Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2022;12(4):e2022141 1 Erythema Multiforme: a Clinico- Dermoscopic-Histopathological Correlation of Evolving Targetoid Lesions Shreya Deoghare1, Devayani Pol1 1 Department of Dermatology, Venerology and Leprosy, Patil Medical College and Hospital & Research Centre, Pune, India Citation: Deoghare S, Pol D. Erythema multiforme: A clinico-dermoscopic-histopathological correlation of evolving targetoid lesions. Dermatol Pract Concept. 2022;12(4):e2022141. DOI: https://doi.org/10.5826/dpc.1204a141 Accepted: March 7, 2022; Published: October 2022 Copyright: ©2022 Deoghare 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: Shreya Deoghare, Department of Dermatology, Venerology and Leprosy, Dr. D. Y. Patil Medical College and Hospital & Research Centre, Sant Tukaram Nagar, Pimpri, Pune, India – 411018 Ph No: +91- 9325307311, E-mail: shreyadeoghare@yahoo.co.in Case presentation A 32-year-old male was diagnosed with recurrent erythema multiforme secondary to orolabial herpes. Dermoscopy ( polarised light, Dermlite DL4) of evolving targetoid lesions is shown in Figure 1. Teaching point The central ruptured vesicle is seen as a central circular yellowish-pink area on dermoscopy and correlates with subepidermal split on histopathology. The black pigmenta- tion is seen as brown-black colored dots and clods on der- moscopy and correlates with necrotic keratinocytes along dermo-epidermal junction on histopathology. A well-defined urticaria-like erythematous plaque is seen on dermoscopy as structureless homogenous pink-white area obliterating the normal pigment network and correlates with papillary oedema on histopathology. We discovered that, in the absence of treatment, the size of individual lesions increases as the time since the onset of the lesion increases. This is associated with dermoscopic feature of increase in the number and density of black-brown dots and clods, that we have termed as "splash of ink" appear- ance in fully evolved targetoid lesions, which could indicate ongoing damage to basal keratinocytes and melanocytes and thus disease activity. Dermoscopy can be used to determine the relative age of targetoid lesions. The size of the targetoid 2 Image Letter | Dermatol Pract Concept. 2022;12(4):e2022141 lesion and the size of “splash of ink” appearance indicates the evolution of the individual lesion. Targetoid lesions with the earliest onset will have largest size and “splash of ink” appear- ance and vice-versa. We believe that regardless of the cause of EM, its morphological appearance will be consistent in all cases, and treatment will result in fading of “splash of ink” ap- pearance. However, further studies are needed to validate this. References 1. Trayes KP, Love G, Studdiford JS. Erythema Multiforme: Recog- nition and Management. Am Fam Physician. 2019;100(2):82-88. PMID: 31305041. 2. Kaliyadan F. Dermoscopy of erythema multiforme. Indian Der- matol Online J. 2017;8:75. DOI: 10.4103/2229-5178.198771. PMID: 28217488. PMCID: PMC5297286. Figure 1. (A) A 32-year-old male presented with erythema multiforme presented with multiple targetoid lesions (white arrow) and post-inflammatory hyperpigmented patches (green arrow). Dermoscopy (polarised light, Dermlite DL4) of targetoid lesions of erythema multiforme: newest lesion - onset one day back (B), onset two days back (C) and oldest lesion - onset three days back (D). Yellow arrow: Central circular yellowish-pink area, black arrow: Brown-black colored dots and clods clustered regularly at center with irregular distribution at periphery, red arrow: Structureless homogenous pink-white area obliterating normal pigment network, blue arrow: pigmented reticular lines (pigment network) of normal skin.