Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(3):e2024197 1 Dermoscopic Findings in Juvenile Colloid Milium Karama Sboui1,2, Noureddine Litaiem1,2, Soumaya Rammeh1,3, Faten Zeglaoui1,2 1 Faculty of Medicine, Tunis El Manar University, Tunis, Tunisia 2 Department of Dermatology, Charles Nicolle Hospital, Tunis, Tunisia 3 Department of Pathology, Charles Nicolle Hospital, Tunis, Tunisia Key words: juvenile colloid milium, ultraviolet (UV) light susceptibility, hereditary predisposition, translucent papules, dermoscopy Citation: Sboui K, Litaiem N, Rammeh S, Zeglaoui F. Dermoscopic Findings in Juvenile Colloid Milium. Dermatol Pract Concept. 2024;14(3):e2024197. DOI: https://doi.org/10.5826/dpc.1403a197 Accepted: February 27, 2024; Published: July 2024 Copyright: © Sboui et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Karama Sboui, M.D, Charles Nicolle Hospital, Bd du 9 Avril 1938, Tunis, Tunisia. Telephone: +21693988116 Email: Karamasboui1@gmail.com Introduction Juvenile colloid milium (JCM) is an extremely rare condi- tion characterized by the development of translucent pap- ules in sun-exposed areas during childhood [1]. While the exact etiology remains unknown, studies suggest a potential autosomal inheritance of sun-induced keratinocyte damage susceptibility [2]. Familial cases have been reported [3]. In this paper, we describe a new case of familial JCM with an emphasis on dermoscopic findings. Case Presentation A 15-year-old boy from a rural area presented with multi- ple mildly pruritic facial papules that appeared at the age of 10 and gradually became pronounced. His parents were consanguineous, and his sister and paternal aunt had sim- ilar symptoms. Physical examination revealed numerous small firm translucent papules on his face and amber-brown papules on the dorsum of his hands (Figure 1). Dermoscopy showed well-defined structureless isolated or clustered translucent-white clods with a distinct white collarette, along with a faint brownish pigment pseudo-network (Figure 2). A biopsy taken from the dorsum of his hand showed acanthosis of the epidermis, with islands of amorphous eosinophilic material in the papillary dermis (Figure 2). No grenz zone was observed. The amorphous colloid material was positive with periodic acid-Schiff (PAS), and Congo red staining was negative. In the adjacent dermal papillae, elastic fibers did not show actinic damage. The clinical and histo- pathological findings were consistent with the diagnosis of familial JCM. Photoprotection measures were advised. Discussion Colloid milium (CM) is a disorder characterized by the accu- mulation of amorphous material in the dermis. JCM is a rare form of CM that typically appears before puberty [1]. It was linked to the degeneration of ultraviolet (UV)-transformed ke- ratinocytes, suggesting a possible genetic photosensitivity [4]. 2 Research Letter | Dermatol Pract Concept. 2024;14(3):e2024197 Lesions often manifest as asymptomatic or mildly pruritic translucent, yellowish, or amber/brown papules, which may form clusters [1]. In our patient, dermoscopy showed dis- tinct structureless isolated or clustered translucent-white clods featuring a white collarette and a subtle brownish pigment pseudo-network in the background. Structureless translucent clods correspond to the amorphous eosinophilic islands observed in the upper dermis in histopathology. These amorphous deposits lie directly below the epidermis, without a narrow papillary dermal band (grenz zone) [2]. Solar elastosis is usually absent but may develop with age [1,2,4]. The pigmentary changes may likely be due to solar damage, considering the patient’s age (15 years) and regular sun exposure. JCM has been described in association with ligneous conjunctivitis and ligneous periodontitis [5]. This suggests a likely causal connection between these manifesta- tions, potentially representing different clinical presentations of a shared pathogenic process that affects both cutaneous and mucosal areas [5]. The management of JCM is not well codified. Photoprotection should be recommended for all patients. Conclusion In conclusion, JCM is a rare and probably underdiagnosed subtype of CM. Although benign, JCM can alter the pa- tient’s quality of life by posing an aesthetic detriment. Rais- ing awareness of this rare disease can lead to more cases being diagnosed and ultimately to the culprit gene(s) being identified. Figure 1. Clusters of translucent papules on the cheeks (A), nose (B), and lips (C, D). Brown amber papules on the dorsum of the hands (E, F). Research Letter | Dermatol Pract Concept. 2024;14(3):e2024197 3 References 1. Percival GH, Duthie DA. Notes on a case of colloid pseudom- ilium. Br J Dermatol Syph. 1948;60(12):399-404. doi:10.1111 /j.1365-2133.1948.tb10971.x 2. Hashimoto K, Nakayama H, Chimenti S, et al. Juvenile colloid mil- ium. Immunohistochemical and ultrastructural studies. J Cutan Pathol. 1989;16(3):164-174. doi:10.1111/j.1600-0560.1989 .tb00033.x 3. Martorell-Calatayud A, Balmer N, Sanmartin O, Botella- Estrada R, Requena C, Guillen-Barona C. Familial juvenile colloid milium: report of a well documented case.  J Am Acad Dermatol. 2011;64(1):203-206. doi:10.1016/j.jaad.2009.06.051 4. Handfield-Jones SE, Atherton DJ, Black MM, Hashimoto K, McKee PH. Juvenile colloid milium: clinical, histological and ultrastructural features.  J Cutan Pathol. 1992;19(5):434-438. doi:10.1111/j.1600-0560.1992.tb00617.x 5. Schuster V, Tefs K, Hügle B. Juvenile colloid milium and ligneous conjunctivitis are caused by severe hypoplasminogenemia—no evidence for causal relationship to non-Hodgkin’s lymphoma.  J Eur Acad Dermatol Venereol. 2006;20(10):1368. doi:10.1111 /j.1468-3083.2006.01722.x Figure 2. Dermoscopic examination reveals well-defined structureless translucent-white clods (A) with the presence of a white collarette (B, indicated by white arrows), often forming clusters (C, highlighted with a red circle). These clods are set against a faint brownish background (D). Histopathology showed eosinophilic material occupying the papillary dermis (E, Hematoxyline-eosin stain; original magnification x100). No grenz zone was noted (F, Hematoxyline-eosin stain; original magnification x200).