Gram-negative folliculitis--a complication of antibiotic therapy in acne vulgaris

The Bacteriology of Skin Lesions in Patients with Hidradenitis Suppurativa Is Associated with Previous Antibiotic Treatment in the Community Setting: A Referral Center Experience

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic skin disease characterized by inflammatory nodules and abscesses. The pathogenic role of bacteria is not fully understood. As the diagnosis is usually delayed, patients are often treated with several lines of antibiotics in a nonstandardized fashion. The aim of the study was to investigate and compare the bacteriology of active HS lesions in patients treated or not treated with antibiotics in the community setting before referral to a dedicated HS clinic.

METHODS

Purulent skin lesions of patients with HS referred to the HS Clinic of Rabin Medical Center in 2009-2020 were cultured. Data were collected from the patients' medical files and microbiology reports. The correlation between the location of the skin lesion and the bacteriologic profile was analyzed, and the effects of previous antibiotic treatment on the bacteriologic profile of the lesions and susceptibility patterns of the cultured bacteria were evaluated.

RESULTS

Pus (or tissue) from inflammatory lesions of 97 patients with HS was cultured. Mean (SD) patient age was 39.5 (13.0) years, and mean delay in diagnosis was 7.3 (8.3) years. Most patients (57.7%) had dominant involvement of one location, with the most active lesions concentrated in the genitalia, gluteal/perineal area, and axilla. Enterobacterales species were the most frequent isolates detected in all locations except the face and scalp. Seventy-eight patients (80.4%) had been treated in the community setting prior to referral with a median (range) of 2 (1-8) lines of antibiotics. The most commonly prescribed antibiotics were amoxicillin/clavulanate (22.0%), doxycycline/minocycline (16.8%), clindamycin (16.2%; monotherapy 8.1%, clindamycin with rifampicin 8.1%), and cephalexin (13.9%). Compared to the previously untreated patients, cultures of lesions from the previously treated patients yielded a higher percentage of gram-negative Enterobacterales (the most common isolates in this group) (31.3% vs. 10.3%) and a significantly higher median number of isolates per culture (2 vs. 1, p < 0.0001). Gram-positive bacteria, usually considered contaminants (mainly coagulase-negative staphylococci) accounted for 31.0% of the isolates in the previously treated group. Susceptibility testing for the entire cohort revealed 100% bacterial sensitivity to ciprofloxacin. Staphylococcus spp. were 100% sensitive to rifampicin. Both gram-positive and gram-negative bacteria had high sensitivity to trimethoprim and sulfamethoxazole.

CONCLUSION

Nonstandardized antibiotic treatment of HS in the community setting can skew the microbiology of skin lesions toward gram-negative bacteria. Therefore, treatment with trimethoprim and sulfamethoxazole or ciprofloxacin, either alone or combined with rifampicin, may be considered.

Association of Systemic Antibiotic Treatment of Acne With Skin Microbiota Characteristics

Importance

Given the widespread use of systemic antibiotics for treatment of moderate to severe acne, it is important to understand the associations of such antibiotic use with changes not only in Cutibacterium acnes (formerly Propionibacterium acnes) but also in the complete bacterial community of the skin.

Objective

To examine the composition, diversity, and resilience of skin microbiota associated with systemic antibiotic perturbation in individuals with acne.

Design, Setting, and Participants

This longitudinal cohort study conducted at an academic referral center in Maryland from February 11 to September 23, 2014, included 4 female participants who had received a recent diagnosis of acne vulgaris, showed comedonal and inflammatory acne on the face, were at least 18 years old, and had no recent use of systemic or topical treatments for acne, including antibiotics and retinoids. Data analysis was performed between July 5, 2017, and November 7, 2018.

Interventions

Participants were prescribed oral minocycline, 100 mg, twice daily for 4 weeks. Skin areas on the forehead, cheek, and chin were sampled for 16S ribosomal RNA gene sequencing at baseline, 4 weeks after starting minocycline treatment, and then 1 week and 8 weeks after discontinuation of treatment.

Main Outcomes and Measures

Skin microbiota examined with respect to relative abundance of bacterial taxa, α diversity (represents within-sample microbial diversity), and β diversity (represents between-sample microbial diversity). Acne status evaluated with photography and lesion count.

