SARS-CoV-2 and Other Respiratory Viruses: What Does Oxidative Stress Have to Do with It?

The phenomenon of oxidative stress, characterized as an imbalance in the production of reactive oxygen species and antioxidant responses, is a well-known inflammatory mechanism and constitutes an important cellular process. The relationship of viral infections, reactive species production, oxidative stress, and the antiviral response is relevant. Therefore, the aim of this review is to report studies showing how reactive oxygen species may positively or negatively affect the pathophysiology of viral infection.

Proinflammatory and regulatory mechanisms in allergic contact dermatitis caused by methylchloroisothiazolinone and methylisothiazolinone.

Background: Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are the cause of an increasing number of contact allergies. Understanding the mechanisms by which MCI/MI induces proinflammatory and regulatory factors production is necessary to understand the outcome of allergic contact dermatitis (ACD).

Objectives: To evaluate the dysfunction of proinflammatory cytokines and regulatory factors in the positive MCI/MI patch test at the transcriptional and protein expression levels.

Experience in management of porphyria cutanea tarda in a tertiary referral Brazilian hospital from 2002 to 2017.

Background: Porphyria cutanea tarda (PCT) is the most common porphyria worldwide. The known acquired precipitating factors that induce PCT include alcoholism, hepatitis C virus infection, human immunodeficiency virus infection, and estrogen intake. Hereditary hemochromatosis is considered an inherited risk factor.

Evaluation of the profile of inflammatory cytokines, through immunohistochemistry, in the skin of patients with allergic contact dermatitis to nickel in the acute and chronic phases.

Background: Allergic contact dermatitis to ion nickel (Ni+2) is an inflammatory dermatosis, common in industrialized countries. It involves the activation of nickel-specific T-cells, followed by proliferation and induction of a mixed profile of both proinflammatory and regulatory cytokines, suggesting that several T-cell subtypes (helper - Th and cytotoxic - Tc) are involved. A broader understanding of the cytokine profile may lead to new therapeutic approaches.

Innate immunity and effector and regulatory mechanisms involved in allergic contact dermatitis.

Skin's innate immunity is the initial activator of immune response mechanisms, influencing the development of adaptive immunity. Some contact allergens are detected by Toll-like receptors (TLRs) and inflammasome NLR3. Keratinocytes participate in innate immunity and, in addition to functioning as an anatomical barrier, secrete cytokines, such as TNF, IL-1β, and IL-18, contributing to the development of Allergic Contact Dermatitis.

Brazilian consensus on photoprotection.

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long.

Chronic urticaria in adults: state-of-the-art in the new millennium.

Chronic urticaria has been explored in several investigative aspects in the new millennium, either as to its pathogenesis, its stand as an autoimmune or auto-reactive disease, the correlation with HLA-linked genetic factors, especially with class II or its interrelation with the coagulation and fibrinolysis systems. New second-generation antihistamines, which act as good symptomatic drugs, emerged and were commercialized over the last decade. Old and new drugs that may interfere with the pathophysiology of the disease, such as cyclosporine and omalizumab have been developed and used as treatments.

Cytokine detection for the diagnosis of chromium allergy.

Background: Patch testing remains the gold standard method for the identification of the etiologic agent of allergic contact dermatitis. However, it is a subjective, time-consuming exam whose technique demands special care and which presents some contraindications, which hamper its use. In a recent study, we showed that the proliferation assay can suitably replace patch testing for the diagnosis of chromium allergy, which had been previously demonstrated only for nickel allergy.

Tungiasis under dermoscopy: in vivo and ex vivo examination of the cutaneous infestation due to Tunga penetrans.

The female flea Tunga penetrans is responsible for a cutaneous parasitosis known as Tungiasis. We report the clinical case of a 12 year-old Caucasian boy who sought treatment in a dermatological private office due to a painful lesion in the plantar area and whose dermoscopic examination, without skin contact, allowed the visualization of parasite's movement inside the skin. The diagnosis of tungiasis is clinical, but it can be aided by in vivo and ex vivo dermoscopic examination of the lesion.

Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients.

Background: Porphyria cutanea tarda is the most common form of porphyria, characterized by the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several reports associated HFE gene mutations of hereditary hemochromatosis with porphyria cutanea tarda worldwide, although up to date only one study has been conducted in Brazil.

Objectives: Investigation of porphyria cutanea tarda association with C282Y and H63D mutations in the HFE gene.

Evaluation of D-dimer serum levels among patients with chronic urticaria, psoriasis and urticarial vasculitis.

Background: It has been demonstrated that neutrophils, eosinophils and monocytes, under appropriated stimulus, may express tissue factor and therefore, activate the extrinsic pathway of coagulation. We performed a transversal and case-control study of patients with chronic urticaria and patients with psoriasis, in our outpatient clinic to evaluate the production of D-dimer.

Objective: To evaluate D-dimer serum levels in patients with chronic urticaria and its possible correlation with disease activity.

Quality of life of patients with paucibacillary leprosy.

Background: Leprosy, an infectious disease caused by Mycobacterium leprae, can affect the skin and the peripheral nervous system and, depending on the level of involvement, it can lead to severe deformities. Leprosy is classified into two major groups: paucibacillary (up to five lesions) and multibacillary (more than five lesions). The deformities that appear during the progress of the disease can affect the quality of life.

Sun protection factor: meaning and controversies.

The Sun Protection Factor (SPF) is the most important data to quantify the effectiveness of a sunscreen, being universally accepted. The method is based on determining the minimum erythematous dose (MED), defined as the smallest amount of energy required for triggering the erythema, in areas of protected and unprotected skin. The SPF value is then calculated as the ratio between the MED of protected and unprotected skin.

Immunopathology of allergic contact dermatitis.

Allergic contact dermatitis is the consequence of an immune reaction mediated by T cells against low molecular weight chemicals known as haptens. It is a common condition that occurs in all races and age groups and affects the quality of life of those who present it. The immunological mechanism of this disease has been reviewed in recent decades with significant advance in its understanding.

Dermatosis due to plants (phytodermatosis).

Dermatosis caused by plants is relatively common and may occur by various pathogenic mechanisms. Dermatitis due to physical trauma, pharmacological action, irritation, sensitization, mediated by IgE and induced by light are described. Pseudophytodermatosis caused by plant-delivered elements is also described in the introduction to this work.

The influence of the amount of sunscreen applied and its sun protection factor (SPF): evaluation of two sunscreens including the same ingredients at different concentrations.

Background: To estimate labeled sun protection factor (SPF) for sunscreen, the amount of product applied on volunteers, according to food and drug administration (FDA) and International protocols, is 2 mg/cm(2). However, different studies have shown that consumers actually apply much less product when exposed to the sun. Previous studies have reported contradictory findings in an attempt to correlate the amount applied in relation to SPF.

Discoid lupus erythematosus in children--a retrospective study of 34 patients.

Discoid lupus erythematosus is much less frequent and studied in children. We undertook a retrospective study of 34 children less than 16 years of age with this disease, seen over a period of 9 years. A female predominance of 2:1 was found.

Direct immunofluorescence on uninvolved, lesional and perilesional skin in patients with endemic pemphigus foliaceus (fogo selvagem).

Background: Research on direct immunofluorescence in pemphigus foliaceus ("fogo selvagem") has been focused mainly on the study of perilesional and lesional skin, while little attention has been given to uninvolved skin. We analyzed the frequency of IgA, IgM, IgG and its subclasses (IgG1, IgG2, IgG3 and IgG4) and C3 complement fraction deposition in intercellular spaces (ICS) and basal membrane zone (BMZ) in uninvolved, lesional and perilesional skin from 47 fogo selvagem patients.

Material/methods: For each patient biopsies were collected from lesional, perilesional and uninvolved skin, and then analyzed by direct immunofluorescence.