Atopic dermatitis in adults: a diagnostic challenge

Atopic dermatitis (AD) has a prevalence of 1%-3% in adults. Adult-onset AD has only been defined recently, and lack of familiarity with this condition and confusion regarding the appropriate terminology persist. AD may first appear in childhood or de novo in adults and is characterized by pronounced clinical heterogeneity. The disease often deviates from the classic pattern of flexural dermatitis, and there are forms of presentation that are specific to adults, such as head-and-neck dermatitis, chronic eczema of the hands, multiple areas of lichenification, or prurigo lesions. Although diagnosis is clinical, adult-onset AD frequently does not fit the traditional diagnostic criteria for the disease, which were developed for children. Thus, AD is often a diagnosis of exclusion, especially in de novo cases. Additional diagnostic tests, such as the patch test, prick test, skin biopsy, or blood test, are usually necessary to rule out other diseases or other types of eczema appearing concomitantly with AD. This article presents an update of the different forms of clinical presentation for AD in adults along with a proposed diagnostic approach, as new treatments will appear in the near future and many patients will not be able to benefit from them unless they are properly diagnosed (AU)

La dermatitis atópica (DA) en el adulto tiene una prevalencia del 1-3%. Es una entidad de reciente acuñamiento, que no todo el mundo conoce y sobre la que existe una gran confusión terminológica. Puede iniciarse en la infancia o presentarse de «novo» en el adulto. Presenta una gran heterogeneidad clínica y con frecuencia no sigue el patrón clásico de dermatitis flexural. Además, existen formas de presentación más propias de adulto como son la dermatitis de la cabeza y el cuello, eczema crónico de manos, áreas de liquenificación múltiple o lesiones de prurigo. Aunque su diagnóstico es clínico, muchas veces la DA del adulto no cumple los criterios diagnósticos «clásicos» de DA, pues están pensados para niños. Por eso, suele ser un diagnóstico de exclusión, sobre todo los casos de «novo». Suele precisar de la realización de pruebas diagnósticas para descartar otras enfermedades distintas u otro tipo de eczema sobreañadido a la DA. Las pruebas diagnósticas que pueden resultar útiles para ello son: pruebas epicutáneas, prick test, biopsia cutánea y una analítica sanguínea. Realizamos una actualización de las distintas formas de presentación clínica de la DA del adulto y establecemos unas pautas para llegar a su diagnóstico, pues en un futuro inmediato, con la aparición de nuevos tratamientos, muchos de estos pacientes no podrán beneficiarse de los mismos por no estar adecuadamente diagnosticados (AU)

Melanoma con fenómeno de Meyerson: características clínicas y dermatoscópicas / Melanoma With Meyerson's Phenomenon: Clinical and Dermoscopic Features

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Accumulation of invariant NKT cells into inflamed skin in a novel murine model of nickel allergy.

Nickel (Ni) can cause delayed-type hypersensitivity reactions, which are thought to be mediated by the accumulation of T cells into inflamed skin. Accumulated T cells at the developmental stages in metal allergy are poorly characterized because a suitable animal model has not been established. To investigate the accumulated T cells in allergic inflamed skin, we generated a novel murine model of Ni-induced allergy. The murine model of Ni allergy was induced by two sensitizations of Ni plus lipopolysaccharide solution into the groin followed by three challenges with Ni solution into the footpad. Here we show that a specific TCR repertoire bearing Vα14Jα18, called natural killer (NK) T cells, was expanded monoclonally in BALB/c or C57BL/6 mice. Accumulation of NKT cells was characterized as CD4(+) or CD4(-)CD8(-) T cells. These results suggested that NKT cells are major pathogenic T cells at the elicitation phase of Ni allergy.