Results

Of the 4 patients included in this study, 2 were 25 years old, 1 was 29 years old, and 1 was 35 years old; 2 were white women, 1 was an African American woman, and 1 was an Asian woman. Across all 4 patients, antibiotic treatment was associated with a 1.4-fold reduction in the level of C acnes (difference, -10.3%; 95% CI, -19.9% to -0.7%; P = .04) with recovery following cessation of treatment. Distinct patterns of change were identified in multiple bacterial genera, including a transient 5.6-fold increase in the relative abundance of Pseudomonas species (difference, 2.2%; 95% CI, 0.9%-3.4%; P < .001) immediately following antibiotic treatment, as well as a persistent 1.7-fold increase in the relative abundance of Streptococcus species (difference, 5.4%; 95% CI, 0.3%-10.6%; P = .04) and a 4.7-fold decrease in the relative abundance of Lactobacillus species (difference, -0.8%; 95% CI, -1.4% to -0.2%; P = .02) 8 weeks following antibiotic treatment withdrawal. In general, antibiotic administration was associated with an initial decrease from baseline of bacterial diversity followed by recovery. Principal coordinates analysis results showed moderate clustering of samples by patient (analysis of similarity, R = 0.424; P = .001) and significant clustering of samples by time in one participant (analysis of similarity, R = 0.733; P = .001).

Conclusions and Relevance

In this study, systemic antibiotic treatment of acne was associated with changes in the composition and diversity of skin microbiota, with variable rates of recovery across individual patients and parallel changes in specific bacterial populations. Understanding the association between systemic antibiotic use and skin microbiota may help clinicians decrease the likelihood of skin comorbidities related to microbial dysbiosis.

Bedside diagnostics in dermatology: Viral, bacterial, and fungal infections

Viral, bacterial, and fungal infections are frequently encountered in clinical practice, resulting in numerous cutaneous manifestations. Although diagnosis of these infections has changed over time because of technological advancements, such as polymerase chain reaction, bedside diagnostic techniques still play an important role in diagnosis and management, enabling rapid and low-cost diagnosis and implementation of appropriate therapies. This 2-part article will review both common and infrequent uses of bedside diagnostic techniques that dermatologists can incorporate into daily practice. This article examines the utility of bedside tests for the diagnosis of viral, bacterial, and fungal infections. The second article in this series reviews the use of bedside diagnostics for parasitic and noninfectious disorders.

Optimizing Non-Antibiotic Treatments for Patients with Acne: A Review

Acne is a very common non-infectious skin condition that is frequently treated in dermatological practices. Because acne is often chronic and may persist for years, safe and effective long-term maintenance therapy is often required. Given the increasing frequency of antibiotic-resistant bacteria and the gravity of the consequences of this trend, it behooves dermatologists to maximize use of non-antimicrobial therapy when treating acne. In this review of the literature we present data regarding the efficacy and appropriate use of non-antimicrobial treatments for acne. A variety of topical and oral treatment options exist that can be used in a step-wise manner according to the patients’ severity and therapeutic response. Non-antimicrobial treatments can be highly efficacious at controlling acne, especially when used as maintenance therapy. While antibiotics have a role in acne treatment, they should not be used as monotherapy, and lengthy courses of antibiotic use are discouraged.

The intersection of microbiome and host at the skin interface: genomic- and metagenomic-based insights

The past two decades have been marked by a surge in research to understand the microbial communities that live in association with the human body, in part stimulated by affordable, high-throughput DNA sequencing technology. In the context of the skin, this Perspective focuses on the current state of genomic- and metagenomic-based host–microbe research and future challenges and opportunities to move the field forward. These include elucidating nonbacterial components of the skin microbiome (i.e., viruses); systematic studies to address common perturbations to the skin microbiome (e.g., antimicrobial drugs, topical cosmetic/hygienic products); improved approaches for identifying potential microbial triggers for skin diseases, including species- and strain-level resolution; and improved, clinically relevant models for studying the functional and mechanistic roles of the skin microbiome. In the next 20 years, we can realistically expect that our knowledge of the skin microbiome will inform the clinical management and treatment of skin disorders through diagnostic tests to stratify patient subsets and predict best treatment modality and outcomes and through treatment strategies such as targeted manipulation or reconstitution of microbial communities.

