Laser-Induced Koebner-Related Skin Reactions: A Clinical Overview.

The Koebner phenomenon (KP), also known as the isomorphic response, describes the process by which new lesions that are clinically and histologically identical to a patient's existing skin disease develop following trauma. Many skin diseases exhibit this characteristic, with variations that include possible, questionable, and pseudo-Koebner reactions, with the latter category occurring due to infectious agents seeding at a trauma site. Laser application, a type of controlled skin injury used for improving cutaneous lesions and skin rejuvenation, is also considered a form of trauma. This raises the question of whether controlled thermal injury can be regarded as a type of mechanical trauma capable of producing Koebner-related reactions. We conducted a literature review of cases or studies to identify laser-induced dermatoses that correspond to Koebner-related or pathergy reaction categories. As a whole, we identified nine case reports on true KPs, two cases on possible KPs, seventeen cases on laser-induced questionable KPs comprising cases of vasculitis, eczema or Meyerson reactions, and eruptive squamous atypia cases (ESA) as well as two pseudo-Koebner cases involving wart occurrences at laser application sites. Laser-induced Koebner reactions highlight several aspects of the KP. Firstly, the type of mechanical damage influences disease promotion, as different lasers are associated with different KPs. For example, hair removal lasers are linked with true and questionable KPs such as vasculitis while resurfacing lasers were found to be more connected with ESA occurrence. Secondly, the laser target is significant, with vascular laser application for port-wine stains tending to result in eczematous reactions, while hair follicle destruction can frequently lead to true KPs. Thirdly, the number of sessions matters; true KPs and eruptive squamous atypia questionable KPs typically appear after one to two sessions, whereas eczematous reactions require more sessions (at least four). Additionally, skin phototype is crucial, with darker phototypes showing a higher KP frequency as laser treatment for hypertrichosis relies on melanin absorption in the hair bulge or bulb for follicle destruction, as chromophore competes with the abundant melanin in the epidermis. Further research with larger-scale studies into trauma-specific Koebner reactions is vital for refining treatment protocols, minimizing post-laser adverse effects, and improving dermatological care outcomes.

Can Artificial Intelligence "Hold" a Dermoscope?-The Evaluation of an Artificial Intelligence Chatbot to Translate the Dermoscopic Language.

This survey represents the first endeavor to assess the clarity of the dermoscopic language by a chatbot, unveiling insights into the interplay between dermatologists and AI systems within the complexity of the dermoscopic language. Given the complex, descriptive, and metaphorical aspects of the dermoscopic language, subjective interpretations often emerge. The survey evaluated the completeness and diagnostic efficacy of chatbot-generated reports, focusing on their role in facilitating accurate diagnoses and educational opportunities for novice dermatologists. A total of 30 participants were presented with hypothetical dermoscopic descriptions of skin lesions, including dermoscopic descriptions of skin cancers such as BCC, SCC, and melanoma, skin cancer mimickers such as actinic and seborrheic keratosis, dermatofibroma, and atypical nevus, and inflammatory dermatosis such as psoriasis and alopecia areata. Each description was accompanied by specific clinical information, and the participants were tasked with assessing the differential diagnosis list generated by the AI chatbot in its initial response. In each scenario, the chatbot generated an extensive list of potential differential diagnoses, exhibiting lower performance in cases of SCC and inflammatory dermatoses, albeit without statistical significance, suggesting that the participants were equally satisfied with the responses provided. Scores decreased notably when practical descriptions of dermoscopic signs were provided. Answers to BCC scenario scores in the diagnosis category (2.9 ± 0.4) were higher than those with SCC (2.6 ± 0.66, p = 0.005) and inflammatory dermatoses (2.6 ± 0.67, p = 0). Similarly, in the teaching tool usefulness category, BCC-based chatbot differential diagnosis received higher scores (2.9 ± 0.4) compared to SCC (2.6 ± 0.67, p = 0.001) and inflammatory dermatoses (2.4 ± 0.81, p = 0). The abovementioned results underscore dermatologists' familiarity with BCC dermoscopic images while highlighting the challenges associated with interpreting rigorous dermoscopic images. Moreover, by incorporating patient characteristics such as age, phototype, or immune state, the differential diagnosis list in each case was customized to include lesion types appropriate for each category, illustrating the AI's flexibility in evaluating diagnoses and highlighting its value as a resource for dermatologists.

Multiple Keratoacanthoma-like Syndromes: Case Report and Literature Review.

Keratoacanthoma (KA) is a fast-growing skin tumor subtype that can be observed as a solitary lesion or rarely as multiple lesions in the context of rare genetic syndromes. Syndromes with multiple keratoacanthoma-like lesions have been documented as multiple self-healing squamous epithelioma (Ferguson-Smith syndrome), eruptive keratoacanthoma of Grzybowski, multiple familial keratoacanthoma of Witten and Zak Muir-Torre syndrome, and incontinentia pigmenti. The treatment approach of those entities is challenging due to the numerous lesions, the lesions' undefined nature, and the co-existence of other malignant skin tumors. Herein, we report a case of a 40-year-old woman who developed multiple treatment-resistant Ferguson-Smith-like keratoacanthomas with a co-existing large and ulcerated invasive squamous cell carcinoma and microcystic adnexal carcinoma on the scalp. Multiple keratoacanthomas on her extremities were successfully treated with oral acitretin (0.5 mg/kg/day) in combination with topical Fluorouracil (5-FU) 5%, while excision and plastic surgery restoration were performed to treat the ulcerated cancer lesion on her scalp. Due to the interesting nature of this rare syndrome, we performed a literature review including case reports and case series on multiple-KA-like lesions syndromes and focusing on diagnosis and therapy approaches. We also conducted a comparison of patient reports, which included assessing the clinical appearance of the lesions and evaluating the success and progress or the failure of various treatment approaches that were implemented.

