Novedades en el diagnóstico de las toxicodermias

Drug eruptions affecting the skin or mucosas (toxicoderma) are the most common adverse effects of drugs and represent one of the more common diagnostic challenges for the dermatologist. A better understanding of the pathogenic mechanisms of drug reactions, pharmacogenetics, and pharmacoepidemiology will help us to resolve the main dilemmas and to anticipate and even prevent such reactions. Many drug eruptions are due to T cell–mediated hypersensitivity reactions that can involve activation of different proinflammatory mechanisms, which would explain the varied manifestations. Some aspects defy the classical understanding of antigen processing and presentation. New immunological hypotheses, such as the «p-i concept», have been introduced to complement the hapten theory and, at least in part, help to explain why drug reactions tend to affect the skin and why certain viral infections increase the risk of drug eruptions. In this paper we analyze these pathogenic concepts and the role of HLA genes in the susceptibility to certain severe adverse drug reactions, and also examine other advances in the diagnosis of drug eruptions. We briefly discuss a number of recently described reactions to new drugs.     

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.     

[Artículo traducido] Cauterización de la matriz con nitrato de plata para el tratamiento de las uñas encarnadas en los dedos de los pies en niños: estudio piloto

BackgroundAlthough partial onychectomy with chemical matricectomy has been described asthe treatment of choice, there is sparse evidence in the literature regarding the use of silvernitrate for matricectomy. Our aim is to describe the effectiveness of silver nitrate for matrixcauterization after partial onychectomy.MethodsA prospective observational study was performed on patients with ingrown toenailsstage 2–3 who underwent partial onychectomy with silver nitrate chemical matricectomy during 2018–2019 in our institution. All patients were evaluated in the outpatient clinic on the 7th and 30th post-operative day and a telephone evaluation was performed every 6 months afterthe surgical procedure to date.ResultsOne hundred and twenty-three patients, who underwent 231 partial onychectomies with silver nitrate chemical matricectomy were included, with a median follow-up of 21 months (interquartile range, 12–29). The procedure had an effectiveness of 95.3%, with only 11 recur-rences (4.7%) reported so far on follow-up. Postoperative infections were observed in 4 patients (1.7%). Adverse effects, such as pain and postoperative drainage, were irrelevant in mostpatients.ConclusionsSilver nitrate matricectomy after partial onychectomy is an effective and safealternative for the treatment of ingrown toenail in children, with scarce postoperative morbidityand low recurrence rate.     

Seguridad en procedimientos dermatológicos: complicaciones oftalmológicas

Ophthalmological complications are uncommon in dermatologic surgery. Nonetheless, all surgeons should know the basics of recognizing, preventing, and treating the 4 complications addressed in this article from the series ‘Safety in Dermatologic Procedures’. The first complication that surgeons should be familiar with is eye damage due to chemical irritants. This is a common complication in operating rooms given the presence of irritant substances and the performance of procedures in the eyebrow and eyelid region. The second complication is laser-induced eye damage. In this case, eye protection with safety glasses or eye caps is crucial. The third complication is accidental eyeball perforation, which can occur during certain surgical procedures. The fourth and final complication is retinal artery vasospasm or embolism due to drugs or filler materials. This complication is rare but important to recognize, as early treatment can prevent permanent blindness.     

Complicaciones y secuelas dermatológicas de quemaduras en lactantes y preescolares chilenos

IntroductionBurns are injuries that compromise skin or other organic tissues, caused by different mechanisms. The paediatric population is especially susceptible to accidental burns and their subsequent sequelae. This study aimed to characterise the burns suffered by infants and pre-school children, with emphasis on the development and evolution of complications and cutaneous sequelae.MethodologyA retrospective cohort study based on clinical records of children under 6 years old who suffered skin burns, in whom 1 to 2 years of follow-up was completed.ResultsThe study included 59.2% males, and the mean age was 25.7 ± 6.2 months. Most (64.8%) burns occur in autumn and winter. The most frequent sources of burns were: hot liquids (63.4%) and hot objects (31%). The large majority (88.7%) of the burns were of partial thickness, and covered a mean of 2.4 ± 1.1% of body surface. The hands and upper extremities were the most affected locations, and 42.3% of patients required surgery in the acute period. Of the total burned body locations, 73.7% had one or more complications or cutaneous sequelae. The lower extremities were the most affected by complications. The frequency of complications was: keloids and hypertrophic scars (22%), hyperpigmentation (18%), hypopigmentation (14%), pruritus (14%), wounds and excoriations (12%), and infections (1%).ConclusionsThis series constitutes one of the first studies on the paediatric population affected by burns focused from a perspective on complications. Knowledge of this information is essential for the development of prevention and management strategies.     