Top Ten List of Clinical Pearls in the Treatment of Acne Vulgaris

Acne represents the most common inflammatory dermatosis seen worldwide and is the leading reason for seeing a dermatologist. This article provides some tips for managing acne in a safe and effective manner to minimize the physical and psychological scars that can result from acne. Tips include how to optimize available treatment regimens according to the evidence base and target therapy to pathophysiologic factors, while also tailoring treatments to patient expectation and needs. Attention is given to minimizing the emergence of antimicrobial resistance in acne patients and beyond.

Perioral lesions and dermatoses

The purpose of this article is to review the common neoplasms, infections, and inflammatory dermatoses that may present around or near the mouth. Dental professionals are well positioned to evaluate perioral skin conditions, further contributing to patients' general health. This article includes a review of seborrheic keratosis, warts, actinic keratoses, actinic cheilitis, and squamous cell carcinoma, among several other perioral cutaneous lesions.

In vitro antibacterial activity of NB-003 against Propionibacterium acnes

NB-003 and NB-003 gel formulations are oil-in-water nanoemulsions designed for use in bacterial infections. In vitro susceptibility of Propionibacterium acnes to NB-003 formulations and comparator drugs was evaluated. Both NB-003 formulations were bactericidal against all P. acnes isolates, including those that were erythromycin, clindamycin, and/or tetracycline resistant. In the absence of sebum, the MIC(90)s/minimum bactericidal concentrations (MBC(90)s) for NB-003, NB-003 gel, salicylic acid (SA), and benzoyl peroxide (BPO) were 0.5/2.0, 1.0/2.0, 1,000/2,000, and 50/200 μg/ml, respectively. In the presence of 50% sebum, the MIC(90)s/MBC(90)s of NB003 and BPOs increased to 128/1,024 and 400/1,600 μg/ml, respectively. The MIC(90)s/MBC(90)s of SA were not significantly impacted by the presence of sebum. A reduction in the MBC(90)s for NB-003 and BPO was observed when 2% SA or 0.5% BPO was integrated into the formulation, resulting in MIC(90)s/MBC(90)s of 128/256 μg/ml for NB003 and 214/428 μg/ml for BPO. The addition of EDTA enhanced the in vitro efficacy of 0.5% NB-003 in the presence or absence of 25% sebum. The addition of 5 mM EDTA to each well of the microtiter plate resulted in a >16- and >256-fold decrease in MIC(90) and MBC(90), yielding a more potent MIC(90)/MBC(90) of ≤1/<1 μg/ml. The kinetics of bactericidal activity of NB-003 against P. acnes were compared to those of a commercially available product of BPO. Electron micrographs of P. acnes treated with NB-003 showed complete disruption of bacteria. Assessment of spontaneous resistance of P. acnes revealed no stably resistant mutant strains.

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.

Clinical considerations in the treatment of acne vulgaris and other inflammatory skin disorders: a status report

This article reviews the anti-inflammatory and nonantimicrobial effects of antibiotics in acne and other diseases and examines issues relating to the emergence of decreased bacterial sensitivity to antibiotics and how these issues relate to clinical practice. It includes an overview of the inflammatory activities of some antibiotic agents and their potential for use in various dermatologic and nondermatologic diseases. It demonstrates that P. acnes-resistant organisms may be associated with therapeutic failure in some patients with acne, and that the prudent use of antibiotics is necessary to ensure that we can continue to use these drugs to combat disease effectively. It concludes that there are treatment strategies that can effectively minimize the potential for development of resistant P. acnes organisms.

