Dysbiosis and Staphylococcus aureus Colonization Drives Inflammation in Atopic Dermatitis.

Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17(fl/fl)Sox9-(Cre) mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotics specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis.

Clinical presentation and serological diagnosis of syphilis reinfection in men living with HIV: a retrospective cohort study.

OBJECTIVES: Studies on the characteristics of syphilis reinfection are scarce despite increasing numbers and proportions of cases. We aimed to gain insights into the clinical and serological presentation of reinfected men living with HIV and to evaluate diagnostic criteria for syphilis reinfection. METHODS: We conducted a retrospective cohort study of 259 HIV-positive men diagnosed with syphilis between January 1999 and September 2015 at the University Hospital Zurich. We compared patients with a single syphilis infection (n=109) to patients with reinfections (n=150). RESULTS: The two groups matched in age, sexual orientation and numbers of other STIs. Reinfected patients more often presented with latent syphilis than patients with a single syphilis episode (41.9% vs 8.9%; p<0.001). Although generally high venereal diseases research laboratory (VDRL) or rapid plasma reagin (RPR) titres (median 1:32) were seen in reinfected patients, 19.4% had titres ≤1:8. Treponema pallidum passive particle agglutination (TPPA) titres were significantly higher (1:81 840 vs 1:10 240; p<0.001), while IgM values were significantly lower (1.27 vs 3.5; p<0.001) in syphilis reinfections than in first infections. The TPPA increased ≥fourfold in >92.3% of reinfected patients. CONCLUSIONS: Our data highlight the paramount importance of regularly screening patients at risk as syphilis reinfections in men living with HIV are more likely to be latent infections, that is, without symptoms. As non-treponemal tests might be biologically false-positive (up to a titre of 1:8) due to various conditions, a ≥fourfold increase of the TPPA might be considered as optional criterion for the diagnosis of syphilis reinfections. This could be especially valuable for diagnosing reinfected latent stage patients.

IgE-mediated chlorhexidine allergy-Cross-reactivity with other biguanide disinfectants.

BACKGROUND: Chlorhexidine (CHX) is a widely utilized disinfectant that can cause IgE-mediated urticaria/anaphylaxis. The cross-reactivity of patients with IgE-mediated CHX allergy with other disinfectants, which share structural similarities with CHX like polyhexanide (polyhexamethylene biguanide; PHMB), alexidine (ALX), or octenidine (OCT), is unknown. METHODS: Forty-four patients with anaphylaxis or urticaria upon CHX exposure and positive skin prick test (SPT) and/or positive CHX ImmunoCAP test (Phadia TFS, Uppsala, Sweden) were recruited. IgE to the biguanide and/or hexamethylene structure was investigated with PHMB ImmunoCAP (n = 32) and by basophil activation tests (BAT) with CHX and ALX (n = 37). Inhibition tests of CHX and PHMB ImmunoCAPs by CHX, ALX, PHMB, and OCT were performed. RESULTS: IgE reactivity to PHMB as surrogate marker for biguanide/hexamethylene reactivity was detected in 5/32 sera. Seven of 37 patients showed a positive BAT with ALX, but only under optimized conditions. Binding to CHX ImmunoCAP was inhibited by ALX in 1/32 sera, and binding to PHMB was blocked by ALX (1/5) and by OCT in another (1/5). In SPT, 9/10 patients were positive for CHX and 3 of them with ALX (only at highest concentration at 5 mg/mL). A further patient reacted primarily with OCT and showed IgE cross-reactivity with CHX, ALX, and PHMB. CONCLUSION: The IgE response to CHX seems polyclonal. The chloroguanide ending of CHX is the main epitope for the IgE and is suitable as screening assay to detect CHX reactivity. IgE-reactivities with the biguanide or hexamethylene components of other disinfectants (ALX, PHMB) can be detected by SPT, PHMB ImmunoCAP, and ALX-BAT in 15%-33% of CHX-allergic patients.

Optimal Support of Wound Healing: New Insights.

