Angioedema is defined as edema of the skin or mucosa, including the respiratory and the gastrointestinal mucosa, which is self-limiting, and in most cases is completely resolved in less than 72 hours. It occurs due to increased permeability of the mucosal and submucosal capillaries and postcapillary venules, with resulting plasma extravasation. There are different types of angioedema: histaminergic (which may be mediated by immunoglobulin E), hereditary, from acquired C1 inhibitor deficiency, from angiotensin converting enzyme inhibitor, bradykinin-mediated, and nonhistaminergic idiopathic angioedema. Treatment depends on the cause of angioedema, age, and the frequency and severity of manifestations. The main measures are avoiding external triggers or causes, giving antihistamines, steroids, or adrenaline for histaminergic angioedema; replacing the deficient protein or blocking the action of bradykinin in C1 inhibitor deficiency and angioedema from angiotensin converting enzyme inhibitor.

Erythema dyschromicum perstans (EDP) is a pigmentary disease of unknown etiology in which damage to basal cells is thought to be mediated by adhesion molecules. The aim of this study was to characterize the histopathology and immunopathology of EDP. Forty-three patients from Medellín, Colombia, with the diagnosis of EDP were evaluated. Skin biopsy specimens were obtained for histopathology and immunohistochemistry, using monoclonal antibodies directed against the following markers: CD4, CD8, CD56, CD1a, CD68, CLA, HLA-DR, ICAM-1 and LFA-1alpha. A dermal lymphocytic infiltrate was observed in all cases, with a perivascular location in 86%. Other histologic features included melanophages in all specimens, vacuolization of the basement membrane zone (BMZ) 58% and exocytosis of lymphocytes (53.5%). The mean number of total leukocytes was 1510 cells mm-2 of tissue. There was a predominance of CD8+ T lymphocytes in the dermis and HLA-DR+, ICAM-1+ keratinocytes in the epidermis. Exocytosis of cutaneous lymphocyte antigen (CLA)+cells was observed in areas of BMZ damage, suggesting that response to antigenic stimulation may play a role in the development of EDP.

Background Sporotrichosis is a subcutaneous mycosis caused by dimorphic fungi of the genus Sporothrix. The route of entry of the causative agent is direct inoculation by skin trauma, generally with decaying wood and other vegetation. However, cat-transmitted sporotrichosis has become more relevant in recent decades especially in South America.Until now, there are no case reports of cat-transmitted sporotrichosis in Colombia. Case reportWe present three cases of cutaneous sporotrichosis after the scratches of an ill cat, in the feline's owners and its veterinarian, confirmed by culture and PCR, where S. schenckii sensu stricto was isolated and typified.Conclusions Cat-transmitted sporotrichosis is becoming more relevant in recent decades due to its potential to generate epidemics and become a public health problem. In addition, since the associated species are more virulent, the disease has more aggressive behavior. In Colombia, this is the first case series of cat-transmitted cutaneous sporotrichosis.

Las manifestaciones cutáneas relacionadas a la infección por el coronavirus SARS-CoV-2, causante de COVID-19, se han descrito entre el 0,2% y 20,4% de las personas que cursan con esta enfermedad. Las más frecuentemente descritas son: lesiones maculopapulares (47%), lesiones acrales eritematosas con vesículas o pústulas (pseudoperniosis) (19%), urticariales (19%), lesiones vesiculosas (9%) y livedo/necrosis (6%). En particular, la pitiriasis rosada es una dermatosis autolimitada de etiología desconocida, sin embargo, se ha visto asociada a la infección por SARS-CoV-2, con algunos reportes de casos en la literatura. El mecanismo fisiopatológico de las lesiones cutáneas en COVID-19 no es claro, y se han planteado algunas teorías, entre las cuales está el papel que juega la enzima convertidora de angiotensina 2 (ACE2) utilizada por el virus para infectar las células, los infiltrados linfocíticos, los depósitos de factores del complemento en la piel, y la reactivación de virus latentes como los herpes virus humanos. Se presenta el caso de una paciente con pitiriasis rosada asociada a COVID-19 y se describen los casos reportados hasta la fecha.