life microbial acquisitions may have long-lasting effects on health through modulation of host immunity and competitive interactions between bacteria. Microbial ecology and its influence on health have been of interest to dermatologists for >50 years, and an explosion of recent interest in the microbiome has prompted ongoing investigations of several microbial therapeutics for dermatological disease. In this review, we consider how recent insight into the host and microbial factors driving development of the skin microbiome in early life offers new opportunities for therapeutic intervention. IMPACT: Advancement in understanding molecular mechanisms of bacterial competition opens new avenues of investigation into dermatological disease. Primary development of the skin microbiome is determined by immunological features of the cutaneous habitat. Understanding coordinated microbial and immunological development in the pediatric patient requires a multidisciplinary synthesis of primary literature.

Oxytetracycline reduces inflammation and treponeme burden whereas vitamin D3 promotes β-defensin expression in bovine infectious digital dermatitis

Digital dermatitis (DD), a common ulcerative disease of the bovine foot causing lameness and reducing productivity and animal welfare, is associated with infection by spirochete Treponema bacteria. Topical tetracycline, the most common treatment, has inconsistent cure rates; therefore, new therapeutic options are needed. We compared effects of topical oxytetracycline and vitamin D₃ on innate immunity in DD-affected skin. Cows with active DD lesions were treated topically with oxytetracycline or vitamin D₃ and skin biopsies were collected from lesions. Tissue samples were examined histologically, transcriptional expression of pro-inflammatory cytokines, Toll-like receptors (TLRs), and host defense peptides assessed, and the presence of specific treponeme species determined. Effects of treatments at a mechanistic level were studied in a human keratinocyte model of treponeme infection. Oxytetracycline promoted hyperplastic scab formation in ulcerated DD lesions and decreased transcriptional expression of Cxcl-8 (neutrophil chemoattractant). Oxytetracycline also reduced numbers of Treponema phagedenis and T. pedis and enhanced Tlr2 mRNA expression. Vitamin D₃ did not modify expression of cytokines or Tlrs, or bacterial loads, but enhanced transcription of tracheal antimicrobial peptide (Tap), a key bovine β-defensin. Combing oxytetracycline and vitamin D₃ provides complementary clinical benefits in controlling DD through a combination of antimicrobial, immunomodulatory, and pro-healing activities.

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.

Photodynamic therapy inhibit Fibroblast Growth Factor-10 induced keratinocyte differentiation and proliferation through ROS in Fibroblast Growth Factor Receptor-2b pathway

5-aminolevulinic acid-photodynamic therapy (ALA-PDT) is known to be effective in several skin diseases such as acne, actinic keratoses, condyloma acuminata. However, some detailed mechanisms of ALA-PDT to treat these skin diseases still remain elusive. In this study, we aimed to investigate mechanism of ALA-PDT in in-vitro and in-vivo models. For in vitro, we use human keratinocyte cell line (HaCaT) cells. CCK-8 was used to detect cell proliferation activity, immunofluorescence and western blotting method to detect the content of keratin (K)1, K6, K16, protein kinase C (PKC), fibroblast growth factor receptor-2b (FGFR2b) protein, ELISA and RT-PCR to detect expression of interleukin (IL) 1α in the cell supernatant, and detect reactive oxygen species (ROS). For in vivo, we use 20 rabbits to induce hyperkeratosis acne model in their ear. Dermatoscope was used to see follicle hyperkeratosis and skin biopsy to analyze histology and immunohistochemical of PKC, FGFR2b, K1, K6 and K16. Results from this study suggest that ROS stimulated by ALA-PDT lead to inhibition of FGFR2b pathway in PKC downstream to cause reduction of IL1α expression, and eventually, keratinocytes differentiation and proliferation. Our data thus reveal a treatment mechanism of ALA-PDT underlying hyperkeratosis related dermatoses.

Efficacy of tetracyclines in the treatment of acne vulgaris: a review

BACKGROUND

Oral tetracyclines are routinely used for the management of inflammatory acne. However, there is a lack of evidence-based data on their relative effectiveness and appropriate dosages.

OBJECTIVES

To assess the relative effectiveness and the optimal dosage of tetracyclines for the treatment of inflammatory acne.

METHODS

We designed a systematic review of the clinical trials (1962-2006) investigating oral tetracyclines for the treatment of inflammatory acne. We obtained data from MEDLINE, PubMed, Current Contents, reference lists and specialist textbooks.

RESULTS

There was substantial heterogeneity in the design of the trials. We identified only seven randomized trials which were set up to compare the efficacy of tetracyclines in reducing acne lesion counts. These showed no evidence of superiority of one tetracycline over another. Overall, there was also no significant difference between the available tetracyclines in terms of improvement in inflammatory (32 trials, P=0.898) and noninflammatory (23 trials, P=0.429) lesions. In the range of investigated dosages, the antibiotic dosage had no impact on efficacy in inflammatory (P=0.609) and noninflammatory (P=0.654) lesions. There was no decrease in efficacy during the study period.

CONCLUSIONS

There is insufficient evidence to support one tetracycline rather than another in terms of efficacy. In the range of investigated dosages, the antibiotic dosage seems to have no impact on efficacy. Despite increased resistance to antibiotics, oral tetracycline formulations displayed no change in efficacy during the study period. Further studies are, however, required to determine if the anti-inflammatory properties of tetracyclines are sufficient in managing acne.

The tetracyclines in dermatology

Tetracycline is one of the most widely used antibiotics. It may share some properties with conventional immunosuppressive drugs and act as an anti-inflammatory agent in the treatment of inflammatory disease. This article reviews cutaneous diseases that have been treated with tetracyclines and their antiinflammatory and immunosuppressive properties.