BACKGROUND: The ultimate goal of wound healing following minor injury is to form a tissue regenerate that has functionality and visual appearance as close to the original skin as possible. The body's physiological response to any wound is traditionally characterised by three distinct steps: inflammation, proliferation and remodelling. SUMMARY: New insights suggest that the three phases overlap (and even occur in parallel) in both time and space in the wound, necessitating a clinical approach that targets each stage simultaneously to ensure rapid repair and wound closure without further complications. Ingredients that exhibit activity across each of the three phases, such as dexpanthenol, are of value in the context of minor wound care and scar management. Key Messages: In addition to treatment and ingredient selection, it is also important to consider broader clinical best practices and self-care options that can be used to optimise the management of minor wounds. An individualised approach that can account for a patient's unique requirements and preferences is critical in achieving effective wound recovery.

Antifungal Susceptibility Testing of Malassezia spp. with an Optimized Colorimetric Broth Microdilution Method.

Malassezia is a genus of lipid-dependent yeasts. It is associated with common skin diseases such as pityriasis versicolor and atopic dermatitis and can cause systemic infections in immunocompromised individuals. Owing to the slow growth and lipid requirements of these fastidious yeasts, convenient and reliable antifungal drug susceptibility testing assays for Malassezia spp. are not widely available. Therefore, we optimized a broth microdilution assay for the testing of Malassezia that is based on the CLSI and EUCAST assays for Candida and other yeasts. The addition of ingredients such as lipids and esculin provided a broth medium formulation that enabled the growth of all Malassezia spp. and could be read, with the colorimetric indicator resazurin, by visual and fluorescence readings. We tested the susceptibility of 52 strains of 13 Malassezia species to 11 commonly used antifungals. MIC values determined by visual readings were in good agreement with MIC values determined by fluorescence readings. The lowest MICs were found for the azoles itraconazole, posaconazole, and voriconazole, with MIC90 values of 0.03 to 1.0 µg/ml, 0.06 to 0.5 µg/ml, and 0.03 to 2.0 µg/ml, respectively. All Malassezia spp. were resistant to echinocandins and griseofulvin. Some Malassezia spp. also showed high MIC values for ketoconazole, which is the most widely recommended topical antifungal to treat Malassezia skin infections. In summary, our assay enables the fast and reliable susceptibility testing of Malassezia spp. with a large panel of different antifungals.

Characterization of the early local immune response to Ixodes ricinus tick bites in human skin.

Little is known about the immunomodulation by tick saliva during a natural tick bite in human skin, the site of the tick-host interaction. We examined the expression of chemokines, cytokines and leucocyte markers on the mRNA levels and histopathologic changes in human skin biopsies of tick bites (n=37) compared to unaffected skin (n=9). Early tick-bite skin lesions (<24 hours of tick attachment) were characterized by a predominance of macrophages and dendritic cells, elevated mRNA levels of macrophage chemoattractants (CCL2, CCL3, CCL4) and neutrophil chemoattractants (CXCL1, CXCL8), of the pro-inflammatory cytokine, IL-1ß, and the anti-inflammatory cytokine, IL-5. In contrast, the numbers of lymphocytes and mRNA levels of lymphocyte cell markers (CD4, CD8, CD19), lymphocyte chemoattractants (CXCL9, CXCL10, CXCL11, CXCL13, CCL1, CCL22), dendritic cell chemoattractants (CCL20), and other pro- (IL-6, IL-12p40, IFN-γ, TNF-α) and anti-inflammatory cytokines (IL-4, IL-10, TGF-ß) did not differ from normal skin. With longer tick attachment (>24 hours), the numbers of innate immune cells and mediators (not significantly) declined, whereas the numbers of lymphocytes (not significantly) increased. Natural tick bites by Ixodes ricinus ticks initially elicit a strong local innate immune response in human skin. Beyond 24 hours of tick attachment, this response usually becomes less, perhaps because of immunomodulation by tick saliva.

Skin Test Reactivity to Hymenoptera Venom after Venom Immunotherapy Correlates Inversely with the IgG/IgE Ratio.

