Alergia de contacto a benzocaína. Importancia de los resultados positivos concomitantes en las pruebas epicutáneas

Local anesthetics are widely used in clinical practice, and adverse effects are not uncommon. Delayed hypersensitivity reactions are among the most common effects, but immediate-type reactions may also occur. Patch testing should be considered in patients with hypersensitivity reactions. We present a case of allergic contact dermatitis to benzocaine that was detected incidentally by patch testing and highlight the importance of correctly interpreting patch test results when there are concomitant positive reactions.     

Perfil de los pacientes con dermatosis en las manos remitidos a la Unidad de Contacto de un hospital terciario e impacto de las pruebas epicutáneas en el diagnóstico

ObjectiveThis study aimed to define the epidemiological and clinical characteristics of patients referred to a contact dermatitis unit for hand dermatitis.Material and methodsWe retrospectively analyzed patients referred for hand dermatitis to the contact dermatitis unit of the Hospital Germans Trias i Pujol, Barcelona, Spain, between 2004 and 2007.ResultsA total of 96 patients were included. The most common diagnosis was irritant contact dermatitis, followed by allergic contact dermatitis, psoriasis, dyshydrosis, and atopic dermatitis. Standard patch tests were done for all patients and complementary batteries were ordered in 42 (44 %). Patch tests were positive in 59 % of the patients. Positive results were considered of present relevance in 59 %, of past relevance in 6 %, and of unknown relevance in the remaining positive tests. When proposed as the initial diagnosis, allergic contact dermatitis was confirmed in 67 % of the patients. The most frequent clinically relevant allergens were chrome, nickel, rosin, plant allergens, and p-phenylenediamine.ConclusionsHand dermatitis is a frequent presenting complaint in our contact dermatitis unit, with allergic contact dermatitis being the most common. Good correlation was found between presumed diagnosis of allergic contact dermatitis and the finding of clinically relevant allergens.     

Recomendaciones del Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC) de la AEDV en relación con la realización de pruebas epicutáneas durante la pandemia por SARS-CoV-2 (COVID-19)

As the COVID-19 pandemic gradually comes under control, the members of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) have drawn up a proposed list of the requirements, limitations, and conditioning factors affecting the resumption of work in contact dermatitis units. The assumption is that the severe acute respiratory syndrome coronavirus 2 is still circulating and that occasional or seasonal outbreaks will occur. They recommend that the first step should be to assess how many patch tests each clinic can handle and review the waiting list to prioritize cases according to disease severity and urgency. Digital technologies can, where possible, be used to send and receive the documentation necessary for the patch test (information, instructions, informed consent, etc.). If the necessary infrastructure is available, patients can be offered the option of a remote initial consultation. Likewise, in selected cases, the patch test results can be read in a virtual visit using photographs taken by the patient or a video visit can be scheduled to allow the physician to evaluate the site of application remotely. These measures will reduce the number of face-to-face visits required, but will not affect the time spent on each case, which must be scheduled in the normal manner. All of these recommendations are suggestions and should be adapted to the needs and possibilities of each health centre.