Updated understanding of Staphylococcus aureus in atopic dermatitis: From virulence factors to commensals and clonal complexes.

Atopic dermatitis (AD) is a common inflammatory dermatosis that has multiple contributing factors including genetic, immunologic and environmental. Staphylococcus aureus (SA) has long been associated with exacerbation of AD. SA produces many virulence factors that interact with the human skin and immune system. These superantigens and toxins have been shown to contribute to adhesion, inflammation and skin barrier destruction. Recent advances in genome sequencing techniques have led to a broadened understanding of the multiple ways SA interacts with the cutaneous environment in AD hosts. For example, temporal shifts in the microbiome, specifically in clonal complexes of SA, have been identified during AD flares and remission. Herein, we review mechanisms of interaction between the cutaneous microbiome and SA and highlight known differences in SA clonal complexes that contribute to AD pathogenesis. Detailed knowledge of the genetic strains of SA and cutaneous dysbiosis is becoming increasingly relevant in paving the way for microbiome-modulating and precision therapies for AD.

Bullous acral eruption related to secukinumab.

Skin reactions related to secukinumab are uncommon. Although the initial phase 3 studies of this medication reported infection and urticaria as adverse cutaneous events, other cases of unique adverse events have since been reported. We are presenting a patient who developed an exuberant hand and foot reaction after starting secukinumab.

Chronic social stress Ameliorates psoriasiform dermatitis through upregulation of the Hypothalamic-Pituitary-Adrenal axis.

Acute stress is a physiological response of an organism to adverse conditions, contributing to survival; however, persistence through time may lead to disease. Indeed, exacerbation of inflammatory conditions such as psoriasis has been reported to follow stressors in susceptible patients. Because chronic stress cannot ethically be elicited in patients under controlled laboratory conditions, we studied genetically modified mice that naturally develop psoriasiform dermatitis, and subjected them to an ethological chronic social contact stress paradigm. Although we found elevated pro-inflammatory neuropeptide production of substance P (SP), calcitonin-gene-related peptide (CGRP) and nerve-growth factor (NGF) mRNA in the dorsal root ganglia (DRG) as well as pro-inflammatory cytokines in response to the social stressor, stress paradoxically prevented the development of the skin lesions. This effect of stress could be reversed by the treatment with glucocorticoid (GC) receptor blockers, suggesting that it was mediated through the upregulation of corticosterone secretion. Extrapolating to humans, the worsening of disease in susceptible patients with psoriasis could be attributed to a defect in the Hypothalamic-Pituitary-Adrenal (HPA) axis with an impaired production of GC during situations of adversity, thus rendering them unable to counteract the pro-inflammatory effects of chronic stressors.

Natural ingredients for darker skin types: growing options for hyperpigmentation.

Dyschromia is one of the most common dermatological concerns in patients with darker skin.1 Disorders of hyperpigmentation, including postinflammatory hyperpigmentation, melasma, solar lentigines, and miscellaneous causes of facial hyperpigmentation, are the most frequently treated dyschromias and can have a considerable psychosocial impact. Given the high prevalence of hyperpigmentation and the considerable demand for an even complexion, newer treatment options for hyperpigmentation are of growing interest among consumers, manufacturers, and dermatologists. Blinded, controlled studies demonstrating skin lightening effects in soy, niacinamide, n-acetylglucosamine, licorice extract, arbutin, vitamin c, kojic acid, emblica extract, lignin peroxidase, and glutathione have led to the development of a growing list of non-prescription skin care products that can be incorporated (mostly as adjuncts) in the management of hyperpigmentation.