BACKGROUND: Skin test reactivity to hymenoptera venom and venom-specific IgE are important for diagnosing venom allergy and deciding on the appropriate allergen for venom immunotherapy (VIT). Longitudinal data on skin test reactivity during VIT and their correlation with venom-specific immunoglobulin (Ig)E and IgG are scarce. METHODS: We retrospectively analyzed shifts in skin test reactivity and serum levels of venom-specific IgE and IgG in patients allergic to hymenoptera venom before the initiation of VIT with ultrarush therapy and after ≥3 years of VIT. RESULTS: Fifty-four patients received ultrarush desensitization and subsequent VIT with wasp venom, 26 with honeybee venom, and 8 with both wasp and honeybee venom. Hymenoptera-specific skin test reactivity decreased during VIT in most patients, and became negative in 8% of the wasp-allergic patients and in 25% of the honeybee-allergic patients. Serum levels of venom-specific IgE positively correlated to skin test reactivity before VIT, but did not change significantly during VIT. IgG serum levels and the IgG/IgE ratio increased during VIT in most patients. A high IgG/IgE ratio correlated with low skin test reactivity after ≥3 years of VIT. CONCLUSIONS: The correlation between a high venom-specific IgG/IgE ratio and low skin test reactivity after VIT may be interesting for future investigations that assess its role as a potential marker for VIT efficacy.

Clinical spectrum of skin manifestations of Lyme borreliosis in 204 children in Austria.

The spectrum of skin manifestations of Lyme borreliosis in children is not well characterized. We conducted a retrospective study to analyze the clinical characteristics, seroreactivity to Borrelia burgdorferi sensu lato, and outcome after treatment in 204 children with skin manifestations of Lyme borreliosis seen in 1996-2011. Solitary erythema migrans was the most common manifestation (44.6%), followed by erythema migrans with multiple lesions (27%), borrelial lymphocytoma (21.6%), and acrodermatitis chronica atrophicans (0.9%). A collision lesion of a primary borrelial lymphocytoma and a surrounding secondary erythema migrans was diagnosed in 5.9% of children. Rate of seroreactivity to B. burgdorferi s.l. was lower in solitary erythema migrans compared to other diagnosis groups. Amoxicillin or phenoxymethylpenicillin led to complete resolution of erythema migrans within a median of 6 (solitary) and 14 days (multiple lesions), respectively, and of borrelia lymphocytoma within a median of 56 days. In conclusion, erythema migrans with multiple lesions and borrelial lymphocytoma appear to be more frequent in children than in adults, whereas acrodermatitis chronica atrophicans is a rarity in childhood. The outcome after antibiotic therapy was excellent in children, and appears to be better than in adults.

Malassezia spp.-specific immunoglobulin E level is a marker for severity of atopic dermatitis in adults.

The significance of allergen-specific IgE as marker for severity of atopic dermatitis is controversial. The aim of this study was to determine the frequency of IgE-mediated sensitisation to food and environmental allergens in 132 children and 67 adults with atopic dermatitis, and its correlation to severity of atopic dermatitis (SCORAD). Total IgE was elevated (> 100 kU/l) in 79.7% of adults and 46.8% of children. Sensitisation frequencies to allergens, particularly microbial allergens, were up to 10-fold higher in adults compared to children. Severity of atopic dermatitis correlated with elevated total IgE in adults (r = 0.549, p < 0.001) and children (r = 0.344, p = 0.005) and with Malassezia spp.-specific IgE in adults (r = 0.429, p = 0.007). Total IgE is a marker for severe atopic dermatitis in both age groups. Malassezia spp.-specific IgE is an important allergen-specific marker for severity of atopic dermatitis in adults.

Phototherapy with UVB narrowband, UVA/UVBnb, and UVA1 differentially impacts serum 25-hydroxyvitamin-D3.

