Intense focused ultrasound for facial tightening: histologic changes in 11 Patients.

INTRODUCTION: Intense focused ultrasound (IFUS) is a novel modality for treating skin laxity that produces thermal effects at various depths while sparing the overlying tissue. This study assessed histologic changes and the safety and efficacy of intense focused ultrasound (Doublo(TM), HIRONIC Co., Sungnam, Korea) for tightening of facial skin in Asian patients. METHODS: Eleven patients with facial laxity were treated with IFUS and evaluated before and after treatment. Mean age was 46 years (range, 35-64 years). Two available hand-pieces with different focal depths (3 mm and 4.5 mm) were used with three to five passes 1-2 mm apart. Outcome assessment included photographic evaluation by two blinded investigators, skin biopsies before and two months after treatment, and patient satisfaction. RESULTS: Subjective and objective analyses showed 63.6% and 72.7% improvement at the two-month evaluation, respectively. Histologic evaluation by hematoxylin and eosin (H&E) and Masson's trichrome staining showed increased collagen fibers in the lower dermis and between fat layers. DISCUSSION AND CONCLUSIONS: Intense focused ultrasound can be used as a non-invasive skin tightening technique in Asian patients. It induced collagen generation in the dermis and fat layers and was effective and safe in our study population.

Epidermotropic metastatic melanoma clinically resembling agminated spitz nevi.

Herein, we report a 36-year-old Asian male patient who presented with grouped multiple erythematous waxy papules and nodules on his right medial thigh. He had undergone amputation of the right second toe because of a stage IIa malignant melanoma, 3 years previously. At the time of surgery for the primary tumor, right inguinal lymph node dissection revealed no nodal involvement. Three years after the diagnosis of the primary tumor, crops of multiple erythematous papules and nodules developed. Initial histopathologic evaluation of the papules showed nests of small epithelioid cells similar to compound nevi. However, cytologic features, including high mitotic figures, lack of maturation, and some hyperchromatic nuclei suggested metastatic melanoma. In addition to the pathologic findings, the tumors were on the right thigh, which was the same side as the primary malignant melanoma. The patient underwent wide excision of the tumor and split-thickness skin grafting.

Evaluation of silica nanoparticle toxicity after topical exposure for 90 days.

Silica is a very common material that can be found in both crystalline and amorphous forms. Well-known toxicities of the lung can occur after exposure to the crystalline form of silica. However, the toxicities of the amorphous form of silica have not been thoroughly studied. The majority of in vivo studies of amorphous silica nanoparticles (NPs) were performed using an inhalation exposure method. Since silica NPs can be commonly administered through the skin, a study of dermal silica toxicity was necessary to determine any harmful effects from dermal exposures. The present study focused on the results of systemic toxicity after applying 20 nm colloidal silica NPs on rat skin for 90 days, in accordance with the Organization for Economic Cooperation and Development test guideline 411 with a good laboratory practice system. Unlike the inhalation route or gastrointestinal route, the contact of silica NPs through skin did not result in any toxicity or any change in internal organs up to a dose of 2,000 mg/kg in rats.