In vivo demonstration of immunologic cross-reactivity to octylisothiazolinone in patients primarily and strongly sensitized to methylisothiazolinone.

BACKGROUND: Notwithstanding that concomitant exposure to different isothiazolinone derivatives may result in concomitant sensitization, clinical and animal studies have suggested cross-reactivity between these derivatives, notably between methylisothiazolinone (MI) and octylisothiazolinone (OIT). OBJECTIVE: To investigate if patients sensitized to MI show cross-reactions to OIT and/or to benzisothiazolinone (BIT) by applying the concept of the re-test method. PATIENTS AND METHODS: From March to October 2019 consecutive patients were patch tested with MI 0.2% aqueous in duplicate at the two lower corners of both shoulder blades. Patients sensitized to MI, but not to OIT 0.1% petrolatum (pet.) nor to BIT 0.1% pet., were re-tested, 2 months later, with the latter two derivatives at the skin sites where the MI reactions had fully disappeared. RESULTS: Of 116 patients, 15 (13%) were sensitized to MI, eight of these not sensitized to BIT nor to OIT. Of these, seven patients, all (very) strongly sensitized to MI, were re-tested: five patients showed positive patch test reactions to OIT 0.1% pet.; one patient to OIT 0.1% pet. and BIT 0.1% pet.; and one other patient showed no reactions. CONCLUSION: This study suggests that patients primarily and strongly sensitized to MI may show immunologic cross-reactions to OIT, and to a far lesser extent to BIT.

[Analysis of a case series of adult patients with severe atopic dermatitis treated with dupilumab in Argentina]. / Análisis de una serie de casos de pacientes adultos con dermatitis atópica severa tratados con dupilumab en Argentina.

Introduction: Severe atopic dermatitis (AD) treatment is an unmet need, given the limited efficacy and safety of classical systemic treatments (CSTs). Dupilumab is a monoclonal antibody that blocks the signaling of the interleukins that mediate the inflammatory response involved in AD. Methods: the clinical response of a group of patients from Argentina with severe AD and insufficient response and/or toxicity to CSTs who were treated with dupilumab before commercial availability was analyzed. EASI, SCORAD, DLQI scales and analog visual scales of pruritus and sleep were evaluated, during a median follow-up of 189 days. In addition, the incidence of adverse events was analyzed. Results: 20 patients (13 male) were included; median age: 37.5 years; median AD evolution: 20 years; atopic comorbidity: 70%. 100% had received systemic corticosteroids (serious complications: 20%). Main reasons for discontinuation of CSTs were lack of efficacy and occurrence of adverse events. All scores were significantly and steadily reduced, with identifiable clinical response at the second month of treatment. At the end of the follow-up, only 3 patients required concomitant systemic immunosuppressive treatment. Dupilumab was well tolerated, with mild and controllable adverse events. Discussion: Dupilumab is the only biological agent with high efficacy demonstrated in clinical and observational studies. In this case series, its effectiveness was confirmed in difficult-to-treat patients with severe AD and inadequate response to CSTs. The safety profile was favorable and consistent.

Introducción: El tratamiento de la dermatitis atópica (DA) severa es una necesidad insatisfecha, dada la limitada eficacia y seguridad de los tratamientos sistémicos clásicos (TSC). Dupilumab es un anticuerpo monoclonal que bloquea la señalización de las interleuquinas mediadoras de la respuesta inflamatoria involucrada en la DA. Métodos: se analizó la respuesta clínica de un grupo de pacientes de Argentina con DA severa y respuesta insuficiente y/o toxicidad a los TSC que fueron tratados con dupilumab antes de su disponibilidad comercial. Se evaluaron las escalas EASI, SCORAD, DLQI y escalas visuales analógicas de prurito y sueño, durante una mediana de 189 días de seguimiento, así como la incidencia de eventos adversos. Resultados: Se incluyeron 20 pacientes (13 varones); mediana de edad: 37,5 años; mediana de evolución de la DA: 20 años; comorbilidad atópica: 70%. El 100% habían recibido corticoides sistémicos (complicaciones graves: 20%). Los principales motivos de suspensión de los TSC fueron falta de eficacia y aparición de eventos adversos. Los puntajes de todas las escalas se redujeron significativa y sostenidamente, con respuesta clínica evidente al segundo mes de tratamiento. Al final del seguimiento, solo 3 pacientes requerían tratamiento inmunosupresor sistémico concomitante. Dupilumab fue bien tolerado, con eventos adversos leves y controlables. Dsicusión: el dupilumab constituye el único agente biológico con elevada eficacia demostrada en estudios clínicos y observacionales. En esta casuística, se confirmó su efectividad en pacientes con DA severa de difícil tratamiento y respuesta inadecuada a los TSC. El perfil de seguridad resultó favorable y sostenido a mediano plazo.

Dermatitis por contacto a trementina / Contact dermatitis from turpentine

La trementina es una oleorresina extraída de varias especies de pinos y se utiliza principalmente como disolvente de pinturas, lacas y barnices. En la actualidad la dermatitis por contacto a esta sustancia es infrecuente por su reemplazo con otros productos menos sensibilizantes. A pesar de ello se observan algunos casos aislados de tipo laboral y extra-laboral. Se describe un caso de eccema por contacto ocupacional a la trementina, observando mejoría absoluta al evitar contacto con dicha sustancia y sus derivados...