BACKGROUND: Ultraviolet (UV) B radiation increases serum 25-hydroxyvitamin-D3 [25(OH)D], but the influence of UVA1 and UVA/narrowband UVB (UVBnb) phototherapy on serum vitamin D is unknown. OBJECTIVE: We sought to investigate the influence of UVBnb, UVA1, and UVA/UVBnb phototherapy on serum levels of 25(OH)D and related parameters in patients with an inflammatory skin condition. METHODS: 25(OH)D, as well as calcium, parathormone, phosphate, and albumin were measured before therapy, 2 weeks after start, and after completion of the phototherapy. Diagnoses were divided in 4 groups: atopic dermatitis, psoriasis, morphea, and others. RESULTS: We surveyed 116 dermatologic patients undergoing phototherapy with UVA1 (n = 38), UVA/UVBnb (n = 30), or UVBnb (n = 48) 2 to 3 times a week for 53 to 90 days. UVBnb phototherapy increased serum 25(OH)D from 22.1 to 39.5 ng/mL after the therapy (P < .001). The lower the baseline 25(OH)D level was, the steeper the increase in 25(OH)D was upon application of UVBnb phototherapy. UVA/UVBnb therapy also increased serum 25(OH)D, from 23.9 to 50.3 ng/mL (P = .003). Conversely, in the UVA1 therapy group, 25(OH)D serum levels decreased significantly from 21.9 to 19.0 ng/mL (P < .001). LIMITATIONS: The study design was open trial without randomization. An influence of a precise skin disease cannot be excluded because of the heterogeneous diagnoses. Bias may have arisen from patient preference for treatment at our center, referral, unrecognized differences in underlying skin disease, and other factors. CONCLUSION: Phototherapy with UVBnb and UVA/UVBnb increased 25(OH)D serum level significantly. UVA1 therapy alone induced a reduction in serum 25(OH)D concentrations.

Erysipelas of the thigh and the gluteal region: retrospective multicenter analysis of a very rare entity in 39 patients.

BACKGROUND: Erysipelas of the thigh and the gluteal region are rarely described and not well characterized. Therefore we aim to describe the prevalence, clinical characteristics, and risk factors of these erysipelas types. METHODS: The files of 1,423 patients with erysipelas were analyzed. Data from patients with erysipelas of the thigh or the gluteal region were compared between the two groups and with a control group with erysipelas of the lower leg. RESULTS: The thigh was exclusively affected in 2.1%, and the gluteal region in 0.6% of erysipelas patients. Gluteal erysipelas had conspicuous irregular borders and sometimes appeared bilaterally. Major risk factors for erysipelas of both sites were previous surgical interventions. Gluteal erysipelas was common in patients with the metabolic syndrome and required a more intense antibiotic therapy. CONCLUSION: Erysipelas of the thigh and the gluteal region are rare and significantly associated with prior surgical disruption of lymphatic vessels.

Longitudinal Characterization of the Fungal Skin Microbiota in Healthy Subjects Over a Period of 1 Year.

Beneficial microorganisms on the skin contribute to the first line of defense against attacking pathogens. However, instability of the skin microbiota is associated with skin diseases. Hence, temporal analyses are crucial because they serve as a baseline to understand the development of dysbiosis in disease. In this study, we aim to improve the understanding of the fungal skin microbiota, the mycobiota, in healthy subjects. Skin swabs were taken monthly for a year from four different skin sites, that is, antecubital crease, dorsal neck, glabella, and vertex, and analyzed by DNA sequencing of the internal transcribed spacer 1 region. The mycobiota on the skin was dominated by the class Malasseziomycetes, and the core community was composed of Malassezia restricta, M. globosa, and M. sympodialis at all skin sites. Over the period of 1 year, the intrapersonal mycobiota remained largely stable, with some fluctuations of low abundant non-Malassezia fungi. We conclude that despite fluctuations of low abundant classes, fungal skin communities form a temporally robust and individual fingerprint in healthy subjects.

75% negative skin test results in patients with suspected hypersensitivity to beta-lactam antibiotics: Influencing factors and interpretation of test results.