A single-blinded, randomized, controlled clinical trial evaluating the effect of face washing on acne vulgaris

Despite the common recommendation to wash the face twice daily with a mild cleanser, there is little published evidence to support the practice. Indeed, while the general public believes that cleaner skin will result in fewer blemishes, dermatologists often warn that overwashing and scrubbing can exacerbate the condition. To clarify the effect of frequency of face washing on acne vulgaris, we designed a single-blinded, randomized, controlled clinical trial to be conducted on males with mild to moderate acne vulgaris. Subjects washed their faces twice daily for 2 weeks with a standard mild cleanser before being randomized to one of three study arms, in which face washing was to be done once, twice, or four times a day for 6 weeks. At the end of the study no statistically significant differences were noted between groups. However, significant improvements in both open comedones and total noninflammatory lesions were observed in the group washing twice a day. Worsening of acne condition was observed in the study group washing once a day, with significant increases in erythema, papules, and total inflammatory lesions. We concluded that slight support exists, both in terms of efficacy and convenience, for the recommendation to wash the face twice daily with a mild cleanser. However, excessive face washing may not be as culpable as previously thought.

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 gram-negative folliculitis in patients with acne

Gram-negative folliculitis may be the result of long-term antibacterial treatment in acne patients. It is caused by bacterial interference and replacement of the Gram-positive flora of the facial skin and the mucous membranes of the nose and infestation with Gram-negative bacteria. These Gram-negative bacteria include Escherischia coli, Pseudomonas aeruginosa, Serratia marescens, Klebsiella and Proteus mirabilis. The occurrence of Gram-negative folliculitis should be considered in acne patients in whom oral treatment with tetracyclines has not resulted in a significant improvement of acne lesions after 3-6 months' treatment. The occurrence of Gram-negative folliculitis in acne patients is believed to be generally underestimated, since correct sampling and bacteriology is rarely performed by clinicians. Gram-negative folliculitis in acne and rosacea patients is best treated with isotretinoin (0.5-1 mg/kg daily for 4-5 months).

Cosmetics: what is their influence on the skin microflora?

Human skin has a resident, transient and temporary resident microflora. This article considers the possibilities of topical products influencing the balance of the microflora. The resident micro-organisms are in a dynamic equilibrium with the host tissue and the microflora may be considered an integral component of the normal human skin. The great majority of these micro-organisms are gram-positive and reside on the skin surface and in the follicles. The host has a variety of structures, molecules and mechanisms which restrict the transient and temporary residents, as well as controlling the population and dominance of the resident group. These include local skin anatomy, hydration, nutrients and inhibitors of various types. The resident microflora is beneficial in occupying a niche and denying its access to transients, which may be harmful and infectious. Also, the residents are important in modifying the immune system. In the healthy host the microflora causes few and temporary problems. Therefore, it is of interest that topical products have little or no effect on the ecology of the microflora. A range of mechanisms by which long-term use of cosmetics may influence the microflora are considered. Although the risks associated are low, it is argued that it is necessary to monitor these changes in ecology and use technologies of modeling and bioinformatics to predict outcomes, whether good, neutral or of concern.

Bacteriologic and immunologic aspects of gram-negative folliculitis: a study of 46 patients

BACKGROUND

Gram-negative folliculitis is an infection with gram-negative rods that most often occurs as a complication of prolonged broad-spectrum antibiotic therapy in patients suffering from acne and rosacea.

METHODS

The bacteriologic and immunologic findings are reported in 46 patients, 39 men and 7 women, aged 16-79 (median, 28) years, with gram-negative folliculitis. Hypersensitivity reactions to various microbial recall antigens as well as granulocyte functions were evaluated. Quantitative measurements of serum levels of immunoglobulin M, G, A, and E, total complement activity, complement factors C3 and C4, and alpha-1-antitrypsin were performed.

RESULTS

The gram-negative organisms most frequently cultivated from nares, facial skin, and pustules were Klebsiella spp., Escherichia coli, Enterobacter spp., and Proteus spp. In all patients, deviations of one or more immune parameters were detected, including lowered serum concentrations of immunoglobulin M and alpha-1-antitrypsin, and elevated levels of immunoglobulin E. The humoral and cellular parameters were not influenced by isotretinoin therapy of gram-negative folliculitis.

CONCLUSIONS

These findings suggest that gram-negative folliculitis is not only a complication of long-lasting antibiotic treatment of acne and rosacea, but might be an entity of its own. Immunologic factors may play a critical role in the pathogenesis of gram-negative folliculitis.

