Eritema discromicum perstans (EDP) o dermatosis cenicienta: revisión a propósito de dos casos / Erythema discromicum perstans (EDP) or cystic dermatosis: review of two cases

El eritema discromicum perstans (EDP) o Dermatosis cenicienta es una entidad clínica poco común, de curso crónico e irreversible. Se presenta como máculas hiperpigmentadas color gris-ceniza, de tamaño y forma variable, distribuidas en cara, tronco, y extremidades. En Chile existen pocos casos reportados. La etiología es actualmente desconocida. Los hallazgos histopatológicos no son específicos de EDP, por lo que el diagnóstico es clínico e histopatológico. Aunque se han reportado múltiples opciones de tratamiento, ninguno ha demostrado ser efectivo de manera consistente. Presentamos dos casos de EDP y una revisión de los principales aspectos clínicos, epidemiológicos e histopatológicos de esta entidad.

Erythema dyschromicum perstans (EDP) or cinderella Dermatosis is an uncommon clinical entity, of chronic and irreversible course. Clinically it appears as hyper pigmented gray-ashy macules, of variable size and shape, distributed on face, trunk, and extremities. There are few cases reported on Chile. Etiology is currently unknown. The histopathological features are not characteristic of EDP, so the diagnosis is based upon clinical findings plus histopathology. Although there are several treatment options, none of them have been demonstrated to be consistently effective. We present two cases of EDP and a review of the clinical, epidemiological, and histopathological features of this entity.

Observation of a new electronic state of CO perturbing W ¹Π(v=1).

We observe photoabsorption of the W(1) ← X(0) band in five carbon monoxide isotopologues with a vacuum-ultraviolet Fourier-transform spectrometer and a synchrotron radiation source. We deduce transition energies, integrated cross sections, and natural linewidths of the observed rotational transitions and find a perturbation affecting these. Following a deperturbation analysis of all five isotopologues, the perturbing state is assigned to the v = 0 level of a previously unobserved (1)Π state predicted by ab initio calculations to occur with the correct symmetry and equilibrium internuclear distance. We label this new state E″ (1)Π. Both of the interacting levels W(1) and E″(0) are predissociated, leading to dramatic interference effects in their corresponding linewidths.