BACKGROUND: The diagnostic approach for beta-lactam (BL) drug hypersensitivity reactions (DHR) is based on the history, clinical signs, skin tests (ST), in vitro tests, and drug provocation tests (DPT). The aim of this study was to assess the performance of an allergy workup with ST in a real-world use. METHODS: In this cross-sectional study the rate of positive ST in subjects with suspected DHR to penicillins and cephalosporins was investigated. Of special interest were correlations of ST positivity: 1) to the time intervals between index reaction and the allergic work-up, 2) time interval from drug exposure to the onset of signs, 3) pattern of manifestation in delayed DHR and involvement of test area in the index reaction, and 4) potential advantage of patch testing in delayed DHR. RESULTS: 175 patients were included between January 2018 and April 2019 (63.4% female), 45 (25.7%) with immediate DHR manifestation and 130 with delayed DHR manifestation (74.3%). A total of 44 patients (25.1%) had a positive ST (immediate DHR 37.8% versus 20.0% in delayed DHR). ST positivity decreased in both groups after 3 years from 47.8% [95%CI 29.2-67] to 23.5% [95%CI 9.6-47.3] in immediate DHR and 23.0% [95%CI 15-4-32.9] to 12.9% [95%CI 5.1-28.9] in delayed DHR. The proportion of positive ST was higher in patients with more severe forms of delayed DHR, and in subjects with a shorter latency period of onset of symptoms after drug exposure: 0-3d: 29.5% [95%CI 19.6-41.9] vs. >3d: 11.6% [95%CI 6.0-21.2]). No sensitization was shown in delayed urticaria or angioedema. ST done outside the skin area involved during the index reaction were negative in all cases (0/38 vs. 26/84 in cases with involved area). The combination of patch test and intradermal test (IDT) revealed an additional positive result in 2/77 cases. Additional in vitro testing reduced the proportion of negative test results to 72%. CONCLUSION: In most patients with negative test results, we could not clarify the cause of the BL-associated adverse events even with further investigations (including DPT). How to prevent new drug-induced adverse events in such patients has hardly been investigated yet. Corresponding cohort studies could improve the data situation.

The emerging role of skin microbiome in atopic dermatitis and its clinical implication.

In recent years, the importance of the microbiome in maintaining healthy skin has become apparent. Both the classic microbiology cultivation techniques used since the early 1970s and the next-generation sequencing procedures refined in the past decade reveal the importance of skin microbiome in healthy and diseased skin. To strengthen and eventually restore a healthy microbiome in patients with dermatological conditions like atopic dermatitis (AD), it is important to consider the factors that influence the composition of the microbiome, such as skin pH and skin barrier integrity. Moreover, targeting the microbiome may support established treatment regimens in years to come. Initial studies have generated promising results, suggesting that AD treatments, including select emollients and topical corticosteroids, have a positive impact on the microbiome. This paper reviews different aspects of microbiome in AD and their implications in clinical practice.

Geographical and Ethnic Differences Influence Culturable Commensal Yeast Diversity on Healthy Skin.

Commensal fungi such as Malassezia, Candida, and Rhodotorula are common on healthy skin but are also associated with opportunistic invasive and superficial infections. Skin microbial community characterization has been extensively performed worldwide, with a focus on the 16S bacterial community. These studies have focused on geographically distinct or targeted cohorts with variable reported species distributions of commensal yeast species. To determine the effects of extrinsic environmental factors such as geography, climate, and ethnicity on detected healthy skin commensal yeast diversity, we compared cohorts from Singapore and Zürich, Switzerland, representative of two geographically and climatically distinct regions comprising multi-ethnic (Chinese, Malay, Indian, Caucasian) and predominantly white Caucasian cohorts, respectively, using identical skin sampling and culture methods. We chose to use a culture-based approach as cultures isolated from patients are still required for studies of pathogenicity and antifungal susceptibility. Detection of yeast species by culture-dependent and independent sequencing-based methods suggest healthy skin diversity reflects a species distribution representative of the geography, climate and ethnic background of their local populations. Culture success and species diversity was also found to be dependent on climate, with warm tropical climates favoring high positive culture rates and greater species diversity. Multilocus sequence typing data suggests some strains are geographically distinct and may be used to segregate potential disease-causing commensals. For accurate collection and characterization of skin microbial communities, it remains recommended to employ a combination of culture-dependent and sequence-based culture-independent methods. Characterization of healthy mycobiomes in geographically distinct local populations will be useful in defining the role of commensal fungi in health and disease.

The Skin Commensal Yeast Malassezia Triggers a Type 17 Response that Coordinates Anti-fungal Immunity and Exacerbates Skin Inflammation.

