Is Scleroderma Pattern Able to Address a Specific Diagnosis of Connective Tissue Diseases?

Introduction: Nailfold videocapillaroscopy (NVC) is a non-invasive imaging technique widely used to investigate microvascular abnormalities in different connective tissue diseases (CTDs). Methods: We conducted a retrospective study where we analysed 415 patients submitted to NVC. Patients with scleroderma-like pattern were selected to investigate if there are specific NCV changes, which discriminate among the different CTDs. Ninety-one patients met this requirement and had a diagnosis of CTD. For each patient the following abnormalities were observed: enlarged and giant capillaries, oedema, loss and rarefaction of capillaries, long loops and minor dystrophies. Results: Multivariate analyses did not reveal any specific modification among the analysed co-variables for scleroderma (SS) and dermatomyositis (DM). For the others CTDs analysed in this study, logistic regression revealed that some of the capilloroscopic features could be indicative of specific diseases. Of note, the presence of megacapillaries with long loops in a scleroderma-like pattern seems to be highly indicative for a diagnosis of systemic lupus erythaematosus (SLE). Conclusions: Our data showed that in CTDs with a scleroderma-like pattern, the NVC variables alone are not able to discriminate for a specific diagnosis of CTD. Ne

Seborrheic dermatitis—Looking beyond Malassezia

Seborrhoeic Dermatitis (SD) is a very common chronic and/or relapsing inflammatory skin disorder whose pathophysiology remains poorly understood. Yeast of the genus Malassezia has long been regarded as a main predisposing factor, even though causal relationship has not been firmly established. Additional predisposing factors have been described, including sebaceous activity, host immunity (especially HIV infection), epidermal barrier integrity, skin microbiota, endocrine and neurologic factors, and environmental influences. Genetic studies in humans and mouse models-with particularly interesting insights from examining the Mpzl3 knockout mice and their SD-like skin phenotype, and patients carrying a ZNF750 mutation-highlight defects in host immunity, epidermal barrier and sebaceous activity. After synthesizing key evidence from the literature, we propose that intrinsic host factors, such as changes in the amount or composition of sebum and/or defective epidermal barrier, rather than Malassezia, may form the basis of SD pathobiology. We argue that these intrinsic changes provide favourable conditions for the commensal Malassezia to over-colonize and elicit host inflammatory response. Aberrant host immune activity or failure to clear skin microbes may bypass the initial epidermal or sebaceous abnormalities. We delineate specific future clinical investigations, complemented by studies in suitable SD animal models, that dissect the roles of different epidermal compartments and immune components as well as their crosstalk and interactions with the skin microbiota during the process of SD. This research perspective beyond the conventional Malassezia-centric view of SD pathogenesis is expected to enable the development of better therapeutic interventions for the management of recurrent SD