Recurrent Pseudomonas folliculitis

Pseudomonas aeruginosa has attracted the attention of the dermatologic literature through repeatedly reported outbreaks of folliculitis occurring in small epidemics related to contaminated whirlpools, hot tubs, and swimming pools. In contrast, sporadic cases without these recreational exposures may present a diagnostic challenge. Two sisters, age 8 and 4 years, had sporadic Pseudomonas folliculitis. It is important to recognize the organism as the cause of this recurrent, papulopustular, follicular eruption on the trunk and gluteal regions, also called nonrecreational Pseudomonas folliculitis, to avoid misdiagnosis and mismanagment. Inadvertent therapy with steroids may result in rapid spread of the lesions. Unless a meticulous investigation of contaminant sources in the environment leads to the detection of the vehicle of infection, the dermatitis tends to recur and become chronic.

Guidelines for optimal use of isotretinoin in acne

Isotretinoin is most effective for patients with acne who fail to respond to other forms of treatment; virtually all patients respond to isotretinoin, 0.5 to 1.0 mg/kg/day. As many as 61% of patients are cured after one course, but 39% require further isotretinoin (16%) or oral antibiotics (23%). The relapse rate can be reduced by the administration of the higher dose of 1 mg/kg/day (thus achieving a significant cumulative dose of > 120 mg/kg), especially to young patients and men with truncal acne and more severe disease. About 85% require a 4-month course, but 15% require longer treatment, with some up to 10 months. There are several reasons for a slow response to treatment, including the presence of macrocomedones, ovarian dysfunction, and as-yet unknown factors. Macrocomedones can be treated with light cautery, ovarian dysfunction with hormonal therapies, and in those persons who have no obvious explanation for slow response, persistence with isotretinoin alone is required. Repeat courses of isotretinoin can also be given. Six years ago most patients treated with isotretinoin had severe acne (60%), but today most patients (60%) have therapy-resistant moderate acne. Isotretinoin is a consideration in such patients to reduce the physical and psychological effects of acne, particularly because there is no simple method to treat acne scars.

Microbiology of the skin: resident flora, ecology, infection

Humans exist in an environment replete with microorganisms, but only a few become resident on the skin surface. The skin possesses protective mechanisms to limit colonization, and the survival of organisms on the surface lies in part in the ability of the organisms to resist these mechanisms. Microbial colonization on the skin adds to the skin's defense against potentially pathogenic organisms. Although microbes normally live in synergy with their hosts, occasionally colonization can result in clinical infection. Common infections consist of superficial infections of the stratum corneum or appendageal structures that can respond dramatically to therapy but commonly relapse. In rare circumstances, these infections can be quite severe, particularly in immunocompromised patients or in hospitalized patients with indwelling foreign devices. These infections are often resistant to conventional antibiotics and can result in infection with other opportunistic pathogens.

Organisms associated with gram-negative folliculitis: in vitro growth in the presence of isotretinoin

Isotretinoin has been found to be effective in the treatment of Gram-negative folliculitis. We investigated the direct in vitro antibacterial activity of isotretinoin against Gram-negative species. The concentrations of isotretinoin tested were two and ten times greater than the maximal levels attained in the sera of patients receiving oral isotretinoin. Regardless of the inoculum size, each organism tested grew as well in isotretinoin-containing media as it did in the control medium. These findings suggest that the efficacy of isotretinoin in patients with Gram-negative folliculitis is due to mechanisms other than direct antimicrobial action.

Treatment of gram-negative folliculitis with isotretinoin

The clinical and bacteriological findings are reported in 13 patients with gram-negative folliculitis before, during, and after treatment with isotretinoin (13-cis-retinoic acid). Patients were treated for 14-36 weeks with a daily dose of 0.5-1.5 mg isotretinoin/kg body weight. Inflammatory lesions were counted before and during weeks 2, 4, 8, 12, 16, 20, 24, 28, and 30 of therapy and again up to 172 weeks after cessation of treatment. In all patients there was an impressive improvement in clinical symptoms, especially a decrease in seborrhea and inflammatory lesions. Simultaneously, the gram-negative bacteria disappeared from the facial skin. Full clinical bacteriological remission was achieved in 9 patients within a period of up to 43 months, with minor recurrences of the disease in the remaining 4 patients.

