Research Landscape of Acquired Dermal Macular Hyperpigmentation: A Bibliometric Analysis

Background: Acquired dermal macular hyperpigmentation (ADMH) includes lichen planus pigmentosus (LPP), ashy dermatosis (erythema dyschromicum perstans), and Riehl's melanosis (pigmented contact dermatitis/pigmented cosmetic dermatitis). The conditions that make up ADMH overlap in clinical and histopathological features. Objective: To conduct a bibliometric analysis to identify the top 100 most cited publications in ADMH. Methods: A Web of Science search was conducted on September 18, 2024, using the search terms "lichen planus pigmentosus," "ashy dermatosis," "erythema dyschromicum perstans," "riehl melanosis," "pigmented cosmetic dermatitis," "pigmented contact dermatitis," "acquired dermal macular hyperpigmentation," or "acquired macular pigmentation of unknown aetiology" in the title or abstract of articles published between 1998 and 2024. The search was filtered to include articles, letters, reviews, and editorials in English. Data collected included title, author, publication year, times cited, journal of publication, affiliations, and country of origin. The top 100 most cited publications were ranked based on annual citation score. Results: The top 100 most cited publications consisted of 62 articles, 24 letters (i.e., letter to the editor and comments), 8 editorials, and 6 reviews published between 1998 and 2023. The most articles were published in 2018 with 14 publications. The top contributing journals were the International Journal of Dermatology (n = 15, 15%) and the Journal of the European Academy of Dermatology and Venereology (n = 14, 14%). India, South Korea, and the United States contributed the most publications (n = 61, 61%) on ADMH (32, 17, and 12, respectively). India also led in having the top three corresponding authors, Muthu Sendhil Kumaran (n = 8, 8%), Keshavamurthy Vinay (n = 4, 4%), and Vinod Kumar Sharma (n = 3, 3%). Conclusion: This bibliometric analysis reveals a geographical concentration in ADMH research, emphasizing the need for increased research on these conditions with more global representation in future studies.