Commensal fungi of the mammalian skin, such as those of the genus Malassezia, are associated with atopic dermatitis and other common inflammatory skin disorders. Understanding of the causative relationship between fungal commensalism and disease manifestation remains incomplete. By developing a murine epicutaneous infection model, we found Malassezia spp. selectively induce IL-17 and related cytokines. This response is key in preventing fungal overgrowth on the skin, as disruption of the IL-23-IL-17 axis compromises Malassezia-specific cutaneous immunity. Under conditions of impaired skin integrity, mimicking a hallmark of atopic dermatitis, the presence of Malassezia dramatically aggravates cutaneous inflammation, which again was IL-23 and IL-17 dependent. Consistently, we found a CCR6+ Th17 subset of memory T cells to be Malassezia specific in both healthy individuals and atopic dermatitis patients, whereby the latter showed enhanced frequency of these cells. Thus, the Malassezia-induced type 17 response is pivotal in orchestrating antifungal immunity and in actively promoting skin inflammation.

Skin manifestations of lyme borreliosis: diagnosis and management.

Lyme borreliosis is a multisystem infectious disease caused by tick-transmitted spirochetes of the Borrelia burgdorferi sensu lato complex. The three characteristic cutaneous manifestations are erythema migrans, borrelial lymphocytoma, and acrodermatitis chronica atrophicans. Erythema migrans occurs in acute Lyme borreliosis, lymphocytoma is a subacute lesion, and acrodermatitis is the typical manifestation of late Lyme borreliosis. Clinical appearances of erythema migrans and lymphocytoma (when located on the ear or breast) are characteristic, whereas acrodermatitis is often confused with vascular conditions. The diagnosis of erythema migrans is made clinically. Serologic analyses often yield false-negative results and are not required for the diagnosis. However, serologic proof of the diagnosis in lymphocytoma (approximately 90% positive) and acrodermatitis (100% positive) is mandatory. Histopathologic examination often adds substantial information in patients with skin manifestations of Lyme borreliosis and is recommended in clinically (and serologically) undecided cases of erythema migrans or lymphocytoma and is obligatory in acrodermatitis. Polymerase chain reaction for Borrelia-specific DNA (rather than culture of the spirochete) and immunohistochemical investigations (lymphocytoma) are sometimes necessary adjuncts for the diagnosis. Antibacterial treatment is necessary in all patients to eliminate the spirochete, cure current disease, and prevent late sequelae. Oral doxycycline, also effective against coinfection with Anaplasma phagocytophilum, is the mainstay of therapy of cutaneous manifestations of Lyme borreliosis. Other first-line antibacterials are amoxicillin and cefuroxime axetil. Erythema migrans is treated for 2 weeks, lymphocytoma for 3-4 weeks, and acrodermatitis for at least 4 weeks.

Immunoblot analysis of the seroreactivity to recombinant Borrelia burgdorferi sensu lato antigens, including VlsE, in the long-term course of treated patients with erythema migrans.

OBJECTIVE: We evaluated whether immunoblotting is capable of substantiating the posttreatment clinical assessment of patients with erythema migrans (EM), the hallmark of early Lyme borreliosis. METHODS: In 50 patients, seroreactivity to different antigens of Borrelia burgdorferi sensu lato was analyzed by a recombinant immunoblot test (IB) in consecutive serum samples from a minimum follow-up period of 1 year. Antigens in the IgG test were decorin-binding protein A, internal fragment of p41 (p41i), outer surface protein C (OspC), p39, variable major protein-like sequence expressed (VlsE), p58 and p100; those in the IgM test were p41i, OspC and p39. Immune responses were correlated with clinical and treatment-related parameters. RESULTS: Positive IB results were found in 50% before, in 57% directly after therapy and in 44% by the end of the follow-up for the IgG class, and in 36, 43 and 12% for the IgM class. In acute and convalescence phase sera, VlsE was most immunogenic on IgG testing (60 and 70%), and p41i (46 and 57%) and OspC (40 and 57%) for the IgM class. By the end of the follow-up, only the anti-p41i IgM response was significantly decreased to 24%. CONCLUSIONS: No correlation was found between IB results and treatment-related parameters. Thus, immunoblotting does not add to the clinical assessment of EM patients after treatment.