Bottomley, W W, and W J Cunliffe. “Severe Flares of Acne Following Isotretinoin: Large Closed Comedones (macrocomedones) Are a Risk Factor”. Acta Dermato-Venereologica 73, no. 1 (February 1, 1993): 74. Accessed May 24, 2026. https://medicaljournalssweden.se/actadv/article/view/16472.