Knuckle pads are benign subcutaneous nodules that appear most frequently on the small joints of the hands. In children, they are often idiopathic, and no universally effective treatment has been reported. We present the case of an adolescent successfully treated with a combination of topical cantharidin -podophylotoxin -salicylic acid. | 545Pediatric Dermatology BRIEF REPORT with absent or peripheral vascularization on Doppler ultrasound.The surrounding soft tissue and tendons are normal. 5The differential diagnosis includes warts, rheumatoid nodules, gouty tophi, Bouchard's and Heberden's nodes, synovial cysts, tumors (giant cell tumor of the tendon sheaths, neurofibromas), and retained foreign bodies. In cases of diagnostic doubt, ultrasound and plain radiographs may be helpful. Magnetic resonance imaging has only been rarely described. 3,5 No effective treatment for KP has been reported in the literature, with behavior modification and psychiatric consultation showing the best results; watchful waiting is usually recommended. 4,5 This case presents an effective treatment alternative for patients with idiopathic KP, with both resolution of the lesions and acceptable cosmetic results. It is a non invasive approach with minimal complications (in this case, only mild pain that was managed with oral medication), which is particularly important considering that most patients are children.

El síndrome de la uña verde o cloroniquia corresponde a la infección por Pseudomonas aeruginosa de una lámina ungueal dañada en pacientes con algún factor de riesgo identificable, siendo los más frecuentes la inmunosupresión, el ambiente húmedo constante y la patología ungueal preexistente. Su diagnóstico es relativamente sencillo si se logra observar la tríada característica de coloración verdosa de la lámina ungueal, paroniquia proximal crónica y onicolisis distal; en casos de duda diagnóstica se puede enviar una muestra de la uña afectada para cultivos o estudio histopatológico. El pilar de su tratamiento corresponde al uso de antibióticos tópicos o sistémicos en conjunto con medidas generales que protejan de la humedad. Es muy importante enfatizar la prevención de esta patología en el personal de salud, especialmente en el contexto del lavado de manos frecuente y riguroso implementado durante la pandemia COVID-19, ya que existen reportes de transmisión nosocomial de P.aeruginosa por profesionales de la salud con infección ungueal.

Our case highlights the need to perform a skin biopsy in patients presenting with persistent vulvar itching, especially if they have not responded to conventional treatment for benign conditions.

No abstract

Reactive perforating collagenosis is a rare perforating dermatosis clinically characterized by intensely pruritic hyperpigmented papules, plaques, and nodules with a central keratotic plug. Histopathology reveals transepidermal elimination of collagen fibers. Its pathophysiology is still under investigation, but the acquired form has been linked to systemic conditions such as diabetes mellitus and chronic kidney disease. However, it has also been described as a paraneoplastic syndrome. The authors present the case of a 65-year-old diabetic patient in which a myeloproliferative neoplasm was suspected.