BackgroundPsoriasis impacts 1–3% of the world’s population and is characterized by hyper-proliferation of keratinocytes and increased inflammation. At the molecular level, psoriasis is commonly driven by a Th17 response, which serves as a major therapeutic target. Microbiome perturbations have been associated with several immune-mediated diseases such as atopic dermatitis, asthma, and multiple sclerosis. Although a few studies have investigated the association between the skin microbiome and psoriasis, conflicting results have been reported plausibly due to the lack of standardized sampling and profiling protocols, or to inherent microbial variability across human subjects and underpowered studies. To better understand the link between the cutaneous microbiota and psoriasis, we conducted an analysis of skin bacterial communities of 28 psoriasis patients and 26 healthy subjects, sampled at six body sites using a standardized protocol and higher sequencing depth compared to previous studies. Mouse studies were employed to examine dermal microbial-immune interactions of bacterial species identified from our study.ResultsSkin microbiome profiling based on sequencing the 16S rRNA V1–V3 variable region revealed significant differences between the psoriasis-associated and healthy skin microbiota. Comparing the overall community structures, psoriasis-associated microbiota displayed higher diversity and more heterogeneity compared to healthy skin bacterial communities. Specific microbial signatures were associated with psoriatic lesional, psoriatic non-lesional, and healthy skin. Specifically, relative enrichment of Staphylococcus aureus was strongly associated with both lesional and non-lesional psoriatic skin. In contrast, Staphylococcus epidermidis and Propionibacterium acnes were underrepresented in psoriatic lesions compared to healthy skin, especially on the arm, gluteal fold, and trunk. Employing a mouse model to further study the impact of cutaneous Staphylcoccus species on the skin T cell differentiation, we found that newborn mice colonized with Staphylococcus aureus demonstrated strong Th17 polarization, whereas mice colonized with Staphylococcus epidermidis or un-colonized controls showed no such response.ConclusionOur results suggest that microbial communities on psoriatic skin is substantially different from those on healthy skin. The psoriatic skin microbiome has increased diversity and reduced stability compared to the healthy skin microbiome. The loss of community stability and decrease in immunoregulatory bacteria such as Staphylococcus epidermidis and Propionibacterium acnes may lead to higher colonization with pathogens such as Staphylococcus aureus, which could exacerbate cutaneous inflammation along the Th17 axis.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0533-1) contains supplementary material, which is available to authorized users.

IMPORTANCE Melanoma in situ (MIS) is increasing in incidence, and expert consensus opinion recommends surgical excision for therapeutic management. Currently, wide local excision (WLE) is the standard of care. However, Mohs micrographic surgery (MMS) is now used to treat a growing subset of individuals with MIS. During MMS, unlike WLE, the entire cutaneous surgical margin is evaluated intraoperatively for tumor cells.OBJECTIVE To assess the outcomes of patients with MIS treated with MMS compared with those treated with WLE. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of a prospective database. The study cohort consisted of 662 patients with MIS treated with MMS or WLE per standard of care in dermatology and surgery (general surgery, otolaryngology, plastics, oculoplastics, surgical oncology) at an academic tertiary care referral center from January 1, 1978, to December 31, 2013, with follow-up through 2015. EXPOSURE Mohs micrographic surgery or WLE. MAIN OUTCOMES AND MEASURES Recurrence, overall survival, and melanoma-specific survival. RESULTS There were 277 patients treated with MMS (mean [SD] age, 64.0 [13.1] years; 62.1% male) and 385 treated with WLE (mean [SD] age, 58.5 [15.6] years; P < .001 for age; 54.8% male). Median follow-up was 8.6 (range, 0.2-37) years. Compared with WLE, MMS was used more frequently on the face (222 [80.2%] vs 141 [36.7%]) and scalp and neck (23 [8.3%] vs 26 [6.8%]; P < .001). The median (range) year of diagnosis was 2008 for the MMS group vs 2003MMS group vs (1978MMS group vs -2013 for the WLE group (P < .001). Overall recurrence rates were 5 (1.8%) in the MMS group and 22 (5.7%) in the WLE group (P = .07). Mean (SD) time to recurrence after MMS was 3.91 (4.4) years, and after WLE, 4.45 (2.7) years (P = .73). The 5-year recurrence rate was 1.1% in the MMS group and 4.1% in the WLE group (P = .07). For WLE-treated tumors, the surgical margin taken was greater for tumors that recurred compared with tumors that did not recur (P = .003). Five-year overall survival for MMS was 92% and for WLE was 94% (P = .28). Melanoma-specific mortality for the MMS group was 2 vs 13 patients for the WLE group, with mean (SD) survival of 6.5 (4.8) and 6.1 (0.8) years, respectively (P = .77).CONCLUSIONS AND RELEVANCE No significant differences were found in the recurrence rate, overall survival, or melanoma-specific survival of patients with MIS treated with MMS compared with WLE.

