Oral isotretinoin in photoaging: objective histological evidence of efficacy and durability.

BACKGROUND: The off-label use of oral isotretinoin in photoaging is a therapeutic tool that has been used by dermatologists. There are few studies to corroborate its effectiveness and durability.

OBJECTIVES: To assess, both clinically and histologically, the changes caused by the use of oral isotretinoin in skin photoaging as well as the duration of the effects.

METHODS: 20 female patients, aged 45-50 years, with phototypes II-VI, none of whom had experienced menopause, were treated with 20mg oral isotretinoin, 3 days a week, for 12 weeks. They underwent clinical analysis and skin biopsies in the pre-auricular region, while histologic cuts enabled assessment of the solar elastosis level and morphologic analysis.

RESULTS: Clinically, patients, as well as the researching and the assessor physicians, noticed improvement in skin quality. One patient presented severe solar elastosis, 11 manifested the moderate form, while 8 presented the discreet type. According to histological analysis, 65% of the patients revealed alteration in the distribution and thickness of the elastic fibers, which can be interpreted as a histological improvement, while 60% showed an increase in collagen density. We observed an increase in collagen density, from 51.2% to 57.4%, (p=0.004). At the end of the 12-week follow-up period, this density decreased to 54.7% (p=0.050). There was an increase in the density of elastic fibers, from 26.5% to 31.3%, (p=0.02), which had dropped to 27.5% at the end of the 12-week follow-up period.

CONCLUSIONS: The study confirmed the role of oral isotretinoin in remodeling the extracellular matrix against photoaging, as well as its durability after 12 weeks, especially when we consider collagen fibers.