Periorbital Acquired Dermal Macular Hyperpigmentation: A Distinctive Clinical Entity in Young Adults-Observational Case-Control Study.

Introduction Acquired dermal hyperpigmentation (ADMH) presenting on periorbital region has been described as individual case reports. We tried to characterize the features of periorbital ADMH. Materials and Methods This was a retrospective case-control study among our patients who attended the pigmentary clinic during January 2016-December 2017. Clinical, dermoscopic, and histopathological features of subjects who were recruited during the study period were prospectively evaluated. Results Total 19 subjects (11%) were identified among 177 ADMH patients. Periorbital ADMH patients had a relatively younger age of onset (23.26 ± 11.06 vs. 36.16 ± 13.41, P < 0.001). Dermoscopy of early periorbital ADMH showed only imperceptible speckled blue-gray dots that accentuated at outer-corner creases of eyes (the "outer-corner crease sign"). Clinicopathological features and prognosis of periorbital ADMH were similar to that of ADMH per se. Conclusion Periorbital ADMH should be considered as a differential diagnosis of periorbital hyperpigmentation in children and young adults. Outer-corner crease sign on dermoscopy may help to rule out other differentials in its early presentation.