Confusing acquired macular pigmentation of unknown etiology in children: Retrospective analysis of 10 years in single tertiary center

Acquired Macular Hyperpigmentation: Ashy dermatosis (AD), lichen planus pigmentosus (LPP), erythema dyschromicum perstans (EDP), and idiopathic eruptive macular pigmentation (IEMP) are the spectrum of acquired macular pigmentation of unknown etiology (MPUE). The aim of this study is to investigate and reevaluate our pediatric patients who had clinically and histopathologically been diagnosed with aforementioned disorders, in consideration of the global consensus statement on acquired MPUE. Materials and Methods: A retrospective chart review of 23 pediatric cases that had applied to the dermatology unit between the years 2007 and 2017 and diagnosed with any of the acquired macular pigmentation was performed. Results: Of 23 patients, 16 were diagnosed with AD, 4 with LPP, and 3 with IEMP. In AD patients, major site of presentation at onset was the trunk (13/16) and brownish (15/16) were the most prominent coloring. Dermal melanophages (16/16), perivascular lymphohistiocytic infiltrate (14/16), and pigment incontinence (7/16) were the most prominent features. Upper limbs (3/4) were the most predilection area in LPP patients. Perivascular lymphohistiocytic (4/4), lichenoid infiltration (3/4), basal vacuolar degeneration (4/4), and dermal melanophages (4/4) were observed. The trunk was the major site of presentation (3/3) in IEMP patients. Brownish (2/3) and ashen-gray (1/3) was the coloring of lesions. Basal layer pigmentation (3/3) and dermal melanophages (3/3) were the most prominent findings. No basal vacuolar changes (0/3) were observed. Conclusion: Clinical and histopathological distinction between these conditions is challenging. We reevaluated our patients in this context. We predict that we have achieved more accurate terminology with the global consensus statement. Such a terminology might allow that these disorders may be compared with a collective terminology in the literature.