Estudio retrospectivo de las características clínicas,histológicas e inmunológicas en una serie de 9 pacientes con epidermólisis ampollosa adquirida

IntroductionEpidermolysis bullosa acquisita (EBA) is an autoimmune subepidermal blistering disease caused by autoantibodies to type VII collagen. The clinical presentation is variable, with skin and mucosal lesions that can cause significant dysfunction. Different treatment options exist, but the results are often unsatisfactory.ObjectiveTo review all the cases of epidermolysis bullosa acquisita (EBA) diagnosed at our hospital over a 26-year period.Materials and methodsWe performed a retrospective review of the clinical, histologic, and immunologic features of EBA in 9 patients.ResultsMean age at presentation was 37 years and 66.67% of the patients were women. EBA occurred in association with malignant tumors, inflammatory bowel disease, and autoimmune disorders. The most common variant was inflammatory EBA (6 of the 9 cases). In all 9 patients, histology revealed a subepidermal blister and direct immunofluorescence showed linear deposits of immunoglobulin G and C3 in the basement membrane zone. Indirect immunofluorescence performed on salt-split skin substrate was positive in 6 patients and showed a dermal pattern in all cases. Five patients were tested for autoantibodies to type VII collagen using enzyme-linked immunosorbent assay, with positive results in 2 cases. Immunoblotting using recombinant noncollagenous domains (NC1) of type VII collagen was positive in all 6 cases in which it was performed. Response to treatment was variable.ConclusionsEBA is a rare disease with a variable clinical presentation that can be confused with that of other subepidermal blistering diseases. Correct diagnosis requires a high level of clinical suspicion and the use of all available diagnostic tests. Thorough evaluation of cutaneous and mucosal involvement and prompt initiation of appropriate treatment will ensure the detection and prevention of dysfunction and treatment-related complications.     

[Artículo traducido] Bloques celulares obtenidos de la punción-aspiración con aguja fina ecoguiada: rendimiento diagnóstico en una serie de 51 lesiones dermatológicas

The generation of cell blocks (CBs) obtained from ultrasound-guided fine needle aspiration biopsies (USFNAB) is a well-established technique in breast and thyroid pathology, but is rarely used in dermatology. We reviewed CBs obtained from USFNAB of skin lesions, which were categorized as malignant skin tumors, benign skin tumors, inflammatory skin tumors or deposit skin diseases. The diagnostic yield of each category was compared to histopathology. The USFNAB of 51 skin lesions was processed into CBs. There was overall agreement between histopathology and CBs in 84.31% of cases. Diagnostic group concordance for benign, malignant as well as inflammatory and deposit skin lesions were 69.2%, 93.7% and 86.3% respectively. Cell block generation from USFNAB aspirates of skin lesions should be considered as part of the dermatologic diagnostic armamentarium. Further experience is needed to better understand for which types of dermatologic lesions it would be clearly indicated.     

Tratamiento quirúrgico de lesiones dermatológicas en pacientes pediátricos

IntroductionThere are currently several anesthetic options, such as the use of topical anesthetics and conscious sedation, which have become an effective alternative for carrying out surgical procedures in small children or in those who present with too much anxiety during surgery. The objective of this study is to carry out a retrospective study of children who have undergone surgery for dermatological lesions in our department in a two-and-a-half-year period.Patients and methodWe reviewed the clinical and anesthetic histories of children who underwent surgery performed by the Dermatology Department of Hospital General de Alicante in the pediatric Outpatient Surgical Unit (OSU) and in the dermatology operating room, between 2000 and 2002. The following variables were obtained for each patient: age, gender, diagnosis, type of anesthesia and postoperative complications.ResultsA total of 96 children had surgery with local anesthesia, and 83 children had surgery in the pediatric OSU. All of the patients who had surgery with local anesthesia were over the age of 6, and in the OSU, 77.1 % were under 10. The most frequent diagnosis (50 %) in both groups of patients was a melanocytic nevus. 95.2 % of the OSU patients received a sedation technique, and 4.8 % general anesthesia. The only postoperative complication was pain, which occurred in < 10%, and which was controlled with metamizole.ConclusionThe anesthesia techniques used in the OSU were generally well accepted by the children, due to the fact that they provided greater comfort for the patients, who did not suffer during surgery, and reduced postoperative pain. Pediatric sedation techniques are an alternative in dermatological surgery, especially for surgery in small children or for large lesions.