Antibiotic choice and methicillin-resistant Staphylococcus aureus rate in children hospitalized for atopic dermatitis

Secondary Bacterial Infections in Patients with Atopic Dermatitis or Other Common Dermatoses

Secondary bacterial infections of common dermatoses such as atopic dermatitis, ectoparasitosis, and varicella zoster virus infections are frequent, with Staphylococcus aureus and Streptococcus pyogenes being the bacteria most involved. There are also Gram-negative infections secondary to common dermatoses such as foot dyshidrotic eczema and tinea pedis. Factors favoring secondary bacterial infections in atopic dermatitis, ectoparasitosis, and varicella zoster virus infections mainly include an epidermal barrier alteration as well as itch. Mite-bacteria interaction is also involved in scabies and some environmental factors can promote Gram-negative bacterial infections of the feet. Furthermore, the bacterial ecology of these superinfections may depend on the geographical origin of the patients, especially in ectoparasitosis. Bacterial superinfections can also have different clinical aspects depending on the underlying dermatoses. Subsequently, the choice of class, course, and duration of antibiotic treatment depends on the severity of the infection and the suspected bacteria, primarily targeting S. aureus. Prevention of these secondary bacterial infections depends first and foremost on the management of the underlying skin disorder. At the same time, educating the patient on maintaining good skin hygiene and reporting changes in the primary lesions is crucial. In the case of recurrent secondary infections, decolonization of S. aureus is deemed necessary, particularly in atopic dermatitis.

Bacterial Metabolites and Inflammatory Skin Diseases

The microbiome and gut-skin axis are popular areas of interest in recent years concerning inflammatory skin diseases. While many bacterial species have been associated with commensalism of both the skin and gastrointestinal tract in certain disease states, less is known about specific bacterial metabolites that regulate host pathways and contribute to inflammation. Some of these metabolites include short chain fatty acids, amine, and tryptophan derivatives, and more that when dysregulated, have deleterious effects on cutaneous disease burden. This review aims to summarize the knowledge of wealth surrounding bacterial metabolites of the skin and gut and their role in immune homeostasis in inflammatory skin diseases such as atopic dermatitis, psoriasis, and hidradenitis suppurativa.

Topical Janus kinase inhibitors in atopic dermatitis: a safety network meta-analysis

BACKGROUND

Topical Janus kinase (JAK) inhibitors are being developed for the treatment of mild to moderate atopic dermatitis. However, comparative evidence on their safety profiles is still limited.

AIM

This study aimed to compare the relative safety of topic JAK inhibitors in patients with atopic dermatitis.

METHOD

Phase 2 and 3 clinical trials (RCTs) evaluating the efficacy and safety of topical JAK inhibitors in atopic dermatitis were searched on Medline, EMBASE and clinicaltrials.gov. The following outcomes were considered: any adverse event (AE), serious AEs, AEs leading to treatment discontinuation, any infection, any application site reaction.

RESULTS

Ten RCTs were included in this network meta-analysis. Tofacitinib was associated with a reduced risk of any AE when compared with ruxolitinib (OR 0.18, 95% CrI 0.03-0.92). The analyses for the remaining outcomes did not identify other statistically significant risk differences between the topical JAK inhibitors.

CONCLUSION

Although tofacitinib seems to present a reduced risk of any adverse event compared with ruxolitinib, this was the only statistically significant result found between JAK inhibitors. Therefore, such findings should be interpreted with caution considering the scarce data available and the heterogeneity between the studies, and there is no robust evidence allowing pointing out clinically important differences between the safety profiles of the existing topical JAK inhibitors. Further pharmacovigilance activities are needed to confirm the safety profile of these drugs.

