A multitechnique evaluation of topical corticosteroid treatment.

BACKGROUND/PURPOSE: Corticosteroids are widely prescribed for systemic or local treatment of inflammatory autoimmune disorders. Long-term therapy is associated with side effects and causes cutaneous atrophy of the epidermis and the dermis. The present study aims to evaluate with several noninvasive techniques, the skin modifications observed during corticosteroids treatment. The potential of skin mechanical measurement and ultrasound radio frequency (RF) signal analysis are proposed as new measures more closely related to the functional impairments. METHODS: Thirteen young healthy women volunteers had two applications per day on one arm of topical Clobetasol propionate 0.05% for 28 days, and they were followed for 28 days more. Skin modifications were studied by high-frequency ultrasound imaging, ultrasound RF signal analysis, optical coherence tomography and by the suction test. RESULTS: For all the techniques, a statistically significant change is observed with treatment. Large variations, around 30%, are observed for all techniques, but less for ultrasound imaging (10%). Dermis and epidermis thickness presented stable measurements on the nontreated zone. At the end of the study, measures returned to normal. The dynamic is mainly observed within the first 14 days of treatment and within the first 14 days after its cessation. CONCLUSION: Similar dynamics of skin modification during corticosteroid treatment was observed with very different techniques. Moreover, the potential of RF ultrasound analysis and mechanical skin measurement for characterizing skin structural and functional impairments has been evaluated.

Use of a 3-D imaging technique for non-invasive monitoring of the depth of experimentally induced wounds.

BACKGROUND/PURPOSE: Experimental studies of wound healing lack methods for standardized wounding and in situ depth assessment. Consequently, in this pilot study, an Erbium (Er):YAG laser has been used for wound induction with a non-invasive 3-D imaging technique as an alternative to histology. METHODS: Erbium:YAG ablation of human skin ex vivo was performed with total fluences of 10, 50 and 200 J/cm(2), removing the stratum corneum, epidermis/papillary dermis and deeper dermis, respectively. Wound depth was measured with the 3-D method and histologically. RESULTS: Wound depth was proportional to fluence for both techniques : 3-D, 17.7+/-1.7, 43.9+/-16 and 245.2+/-61 microm; histology, 14.6+/-1.7, 50.6+/-11.6 and 238+/-102 microm, respectively. CONCLUSIONS: The 3-D technique compares well with and is an improvement on histological measurement, providing true wound depth measurement, avoiding shape changes inherent with histology. Furthermore, the Er:YAG laser is a highly appropriate means of wound induction due to its rapidity and precision.