Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(3):e2024203 1 Hereditary Papulotranslucent Acrokeratoderma: How Dermoscopy Can Aid in Diagnosis Sara Mezzana1, Mariachiara Arisi1, Luca Bettolini1, Giulia Calabrese2, Piergiacomo Calzavara-Pinton1, Gaetano Licata3 1 Department of Dermatology, University of Brescia, Spedali Civili Brescia, Brescia, Italy 2 UOSD Dermatologia ASL Napoli 1 Centro, Napoli, Italy 3 Dermatology Unit, Ospedale S.A. Abate, Trapani, Italy Key words: hereditary papulotranslucent acrokeratoderma, diagnosis, dermoscopy Citation: Mezzana S, Arisi M, Bettolini L, Calabrese G, Calzavara-Pinton P, Licata G. Hereditary Papulotranslucent Acrokeratoderma: How Dermoscopy Can Aid in Diagnosis. Dermatol Pract Concept. 2024;14(3):e2024203. DOI: https://doi.org/10.5826/dpc.1403a203 Accepted: March 9, 2024; Published: July 2024 Copyright: © Mezzana 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: Sara Mezzana, Department of Dermatology, Spedali Civili, University of Brescia, Brescia, Italy. Tel +39 030 3995301 Fax +39 0303995015 E-mail: s.mezzana@unibs.it Introduction Hereditary papulotranslucent acrokeratoderma (HPA) is charac- terized by the presence of persistent, asymptomatic, yellowish- white translucent papules and plaques on the palms and soles that become more prominent upon exposure to water [1]. Case Presentation We present the case of an 18-year-old female who sought evaluation at the Dermatology Clinic due to asymptomatic, white, translucent papules on her palms. She observed a no- ticeable exacerbation of her palmar lesions following show- ers and physical activity. Our patient declined to undergo a cutaneous biopsy; however, her mother reported similar symptoms and consented to a biopsy, which histologically confirmed the diagnosis of HPA. Upon dermatological examination, conducted follow- ing transient water exposure, approximately 2-mm papules and plaques were found distributed bilaterally on the palms. Over time, these lesions progressed into plaques, exhib- iting additional features such as whitish edematous areas, thickening, and excessive wrinkling (Figure 1). The dermo- scopic evaluation revealed white papules covered by scales over a reddish background, primarily localized in the skin furrows and present inside an edematous ballooning area (balloon-like; Figure 2). Based on the clinical presentation, which demonstrated asymptomatic papular lesions intensi- fied by exposure to water and the family history, the patient was diagnosed with HPA. Treatment involved the application of topical exfo- liation agents such as topical salicylic acid 5% and reti- noic acid ointment once a day, resulting in significant effectiveness. 2 Research Letter | Dermatol Pract Concept. 2024;14(3):e2024203 Conclusion Two types of papulotranslucent acrokeratoderma have been reported in the medical literature: hereditary and transient reactive [1]. HPA is characterized by symmetrical, translu- cent, yellowish -white papules and plaques found mainly on the palms and soles. This condition of unknown etiology is usually worse when in contact with water and can occa- sionally extend to the soles. HPA typically affects females during puberty and is inherited in an autosomal dominant pattern [2]. Because the lesions occur primarily on the palms and soles, physical trauma may play a role in initiating this condition [2]. An important condition that needs to be ruled out is aquagenic palmar keratoderma, an acquired condition char- acterized by burning and edema limited to the hands after brief immersion in water. Dermoscopy of aquagenic palmar keratoderma shows large yellow well-defined globules not af- fecting dermatoglyphics or simply enlargement of the sweat duct pores when compared with a normal-looking palmar skin area [3]. However, in HPA, as illustrated in our descrip- tion, it is possible to observe white scales against a reddish Figure 1. Clinical photographs: papules and plaques distributed bilaterally on the palms, along with whitish edem- atous areas, thickening, and excessive wrinkling. Figure 2. The dermoscopic images depict white papules covered by scales against a reddish background (arrows), in addition to the presence of ballooning (balloon-like) areas (square). Research Letter | Dermatol Pract Concept. 2024;14(3):e2024203 3 background, primarily concentrated within the skin furrows. The presence of the ballooning (balloon-like) area in dermos- copy is a constant feature in this condition and represents the anatomopathological equivalent of acanthosis. The dermoscopic difference between palmoplantar aquagenic keratoderma and HPA can help distinguish these clinically similar conditions, eliminating the necessity for a skin biopsy, although it remains the gold standard for diagnosis. Specific treatments for HPA are not usually necessary because the condition is generally asymptomatic. HPA treat- ment is mainly topical and often involves exfoliation agents, including topical urea, salicylic acid, and ammonium, which can be used combined with oral administration of acitretin [4]. Patients require further follow-up. References 1. Onwukwe MF, Mihm MC Jr, Toda K. Hereditary papulotrans- lucent acrokeratoderma. A new variant of familial punctate keratoderma? Arch Dermatol. 1973;108(1):108-110. doi:10.1001 /archderm.108.1.108 2. Sracic JK, Krishnan RS, Nunez-Gussman JK, Orengo IF, Hsu S. Hereditary papulotranslucent acrokeratoderma: a case report and literature review. Dermatol Online J. 2005;11(3): 3. Errichetti E, Stinco G. Dermoscopy in General Dermatology: A Practical Overview.  Dermatol Ther (Heidelb). 2016;6(4): 471-507. doi:10.1007/s13555-016-0141-6 4. Sun Y, Jia H. Hereditary papulotranslucent acrokeratoderma: a simultaneous presentation in daughter and mother.  Indian J Dermatol Venereol Leprol. 2013;79(4):555. doi:10.4103/0378 -6323.113114