Microbiota and IL-33/31 Axis Linkage: Implications and Therapeutic Perspectives in Atopic Dermatitis and Psoriasis

Microbiome dysbiosis and cytokine alternations are key features of atopic dermatitis (AD) and psoriasis (PsO), two of the most prevalent and burdensome pruritic skin conditions worldwide. Interleukin (IL)-33 and IL-31 have been recognized to be major players who act synergistically in the pathogenesis and maintenance of different chronic inflammatory conditions and pruritic skin disorders, including AD and PsO, and their potential role as therapeutic targets is being thoroughly investigated. The bidirectional interplay between dysbiosis and immunological changes has been extensively studied, but there is still debate regarding which of these two factors is the actual causative culprit behind the aetiopathological process that ultimately leads to AD and PsO. We conducted a literature review on the Pubmed database assessing articles of immunology, dermatology, microbiology and allergology with the aim to strengthen the hypothesis that dysbiosis is at the origin of the IL-33/IL-31 dysregulation that contributes to the pathogenesis of AD and PsO. Finally, we discussed the therapeutic options currently in development for the treatment of these skin conditions targeting IL-31, IL-33 and/or the microbiome.

Skin Antiseptics for Atopic Dermatitis: Dissecting Facts From Fiction

Staphylococcus aureus is a known trigger and cause of infectious complications in atopic dermatitis (AD). Various antiseptics have been used in an attempt to decrease the burden of S. aureus in AD. In this Commentary, we present the evidence for and against some of the commonly used antiseptics in clinical and research settings. These agents remain attractive as an adjunct therapy for AD owing to their relative low cost and potential benefits of reducing S. aureus. Although a number of studies have evaluated the use of dilute bleach, its mechanisms remain controversial. A higher concentration of bleach than the commonly used 0.005% is likely needed for its anti-S. aureus effect. Silver-coated textiles have demonstrated anti-S. aureus effects in various studies; however, their efficacy and side effects in AD remain to be confirmed. Other antiseptics including chlorhexidine, triclosan, and triclocarban are also discussed. Variables that may affect the outcomes of these studies include length of use, concurrent application of moisturizers, and anti-inflammatory medications.

Elevated serum total IgE is associated with eczema exacerbation in children hospitalized for atopic dermatitis

BACKGROUND/OBJECTIVES

Atopic dermatitis (AD) can be a debilitating skin condition, often leading to hospitalization due to severe AD exacerbations or infectious complications. As both AD exacerbations and infectious complications can present similarly, it can be difficult to distinguish the two conditions. Thus, we aimed to evaluate if there is any difference in serum IgE levels in children with AD who were hospitalized for AD exacerbation and for AD-associated infectious complications.

METHODS

A retrospective chart review was performed on hospitalized children with AD exacerbations and AD-associated infectious complications over a 17-year span. Data including length of stay, primary diagnosis, systemic antibiotics, laboratory, and bacterial culture results were collected. Serum total immunoglobulin E (IgE) levels were adjusted by age. Age, length of stay, total IgE levels, and age-adjusted IgE levels were compared using t-test. Logistic regression was used for age-adjusted IgE levels.

RESULTS

The mean serum total IgE level in subjects with AD exacerbation was 9603 ± 15,873 kU/L, which was significantly higher than that of subjects with infectious complications at 3167 ± 5486 kU/L (p = .029). Logistic regression revealed that subjects with an age-adjusted IgE of >4 had more than 3-fold odds of having AD exacerbation than infectious complications.

CONCLUSIONS

Our results suggest that total IgE levels are higher in children who were hospitalized for AD exacerbation than those with AD-associated infectious complications.

Genetic/Environmental Contributions and Immune Dysregulation in Children with Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common skin conditions in humans. AD affects up to 20% of children worldwide and results in morbidity for both patients and their caregivers. The basis of AD is an interplay between genetics and the environment characterized by immune dysregulation. A myriad of mutations that compromise the skin barrier and/or immune function have been linked to AD. Of these, filaggrin gene (FLG) mutations are the most evidenced. Many other mutations have been implicated in isolated studies that are often unreplicated, creating an archive of genes with potential but unconfirmed relevance to AD. Harnessing big data, polygenic risk scores (PRSs) and genome-wide association studies (GWAS) may provide a more practical strategy for identifying the genetic signatures of AD. Epigenetics may also play a role. Staphylococcus aureus is the most evidenced microbial contributor to AD. Cutaneous dysbiosis may result in over-colonization by pathogenic strains and aberrant skin immunity and inflammation. Aeroallergens, air pollution, and climate are other key environmental contributors to AD. The right climate and/or commensals may improve AD for some patients.