IntroductionInterleukin (IL)-17 inhibitors are the most recent class of monoclonal antibodies approved by the FDA for psoriasis treatment. Preclinical and phase II studies of brodalumab, a high-affinity IL-17 receptor monoclonal antibody, have been encouraging.MethodsWe conducted a literature search using the PubMed database in order to assess the efficacy and safety profile of brodalumab. The search included the following key words: “psoriasis” and “IL-17” or “brodalumab.” We also reviewed citations within articles to identify relevant sources.ResultsAt week 12, the proportion of patients attaining a 75% improvement from the baseline Psoriasis Area and Severity Index (PASI 75) was similar among the three phase III trials (AMAGINE-1, 83%; AMAGINE-2, 86%; AMAGINE-3, 85%). Brodalumab remained efficacious through 52 weeks of treatment. It maintained a satisfactory safety profile; the most frequently reported adverse events consisted of nasopharyngitis, headache, upper respiratory tract infection, and arthralgia.ConclusionUse of brodalumab revealed prompt clinical improvement and a favorable short-term safety profile in phase III trials, although further extension studies are needed to assess long-term safety. Based on the results, brodalumab appears to be a potent therapeutic option for patients with moderate-to-severe plaque-type psoriasis.

As most efforts in the last decade have focused on the immunologic basis of inflammatory skin disease, there has been less emphasis on the role of the nervous system in the disease process of psoriasis. Evidence in support of the neurocutaneous pathway has come from observations of patients experiencing unilateral improvement and even complete remission following nerve damage in the affected dermatomal region. The aim of this review was to investigate the role of neuropeptides in the intricate pathophysiology of psoriasis. The PubMed database was searched for individual case reports or case series that reported clearance or significant improvement in psoriatic disease in patients following documented nerve injury. A total of 11 cases were found that reported improvement of psoriatic lesions in areas afflicted by central or peripheral nerve injury. The most common causes of denervation were inadvertent surgical interruption, cerebrovascular accident, and poliomyelitis. In four cases the patients eventually regained neurologic function, which was associated with a recurrence of skin lesions. In cases of permanent nerve damage, there was remission of psoriasis. The cases reported in the literature to date provide clinical evidence that absence of neural input leads to psoriasis improvement, suggesting a crucial role of the nervous system in the pathophysiology of psoriatic disease. In fact, neuropeptides such as nerve growth factor, substance P, calcitonin gene-related peptide, and vasoactive intestinal peptide may be important contributors of psoriatic disease and potential targets for future therapies.

IntroductionInterleukin (IL)-23 inhibitors are a new class of biologics currently undergoing clinical trials for the treatment of moderate-to-severe psoriasis. Phase III studies of guselkumab, an IL-23 receptor monoclonal antibody, are currently underway.MethodsWe summarize the available phase III results to date, establishing the efficacy and safety of guselkumab in patients with moderate-to-severe plaque psoriasis.ResultsCurrently, there are available data of up to 48 weeks from two Phase III, multicenter, randomized, double-blind, placebo- and comparator-controlled clinical trials, VOYAGE 1 and VOYAGE 2. At week 16, the proportion of patients attaining at least a 90% improvement from baseline in the Psoriasis Area and Severity Index (PASI 90) was 73.3% in VOYAGE 1 and 70.0% in VOYAGE 2. Guselkumab remained efficacious through 48 weeks of treatment. Guselkumab maintained a satisfactory safety profile with the most frequently reported adverse events being nasopharyngitis, headache, and upper respiratory tract infection.ConclusionPhase III trials of Guselkumab suggest a favorable efficacy and safety profile of this novel drug. Although further studies are needed to assess long-term safety and efficacy, based on the results to date, guselkumab appears to be a promising therapeutic option for moderate-to-severe plaque-type psoriasis.