Skin Microbiome in Prurigo Nodularis.

Prurigo nodularis (PN) is a chronic condition characterized by the presence of nodular lesions accompanied by intense pruritus. The disease has been linked to several infectious factors, but data on the direct presence of microorganisms in the lesions of PN are scarce. The aim of this study was to evaluate the diversity and composition of the bacterial microbiome in PN lesions by targeting the region V3-V4 of 16S rRNA. Skin swabs were obtained from active nodules in 24 patients with PN, inflammatory patches of 14 patients with atopic dermatitis (AD) and corresponding skin areas of 9 healthy volunteers (HV). After DNA extraction, the V3-V4 region of the bacterial 16S rRNA gene was amplified. Sequencing was performed using the Illumina platform on the MiSeq instrument. Operational taxonomic units (OTU) were identified. The identification of taxa was carried out using the Silva v.138 database. There was no statistically significant difference in the alpha-diversity (intra-sample diversity) between the PN, AD and HV groups. The beta-diversity (inter-sample diversity) showed statistically significant differences between the three groups on a global level and in paired analyses. Staphylococcus was significantly more abundant in samples from PN and AD patients than in controls. The difference was maintained across all taxonomic levels. The PN microbiome is highly similar to that of AD. It remains unclear whether the disturbed composition of the microbiome and the domination of Staphylococcus in PN lesions may be the trigger factor of pruritus and lead to the development of cutaneous changes or is a secondary phenomenon. Our preliminary results support the theory that the composition of the skin microbiome in PN is altered and justify further research on the role of the microbiome in this debilitating condition.

Diversity and Composition of the Skin, Blood and Gut Microbiome in Rosacea-A Systematic Review of the Literature.

Rosacea is a chronic inflammatory skin disorder of a not fully understood pathophysiology. Microbial factors, although not precisely characterized, are speculated to contribute to the development of the condition. The aim of the current review was to summarize the rosacea-associated alterations in the skin, blood, and gut microbiome, investigated using culture-independent, metagenomic techniques. A systematic review of the PubMed, Web of Science, and Scopus databases was performed, according to PRISMA (preferred reporting items for systematic review and meta-analyses) guidelines. Nine out of 185 papers were eligible for analysis. Skin microbiome was investigated in six studies, and in a total number of 115 rosacea patients. Blood microbiome was the subject of one piece of research, conducted in 10 patients with rosacea, and gut microbiome was studied in two papers, and in a total of 23 rosacea subjects. Although all of the studies showed significant alterations in the composition of the skin, blood, or gut microbiome in rosacea, the results were highly inconsistent, or even, in some cases, contradictory. Major limitations included the low number of participants, and different study populations (mainly Asians). Further studies are needed in order to reliably analyze the composition of microbiota in rosacea, and the potential application of microbiome modifications for the treatment of this dermatosis.

Mepolizumab Therapy for Recalcitrant Eosinophilic Annular Erythema in an Adult: A Case Report and Review of Treatment Options.

Eosinophilic annular erythema (EAE) is a rare condition with a chronic relapsing and remitting course, characterized by the presence of annular or polycyclic erythematous and plaque lesions and prominent tissue eosinophilia on histopathology. There is an ongoing discussion on whether EAE is a subset of Wells syndrome (eosinophilic cellulitis) or a separate entity. To date, few cases of EAE have been reported in the literature; of these, about 40 cases were in adults and fewer than ten cases were in children. Given the rarity of this condition, there are no clear recommendations for its management. Systemic corticosteroids and antimalarials are the most commonly used medications used to treat EAE, but many cases have been reported in the literature that are resistant to treatment with these medications. Here, we present a 65-year-old female with EAE refractory to numerous systemic therapies (corticosteroids, hydroxychloroquine, dapsone, doxycycline, methotrexate) who showed a good response to mepolizumab, a humanized monoclonal antibody that blocks interleukin-5. To the best of our knowledge, this is the first reported case of mepolizumab therapy in a patient with EAE. We also review other treatment strategies that have been used to manage this condition to date. Targeting cytokines crucial for the functioning of eosinophils may be a novel direction in the management of EAE, but prospective, double-blinded and placebo-controlled studies are needed to provide further evidence.