Atopic dermatitis: Is innate or adaptive immunity in control? A clinical perspective

Atopic dermatitis (AD) is a chronic inflammatory skin disease with barrier defects and immune dysregulations. The pathogenesis of AD involves the physical barrier as well as epithelial cells, which are considered a vital part of the innate immunity of the skin. The importance of filaggrin mutations in the pathogenesis of AD has also been well-established with reproducible results around the world in multiple studies and ethnic groups. This protein plays an important role in skin barrier functions and further reaffirms barrier defects as one of the primary causes of AD. The main epithelial cells, keratinocytes, function as a major sentinel for the skin in detecting danger signals or microbial pathogens, and trigger downstream immune responses. In AD, these cells express TSLP, IL-33 and IL-25, which lead to downstream systemic production of type 2 cytokines. In spite of major advances in our understanding of the innate immunity of AD, recent success in the systemic therapeutics of AD have focused on targeting the products of the adaptive immunity, particularly cytokines produced by T cells. In addition to type 2 cytokines, type 17 cytokines have also been implicated in the pathogenesis of AD. The current review examines the implications of these cytokines in AD from clinical perspectives.

Complete blood count profiles in children with eczema herpeticum

Eczema herpeticum (EH) can be a life-threatening condition. Prompt diagnosis and treatment are crucial. In this article, we retrospectively assessed the use of screening complete blood count (CBC) to differentiate EH from bacterial skin infection and eczema exacerbation in children who were hospitalized for atopic dermatitis (AD). Children with EH had consistent leukopenia and lymphopenia, relative to the comparison groups as well as standard references.

The infectious complications of atopic dermatitis

OBJECTIVE

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is complicated by an increased risk for skin and systemic infections. Preventive therapy for AD is based on skin barrier improvement and anti-inflammatory treatments, whereas overt skin and systemic infections require antibiotics or antiviral treatments. This review updates the pathophysiology, diagnosis, management, controversy of antibiotic use, and potential treatments of infectious complications of AD.

DATA SOURCES

Published literature obtained through PubMed database searches and clinical pictures.

STUDY SELECTIONS

Studies relevant to the mechanisms, diagnosis, management, and potential therapy of infectious complications of AD.

RESULTS

Skin barrier defects, type 2 inflammation, Staphylococcusaureus colonization, and cutaneous dysbiosis are the major predisposing factors for the increased infections in AD. Although overt infections require antibiotics, the use of antibiotics in AD exacerbation remains controversial.

CONCLUSION

Infectious complications are a comorbidity of AD. Although not common, systemic bacterial infections and eczema herpeticum can be life-threatening. Preventive therapy of infections in AD emphasizes skin barrier improvement and anti-inflammatory therapy. The use of antibiotics in AD exacerbation requires further studies.

Interactions Between Atopic Dermatitis and Staphylococcus aureus Infection: Clinical Implications

Staphylococcus aureus commonly colonizes the skin of atopic dermatitis (AD) patients and contributes to the development and exacerbation of AD. Multiple factors are associated with colonization of AD skin by S. aureus, including the strength of S. aureus-corneocyte adhesion, deficiency of antimicrobial peptides, decreased levels of filaggrin and filaggrin degradation products, overexpressed Th2/Th17 cytokines, microbial dysbiosis and altered lipid profiles. S. aureus colonization on AD skin causes skin barrier dysfunction through virulence factors such as superantigens (toxins), enzymes and other proteins. Furthermore, colonization of AD skin by S. aureus exacerbates AD and may contribute to microbial dysbiosis, allergen sensitization, Th2/Th17 polarization, development of atopic march and food allergy in AD patients. Skin colonization of S. aureus, particularly methicillin-resistant S. aureus (MRSA), is one of the major challenges commonly encountered in the management of AD. Bleach bath, and topical or systemic antibiotics could be used to control S. aureus infection on AD skin. However, careful use of antibiotics is required to control the occurence of MRSA. Recently, various strategies, including microbiome transplant, monoclonal antibodies against virulent toxins, vaccines and recombinant phage endolysin, have been studied to control S. aureus infection on AD skin. Further advances in our understanding of S. aureus could provide us with ways to manage S. aureus colonization more effectively in AD patients.