Sequential treatment of actinic keratosis with cryotherapy and ingenol mebutate: reflectance confocal microscopy monitoring of efficacy and local skin reaction

Abstract

Both sequences of treatment are effective, but IM treatment before cryotherapy is recommended because of the lower LSR. This probably decreases patient discomfort and improves compliance.

In Vivo Reflectance Confocal Microscopy as a Response Monitoring Tool for Actinic Keratoses Undergoing Cryotherapy and Photodynamic Therapy

“…Our identification of atypical honeycomb patterns as a reliable RCM parameter for AK is consistent with many reports highlighting the utility of keratinocyte disarray/atypical honeycomb patterns in AK response monitoring [ 11 , 12 , 13 , 23 , 24 , 25 , 26 , 27 , 28 ]. Hyperkeratosis [ 8 , 13 , 15 , 17 , 23 , 25 , 29 ] and stratum corneum disruption [ 8 , 11 , 12 ] have also been identified as significant RCM parameters, although many studies have not included these criteria in the RCM analysis of AK treatment responses.…”

“…Our identification of atypical honeycomb patterns as a reliable RCM parameter for AK is consistent with many reports highlighting the utility of keratinocyte disarray/atypical honeycomb patterns in AK response monitoring [ 11 , 12 , 13 , 23 , 24 , 25 , 26 , 27 , 28 ]. Hyperkeratosis [ 8 , 13 , 15 , 17 , 23 , 25 , 29 ] and stratum corneum disruption [ 8 , 11 , 12 ] have also been identified as significant RCM parameters, although many studies have not included these criteria in the RCM analysis of AK treatment responses. Interestingly, following its use in early clinical trials [ 6 , 16 ], future studies largely omitted disarranged epidermal pattern/epidermal disarray as an RCM criterion for AK, likely due to difficulty in standardization related to its varying definitions (ranging from cytological atypia, disordered keratinocyte maturation and/or architectural patterns) and challenges in its differentiation from similar epidermal parameters.…”

“…For instance, epidermal hyperplasia, epidermal atrophy, acanthosis, digitated, papillated, reticulated, basilar proliferation, or budding are histological terms used to describe changes to the epidermal architecture. Applying these terms to RCM may enable more specific descriptions that are readily understood and disseminated, as they have already been widely adopted and defined in histopathology Although some studies have reported significant reductions in nucleated cells [ 11 , 25 , 29 ] and dendritic cells [ 8 , 12 ] our results did not indicate a reliable, significant change in those parameters.…”

“…In 2018, Ishioka et al described a reduction in the RCM parameters of nucleated polygonal cells and isolated keratinocytes with 5% fluorouracil treatment [ 11 ]. Pasquali et al monitored AK treatment with sequential cryotherapy and ingenol mebutate, identifying an atypical honeycomb pattern, round papillary vessels, parakeratosis, and stratum corneum detachment as reliable RCM parameters for response characterization [ 12 ]. In 2019, Benati et al identified a significant improvement of keratinocyte disarray, parakeratosis, and crust following topical imiquimod treatment [ 13 ].…”

Reflectance confocal microscopy in actinic keratosis—Comparison of efficacy between cryotherapy protocols

“…1,23 The aim of this study is to compare the effect of two cryotherapy application protocols through RCM, in order to evaluate the most effective way to perform the treatment of grade II AK. RCM has been used as a noninvasive imaging tool to provide quasi-histologic information about treatment effects, which can be useful to better understand the dynamics of freezing process and repair, 24,25 and to identify subclinical persistence after treatment.…”