The effect of tetracycline and erythromycin in a model of acne-type inflammation

The effects of systemically administered oxytetracycline and erythromycin in a guinea pig model of acne-type inflammation were assessed histologically and by tissue measurement techniques. It was found that oxytetracycline significantly reduced the volume and maximum area of inflammation compared with both control and erythromycin treated groups. Oxytetracycline also altered the morphology of the inflammatory infiltrate significantly reducing the proportion of polymorphonuclear leucocytes present. In this model, erythromycin did not alter the inflammatory response but did seem to reduce the amount of transepidermal elimination of inflammatory debris.

Topical azelaic acid and the treatment of acne: a clinical and laboratory comparison with oral tetracycline

Topical azelaic acid and oral tetracycline were compared in a 6-month double-blind study for treatment of acne vulgaris in 45 male subjects with clinical acne. Their acne was graded, inflamed or non-inflamed, lesions were counted and the density of their skin microflora was measured. Both treatments were of benefit and produced only a few minor side-effects. Although oral tetracycline was more effective than azelaic acid, the differences were only just significant. The average reduction in numbers of cutaneous micrococcaceae and Propionibacterium sp. with azelaic acid treatment was 224 and 30-fold, respectively. In a separate group of 11 male subjects with physiological acne the effect of azelaic acid on sebum excretion rate was assessed, and little change was detected.

Evaluation of a therapeutic strategy for the treatment of acne vulgaris with conventional therapy

Four hundred and twenty patients with moderate to severe acne vulgaris were treated with oral erythromycin and topical benzoyl peroxide to determine the optimum dose regimes. Our results show that the response was significantly less in patients with a greater severity of acne, with truncal acne and in those with a higher sebum excretion rate. There was a significantly better clinical result in patients given Ig erythromycin daily than in those given 0.5 g daily (plus topical therapy in both groups). The relapse rate on stopping antibiotics is also significantly less in patients given I g daily and this dosage did not produce any increase in side effects. We suggest that any patient requiring oral antibiotics should initially be given I g daily of erythromycin (or tetracycline) for up to six months, plus topical therapy.

Effect of clindamycin, erythromycin, lincomycin, and tetracycline on growth and extracellular lipase production by propionibacteria in vitro

Two propionibacteria identified as Propionibacterium acnes and Propionibacterium granulosum were grown anaerobically in the presence of growth subinhibitory concentrations (0.25 and 0.5 minimal inhibitory concentrations) of clindamycin, erythromycin, lincomycin, and tetracycline. Viable counts and assays of extracellular lipase were performed on samples taken at 24-h intervals over a 96-h period. The results showed that lincomycin and clindamycin could inhibit the production of the enzyme by both strains with little effect on their growth rates. Tetracycline caused inhibition of lipase production by P. granulosum only. Although production of the enzyme by P. acnes was delayed in the presence of tetracycline, the final titer was the same as the control. Erythromycin had little effect on growth and enzyme production of either strain. It is possible, therefore, that certain antibiotics used in acne therapy may act not only as bactericidal agents but also as inhibitors of enzyme production under non-growth-limiting conditions.

Acne vulgaris: is the bacterial population size significant?

The levels of Propionibacterium acnes (P. acnes) and members of the Micrococcaceae were enumerated in two separate studies. The first investigation on the foreheads of thirty-five mild and thirty-five moderate acne patients showed no significant difference in the bacterial populations of the two groups. The second investigation of twelve patients on 250 mg tetracycline twice daily for 3 months showed no significant difference compared to pre-treatment data in the bacterial population during the successful treatment period. The data indicate that greater numbers of bacteria are not associated with increasing severity of acne and that the effectivenss of oral tetracycline in treating the disease can not be explained by a reduction in the number of viable bacteria.

A double-blind trial of a zinc sulphate/citrate complex and tetracycline in the treatment of acne vulgaris

Forty-eight patients participated in a 3-month double-blind study to compare the effect of orally administered zinc sulphate/citrate complex and tetracycline hydrochloride in acne vulgaris. Tetracycline significantly reduced the overall grade, and the number of non-inflamed lesions, papules and pustules by the third month. It also reduced significantly the non-inflamed lesions and papules at the end of the second month. In contrast, zinc therapy only had a significant effect on the pustules at the third month. The results indicate that tetracycline is far superior to the zinc complex in patients with moderately severe acne.

The effect of antimicrobial agents on leukocyte chemotaxis

The effects of several chemotherapeutic agents on the chemotaxis of human leukocytes were studied in an in vitro system using a Sykes-Moore chamber and a double-filter technique. Chemotactic factor was generated by the interaction of normal human serum and zymosan. At concentrations comparable to and below therapeutic blood levels, tetracycline HCl, erythromycin base and clindamycin HCl were all inhibitory, causing marked suppression of leukocyte chemotaxis and slight reduction of random migration. Penicillin G-Na, dapsone, and sulfapyridine did not alter white cell motility at the concentrations of drug tested. It is postulated that the capacity of some of these agents to inhibit leukocyte chemotaxis may account, in part, for their efficacy in inflammatory skin diseases such as acne vulgaris.

Panniculitis (Rothmann-Makai), with good response to tetracycline

A case of idiopathic cirucumscribed panniculitis of the legs, with features consistent with that of the Rothmann-Makai syndrome, is reported. The response to a 10-week course of oral tetracycline therapy was impressive. It is suggested that the anti-lipase activity of tetracycline could account for this response.