Eccema de contacto alérgico: fisiopatología / No disponible

La penetración de un antígeno vía epidermis, va seguida de su captación a través de las células de Langerhans y células dendríticasepidérmicas que se estimulan y viajan a los ganglios linfáticos regionales donde presentan a los Linfocitos T el alérgeno para que estas células se multipliquen y sean las células que posteriormente defiendan al organismos frente a nuevos contactos con el alérgeno. Esta secuencia bien conocida va acompañada por la formación y liberación de diversos clones celulares y citoquinas que aún hoy no son del todo conocidas (AU)

The penetration of an antigen through skin followed by its uptake by Langerhans cells; determine that the dendritic cells are stimulated to travel to regional lymph nodes where they present the allergen to T lymphocytes. These cells multiply and are subsequently cells that defends the body against further contact with the allergen. This well-known sequence is accompanied by the formation and release of different cell clones and cytokines that are still not well understood (AU)

The role of allergic sensitisation in childhood eczema: an epidemiologist’s perspective

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Measurement of serum immunoglobulin E (IgE) specific for house dust mite antigens in normal cats and cats with allergic skin disease.

The purpose of this study was to determine whether cats with allergic skin disease have significant concentrations of serum Immunoglobulin E (IgE) specific for antigens derived from the house dust mites (HDM) Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus (DP). Enzyme-linked immunosorbent assays (ELISA) were developed for this purpose. Binding of serum allergen-specific IgE was detected via the use of biotinylated Fc-epsilon receptor alpha chain protein (FcvarepsilonRIalpha). Following optimisation of the assay, serum samples from 59 cats with allergic skin disease and 54 clinically normal cats were screened. Results were expressed as ELISA units per ml (EU/ml) compared to a standard curve. Serological findings were correlated with the clinical presentation of affected cats. Cats with symptoms of feline allergic skin disease were grouped as follows: self-induced alopecia without lesions (group 1), papulocrusting dermatitis (group 2), eosinophilic granuloma complex (group 3), papular/ulcerative dermatitis of head and neck/facial dermatitis (group 4), and a combination of symptoms (group 5). Control normal cats comprised the final group (group 6). The Kruskal-Wallis test was used for statistical analysis. There was no significant difference between groups for DF- and DP-specific IgE concentrations with a p-value of 0.875 and 0.705, respectively. Although the FcvarepsilonRIalpha-based ELISA was able to detect house dust mite-specific feline IgE, the presence of this allergen-specific IgE correlates poorly with the presence of clinical manifestations of allergic skin disease. The results of this study question the clinical relevance of house dust mite-specific IgE in feline allergic skin disease.

Exposure to selected fragrance materials. A case study of fragrance-mix-positive eczema patients.

The aim of the present study was to assess exposure to constituents of the fragrance mix from cosmetic products used by fragrance-mix-positive eczema patients. 23 products, which had either given a positive patch and/or use test in a total of 11 fragrance-mix-positive patients, were analyzed. In all cases, the use of these cosmetics completely or partly explained present or past episodes of eczema. Between 1 to 6 constituents of the fragrance mix were found in 22 out of 23 products. The cosmetics of all the patients sensitive to hydroxycitronellal, eugenol, cinnamic alcohol and alpha-amylcinnamic aldehyde were found to contain the respective substances. Exposure concentrations were seen to cover a large range. The content of hydroxycitronellal was, on average, 5 x higher in cosmetics from hydroxycitronellal-sensitive patients, compared to cosmetics from hydroxycitronellal-negative patients. It is concluded that exposure to constituents of the fragrance mix is common in fragrance-allergic patients with cosmetic eczema, and that the fragrance mix is a good reflection of actual exposure.

Common allergic skin conditions.

Skin conditions regarded as having an 'allergic' origin are extremely common. Immunologically specific hypersensitivities to food and aeroallergens and idiosyncratic reactions to food chemicals play a role in some of the individuals suffering from these conditions, but in others intrinsic or unknown factors dominate. Rashes are frequently seen in relation to food intolerance and adverse drug reactions that share common mechanisms.