Pustular acne

Pustules from 92 new cases of pustular acne and gram-negative folliculitis were cultured in aerobic medium for superimposed bacterial infection. During the treatment of 1,561 new patients with papular acne with tetracycline and topical clindamycin and antibacterial soaps, an additional 10 developed pustules. The majority showed in vitro resistance to ampicillin. The effective treatment was co-trimoxazole and topical gentamicin. A new classification of acne with practical therapeutic use is needed.

Treatment of gram-negative folliculitis with isotretinoin: positive clinical and microbiologic response

Thirty-two patients with gram-negative folliculitis were treated with 0.47 to 1.0 mg/kg/day of isotretinoin. Serial microbiologic evaluations demonstrated rapid clearing of the face and nasal mucosa of gram-negative rods. The clinical response was rapid, complete, and induced prolonged remissions. Twenty-six of thirty-two patients developed Staphylococcus aureus nasal carriage by the end of the 20-week treatment course. Isotretinoin has decided advantages over previously reported therapies for gram-negative folliculitis.

Therapy of acne

Today acne vulgaris is a disease which can be well controlled using a combination of topical, systemic, and physical therapeutic modalities. However, successful acne management depends to a large extent on physician interest and the ability of the physician to apply therapy to the evolutionary stage of the disease and to the disturbed pathogenetic mechanisms. It is this author's opinion that grades I and II comedonal and papulopustular acne can be effectively treated solely with topical preparations, particularly the concurrent use of tretinoin with benzoyl peroxide or topical antibiotics. The majority of patients with grades III and IV inflammatory disease require oral antibiotics in addition to aggressive topical treatments. Intralesional steroids can be effective in all grades of acne when lesions develop an inflammatory nodulocystic quality. The physician should consider the use of estrogen (in females) or oral vitamin A in the small group of patients with grades III and IV inflammatory-cystic acne that has been unresponsive to conventional therapy. Combined systemic therapies of high-dose antibiotics, systemic corticosteroids, and sulfones clearly take precedence over topical preparations in conglobate acne and acne fulminans. Finally, oral isotretinoin, alone and perhaps in combination with more conventional modalities, should play an important role in the future management of severe inflammatory-cystic acne.

Action of isotretinoin in acne rosacea and gram-negative folliculitis

Good to excellent clinical results have been obtained in the treatment of severe inflammatory acne (acne conglobata, acne fulminans, and acne conglobata with hidradenitis and dissecting cellulitis of the scalp) with orally administered isotretinoin (13-cis-retinoic acid). Similar promising results have been obtained in patients with severe rosacea and gram-negative folliculitis. Isotretinoin probably has multiple modes of action, including (1) inhibition of sebaceous gland activity, (2) inhibition of the growth of Propionibacterium acnes within the follicle, although the retinoid is not antibacterial, (3) inhibition of inflammation, and (4) alteration of the pattern of keratinization within the follicle, as demonstrated by light and ultrastructural studies.

Pyoderma faciale: a clinical study of twenty-nine patients

Pyoderma faciale is a distinctive entity. Twenty-nine patients with this process were seen in the Mayo Clinic from 1969 to 1980. Twenty-seven patients had follow-up that ranged from 1 month to 11 years, and twenty-two had follow-up of 3 years or more. Clinical features that characterize the patients were (1) female predominance, (2) onset later than teenage acne vulgaris, generally at 19 to 40 years of age, (3) rapid onset and progression, (4) facial involvement with sparing of the back and chest, (5) cysts, swelling, and purulent drainage with a lack of comedones, and (6) paucity of systemic complaints. Patients were treated with multiple forms of therapy simultaneously, often including Vleminckx packs, oral antibiotics, incision and drainage, ultraviolet B, and intralesional steroids. Of twenty-five patients available for follow-up at 1 year, twenty-three had achieved remission, though fifteen patients required ongoing treatment to maintain optimal control. Twenty-three patients had scarring as a sequela. Patients with pyoderma faciale represent a subset of patients with acne in whom the outlook is favorable with appropriate therapy.