Evaluation of Device-Based Cutaneous Channels Using Optical Coherence Tomography: Impact for Topical Drug Delivery

BACKGROUND

Topical medications play a large role in the management of cutaneous diseases, but penetration is limited. Device-assisted drug delivery using mechanical destruction, lasers, and other energy-based modalities can increase penetration and absorption through creation of transcutaneous channels.

OBJECTIVE

To examine real-time, in vivo cutaneous changes in response to various devices used to improve topical drug delivery through optical coherence tomography (OCT) imaging.

METHODS AND MATERIALS

Treatment was performed with 8 medical devices, including mechanical destruction, lasers, and other energy-based modalities. Optical coherence tomography was used for real-time, noninvasive, in vivo imaging.

RESULTS

Using OCT, microneedling and radiofrequency microneedling demonstrated no cutaneous channels. Both low-energy, low-density, fractional nonablative lasers produced transient channels, which closed within hours. The fractional nonablative 1,927-nm thulium fiber and 1,550-nm erbium fiber lasers created channels with epidermal debris within, which were still closing at 24 hours. The fractional thermomechanical ablative device and the fractional ablative CO2 laser produced channels that were still open at 24 hours. CO2 laser channels had thick rims of coagulated tissue and remained open for longer.

CONCLUSION

Demonstrable differences among the devices were seen, and only some can produce observable channels, the characteristics of which vary with each technology.

Topical Timolol Combined Intralesional Injection of Diprospan in the Treatment of Elevated Localized Mixed Infantile Hemangiomas and a Discussion for Proper Timing for Injection

BACKGROUND

Although infantile hemangiomas (IHs) are usually self-limiting, residual elevated appearance may remain. Topical beta-blockers are effective in superficial IHs management, while intralesionally injected diprospan is effective at treating deep, localized IHs. A single application of topical timolol or injected diprospan has obvious limitations. Therefore, for elevated, localized mixed IHs, we applied topical timolol combined with intralesionally injected diprospan, using their respective advantages to maximize benefits.

PURPOSE

To evaluate the clinical efficacy and safety of topical timolol combined with intralesionally injected diprospan for the treatment of elevated, localized mixed IHs and identify the optimal injection time.

METHODS

Infants with elevated, localized mixed IHs in the proliferative phase were treated with injected diprospan combined with topical timolol between March 2018 and March 2020. The injection was administered only when the tumor surface was higher than that of the surrounding tissue. The patients were asked to return every 4 weeks for a treatment response evaluation, and complications were recorded.

RESULTS

Thirty-six patients with elevated, localized mixed IHs (thickness >3 mm on Doppler ultrasound) were recruited. The mean age at treatment initiation was 3.58 ± 1.50 months (range: 1.00-6.00 months). The follow-up period ranged from 9 to 24 months. Considering the size of the IH at the end of treatment, regression was observed in 31 (86.1%) cases, stabilization was observed in 5 (13.9%) cases, and no treatment failure was observed. All the IHs improved in color and height after treatment.

CONCLUSION

Topical timolol combined with intralesionally injected diprospan is an effective and safe treatment for elevated, localized mixed IH. The injection is needed only when we forecast the elevated tissue may remain after regression.