Race-Specific and Skin of Color Dermatoscopic Characteristics of Skin Cancer: A Literature Review.

INTRODUCTION: Individuals with melanin-rich skin account for the majority of the world's population. However, literature data regarding dermatoscopic characteristics of skin cancer in skin of color (SoC) are scarce. The dermatoscopic characteristics of cutaneous tumors might differ among skin types due to heterogeneity in composition and pigmentation. OBJECTIVES: To summarize literature data on the dermatoscopic findings of skin neoplasms, according to the skin color and race. METHODS: The literature search was performed using PubMed database up to December 30, 2022 and was conducted with the use of terms referring to dermatoscopy, race (Caucasians, Hispanics, Asians, and Black/African) and skin cancer types (BCC, SCC, keratoacanthoma, Bowen's disease and melanoma). RESULTS: In total, 30 race-specific records were included. 9 SoC records for BCCs (2 BCC studies in Hispanics, 1 BCC study in Black individuals and 6 BCC studies in Asians ), 9 SoC records for SCCs ( 1 SCC study in Hispanics, 1 SCC study in Black individuals and 7 SCCs in Asian population) and 8 SoC records for melanoma (2 melanoma studies in Hispanics, 1 melanoma study in Blacks and 5 melanoma studies in Asians) were compared with 4 records that involved only Caucasian population, according to their participant section as well as with studies on dermatoscopy characteristics without focusing on race origins and phototype of the patient. In Hispanics and in both fair and dark-skinned Asians, BCCs were more often pigmented or at least with pigmented structures on dermoscopy. Squamous cell carcinoma (SCC) and keratoacanthoma were the least studied in SoC patients. Bowen's disease in SoC patients can be pigmented in a higher frequency compared to Caucasians, with glomerular vessels and a squamous surface being the most common dermatoscopic findings. The most frequent pattern of melanomas in SoC individuals were the parallel ridge pattern in palmoplantar region. CONCLUSION: Based on a review of studies including Caucasians, Hispanics, Asians and Blacks /Africans, SoC patients present with more frequent and unique dermatoscopy features of skin cancers.

Non-Melanoma Skin Cancer and Vitamin D: The "Lost Sunlight" Paradox and the Oxidative Stress Explanation.

UV radiation (UVR) is responsible for inducing both harmful and beneficial effects on skin health. Specifically, it has been reported to disrupt oxidant and antioxidant levels, leading to oxidative stress conditions in skin tissue. This phenomenon might trigger photo-carcinogenesis, resulting in melanoma, NMSC (non-melanoma skin cancer), such as BCC (basal cell carcinoma) and SCC (squamous cell carcinoma), and actinic keratosis. On the other hand, UVR is essential for the production of adequate vitamin D levels, a hormone with important antioxidant, anticancer and immunomodulatory properties. The exact mechanisms implicated in this two-fold action are not well understood, as there still no clear relation established between skin cancer and vitamin D status. Oxidative stress seems to be a neglected aspect of this complex relation, despite its role in both skin cancer development and vitamin D deficiency. Therefore, the aim of the present study is to examine the correlation between vitamin D and oxidative stress in skin cancer patients. A total of 100 subjects (25 with SCC, 26 with BCC, 23 with actinic keratosis, and 27 controls) were assessed in terms of 25-hydroxyvitamin D (25(OH) D) and redox markers such as thiobarbituric acid reactive substances (TBARS), protein carbonyls, total antioxidant capacity (TAC) in plasma, glutathione (GSH) levels and catalase activity in erythrocytes. The majority of our patients revealed low vitamin D levels; 37% of the subjects showed deficiency (<20 ng/mL) and 35% insufficiency (21-29 ng/mL). The mean 25(OH) D level of the NMSC patients (20.87 ng/mL) was also found to be significantly lower (p = 0.004) than that of the non-cancer patients (28.14 ng/mL). Furthermore, higher vitamin D levels were also correlated with lower oxidative stress (positive correlation with GSH, catalase activity TAC index and negative correlation with TBARS and CARBS indices). NMSC patients diagnosed with SCC showed lower catalase activity values compared to non-cancer patients (p < 0.001), with the lowest values occurring in patients with a chronic cancer diagnosis (p < 0.001) and vitamin D deficiency (p < 0.001). Higher GSH levels (p = 0.001) and lower TBARS levels (p = 0.016) were found in the control group compared to the NMSC group, and to patients with actinic keratosis. Higher levels of CARBS were observed in patients with SCC (p < 0.001). Non-cancer patients with vitamin D sufficiency showed higher TAC values compared to non-cancer patients with vitamin D deficiency (p = 0.023) and to NMSC patients (p = 0.036). The above-mentioned results indicate that NMSC patients reveal increased levels of oxidative damage markers compared to control levels, while vitamin D status plays a critical role in the determination of individuals' oxidative status.