Dermatitis por contacto a implantes metálicos / Contact dermatitis to metal implants

Las reacciones cutáneas a implantes metálicos, ortopédicos u otros, están bien documentadas en la literatura. Las reacciones de hipersensibilidad al metal de los dispositivos implantados siguen siendo un tema difícil y controvertido. Los criterios y los métodos de diagnóstico no están completamente delineados aún. Hay incertidumbresy desacuerdos sobre el papel causal de la sensibilidad al metal en el funcionamiento deficiente o ante implantes fallidos. La opinión, casi de consenso, es que las pruebas del parche deben ser consideradas para los pacientes con sospecha de hipersensibilidad al metal previo al implante y en las personas con sospecha de reacciones a los mismos. Presentamos dos pacientes con sensibilidad a implantes metálicos.

Skin reactions to metal or other orthopedic implants are well documented in the literature.Hypersensitivity reactions to metal implanted devices remains a difficult andcontroversial subject. The criteria and diagnostic methods are not yet fully delineated.In addition there are uncertainties and disagreements about the causal role ofmetal sensitivity in poor performance or implant failure. The current opinion, almostconsensual, is that patch testing should be considered for patients with suspectedhypersensitivity to metal prior to implantation and those with suspected reactions tothem. We are introducing two patientsthat developed contact dermatitis secondaryto metal implants.

Dermatitis alérgica por contacto a Lyral / Allergic contact dermatitis to Lyral®

La alergia de contacto a fragancias constituye un problema clínico importante. Su frecuencia se estima de 1 a 2% en la población general y alrededor del 8% en los pacientes con eccema de contacto. La sensibilización a fragancias se encuentra entre las causas más comunes de dermatitis alérgica por contacto, después del níquel y de los conservantes. Han surgido nuevas sustancias de detección con el finde aumentar la capacidad de diagnóstico de alergia a los perfumes. Desde el año 2005, una novedosa mezcla de fragancia compuesta por seis sustanciasse ha comercializado para su introducción en la batería estándar de alérgenos.El alérgeno más frecuente en esta mezcla es el Carboxaldehído hidroxilo isohexylcyclohexene (HICC) (Lyral ®).Se comunican cuatro pacientes con reacción positiva a Lyral® que han sido relevantes en relación al cuadro clínico.Este estudio ilustra que la alergia de contacto a fragancias es común en los pacientes que sufren de dermatitis de contacto...

Cutaneous and subcutaneous phaeohyphomycosis.

UNLABELLED: Case 1: A 17-year-old male rural worker from Bolivia living in La Plata (Argentina) for the past year had a lesion on the flexor side of his right forearm (6 x 4 cm). The lesion was formed by several confluent nodular areas, wine-red in color, some fistulized, with hemopurulent drainage. The area was hot and painless (Figure 1). On physical examination, no regional adenomegalies were reported. The following analyses were requested and results reported. Soft tissue ultrasound: material of solid consistency with layered liquid areas, located in the subcutaneous cellular tissue, with fistulous tract, connecting through superficial planes. Evidence of peripheral edema. Bacteriologic analysis (puncture aspiration): methicillin-sensitive Staphylococcus aureus. Mycologic analysis (puncture aspiration): negative; laboratory results: eosinophilia; and human immunodeficiency virus: nonreactive. Histopathologic examination: lesions of necrosis with granulomatous inflammatory reaction. Fungi techniques (periodic acid-Schiff, Grocott stains): negative. Bacilos acid-alcohol resistentes (acid-alcohol resistant bacillus) (BAAR) techniques (Kinyoun, Ziehl-Neelsen): negative. Foreign body examination tested with polarized light: negative. Mycologic and bacteriologic examinations were repeated, including a search for mycobacterium species using material obtained from the biopsy performed on the cutaneous lesion. Macromorphology: the colony was initially black and of creamy consistency, to later become velvety. Micromorphology: dark blastoconidia, then cylindrical phialides with elliptical conidia (Figure 2). IDENTIFICATION: Exophiala dermatitidis infection. On the basis of these characteristics, the diagnosis is phaeohyphomycosis due to Edermatitidis. The patient is treated with antimycotic therapy, with oral itraconazole (400 mg/d), plus indication of surgical procedure to remove the lesion. The patient's condition evolves favorably with no recidivant episodes after the sixth month post-treatment (Figure 3). During the first year, controls were scheduled every 2 months. Case 2: A 72-year-old diabetic man had a painful chronic varicose ulcer on the side of his left foot, with black friable exudate, 2x3 cm in diameter after 1 year. Every time the black material was removed, it would quickly grow back again. No response was obtained with different therapies applied to seal the lesion (Figure 4). Routine laboratory results included the following. Glucemy: 1.82 g/dL. Histopathology: filamentous septate fungal elements with positive Grocott stain (Figure 5 and Figure 6). Mycologic examination and culture: direct: fungal elements in dematiaceous group. Culture: positive for Curvularia lunata (Figure 7). The treatment selected was oral itraconazole (400 mg/d) for 12 months, with periodic laboratory controls, plus application of wet pads on the ulcer containing sodium borate and ketoconazole cream. At the fourth month, the ulcer had completely closed (Figure 8).