Targetoid hemosiderotic nevus (THN) is a rare variant of melanocytic nevus, characterized by a sudden development of a targetoid ecchymotic halo around a pre-existing nevus. THN clinically raises concern for malignant transformation due to its abrupt change in color and size. THN should be distinguished from other diseases showing a peripheral halo, including targetoid hemosiderotic hemangioma, halo nevus, and Meyerson nevus. Dermoscopy can help clinicians to differentiate THN from these diseases. The typical dermoscopic features of THN are known to be divided into two distinctive areas: the central melanocytic area and the peripheral ecchymotic area. In our case, dermoscopy revealed a novel bull’s eye pattern composed of a central area with characteristic features of benign melanocytic nevus, an intermediated white circular ring, and a peripheral milky red area. When a sudden change occurs in a pre-existing nodule showing targetoid features, dermoscopy should be considered before conducting a biopsy or surgical intervention.

Background: Lichenoid drug eruption (LDE) is a relatively rare form of cutaneous drug eruption and that resembles lichen planus on a clinical and histological basis. Although there are some studies on histopathological findings of LDE, studies on clinical findings of LDE are limited. Objective: To investigate the clinical and histopathologic findings and prognosis of LDE. Methods: We retrospectively investigated the clinicopathologic findings of LDE patients who visited Kosin University Gospel Hospital between 1990 and 2020. Results: This study included 44 LDE patients (male:female=1.4:1). The most common causative drug was anti-tuberculous drugs (52.3%), followed by 5-fluorouracil (11.4%), and captopril (9.1%). There were pruritic erythematous scaly or lichenoid patches and plaques in all cases. The most frequently involved sites were trunk and extremities. Notably, 15 cases (34.1%) involving the scalp and 3 cases (6.8%) involving the oral mucosa. Treatment modalities included oral, topical corticosteroid, and oral antihistamines. Among 44 cases, 28 patients discontinued the causative agent, and 16 patients continued to use it after diagnosis of LDE. The mean duration of treatment for patients who discontinued or did not discontinue the causative drugs was 4, 10 weeks, respectively. The most commonly observed histopathologic findings were superficial and deep perivascular infiltration of inflammatory cells (100.0%) and eosinophil infiltration (93.2%). Conclusion LDE can be differentiated from idiopathic lichen planus by clinicopathologic findings. LDE appears to be a mild form of drug eruption in which symptoms can be controlled with conservative treatment, even without the cessation of causative drugs for the treatment of the underlying disease.

Background: The etiology and pathogenesis of lichen planus (LP) are not fully understood. Several studies have reported varying prevalence of anti-hepatitis C virus antibody (anti-HCV Ab) in LP. The relationship between LP and HCV infection remains controversial. Objective: To investigate the relationship between LP and HCV infection in Busan and Gyeongnam, Korea. Methods: We reviewed the medical records of 84 outpatients with LP and 84 control subjects (age- and sex-matched) from 2000 to 2020. Data on age, sex, duration of disease, distribution, shape, systemic diseases, and serology of anti-HCV Ab were collected. Results: The prevalence of anti-HCV Ab was 1.2% and 9.5% in the control group and patients with LP, respectively. Compared with the control group, patients with LP had a higher risk of HCV infection with an odds ratio of 8.737 (p=0.034). The mean duration of disease for the eight patients with HCV-associated LP was 5.8 months, which was shorter than 15.8 months in 84 patients with LP alone. Mucosal erosive LP was observed most frequently in HCV-associated LP with an odds ratio of 9.273 (p=0.003). Conclusion HCV infection may be clinically relevant to the development of LP. Furthermore, HCV infection may accelerate the progression of LP and is possibly related to the mucosal erosive subtype. Therefore, dermatologists should perform an anti-HCV Ab screening test for patients with LP, disclosing the potential association between LP and HCV infection.

Background: The etiology and pathogenesis of lichen planus (LP) are not fully understood. Several studies have reported varying prevalence of anti-hepatitis C virus antibody (anti-HCV Ab) in LP. The relationship between LP and HCV infection remains controversial. Objective: To investigate the relationship between LP and HCV infection in Busan and Gyeongnam, Korea. Methods: We reviewed the medical records of 84 outpatients with LP and 84 control subjects (age- and sex-matched) from 2000 to 2020. Data on age, sex, duration of disease, distribution, shape, systemic diseases, and serology of anti-HCV Ab were collected. Results: The prevalence of anti-HCV Ab was 1.2% and 9.5% in the control group and patients with LP, respectively. Compared with the control group, patients with LP had a higher risk of HCV infection with an odds ratio of 8.737 (p=0.034). The mean duration of disease for the eight patients with HCV-associated LP was 5.8 months, which was shorter than 15.8 months in 84 patients with LP alone. Mucosal erosive LP was observed most frequently in HCV-associated LP with an odds ratio of 9.273 (p=0.003). Conclusion HCV infection may be clinically relevant to the development of LP. Furthermore, HCV infection may accelerate the progression of LP and is possibly related to the mucosal erosive subtype. Therefore, dermatologists should perform an anti-HCV Ab screening test for patients with LP, disclosing the potential association between LP and HCV infection.

Spark’s nevus is a compound word composed of Spitz nevus and Clark’s nevus. It is one of the combined melanocytic nevi which is more common in female and usually presents as a sharp circumscribed hyperpigmented macule on the lower extremities. On histopathologic findings, both cytologic features of Spitz nevus characterized as large spindle or epithelioid melanocytes containing large nuclei with abundant cytoplasm, and architecture of Clark’s nevus characterized as elongation of rete ridges, bridging of the nests, concentric and lamellar fibrosis can be seen. A 24-year-old female presented with an asymptomatic, solitary, dark-brown-colored papule surrounded by brownish patch that looked similar to dysplastic nevus or malignant melanoma on the buttock. On dermoscopic examination, it showed brown-to-black globules, diffuse homogenous pigmentation with blue-white structures, and a surrounding brownish reticular pattern that faded away. On histopathologic findings, overall asymmetrical structure, epithelioid large melanocytes containing large nuclei with abundant cytoplasm, and Kamino body were seen in the central portion. Also, lentiginous hyperplasia, bridging of the nests composed of melanocytes containing foamy cytoplasm, concentric and lamellar fibrosis along with the elongation of rete ridge, and perivascular lymphocytic infiltration were seen in the peripheral portion. The diagnosis of Spark’s nevus was made. Following its definition, this combined nevus is diagnosed histopathologically, but the clinicodermoscopic features have not been well described. Herein, we report a case of Spark’s nevus in which dermoscopy was helpful for differentiating it from malignant melanoma.

Arthonia dokdoensis sp. nov., a lichenicolous fungus from the subcosmopolitan Arthonia molendoi complex growing on crustose thalli of species of the genus Orientophila (subfamily Xanthorioideae, Teloschistaceae), as well as the lichen species Rufoplaca toktoana sp. nov. (subfamily Caloplacoideae, Teloschistaceae) similar to Rufoplaca kaernefeltiana, both from Dokdo Islands, Republic of Korea, are described, illustrated, and compared with closely related taxa. In the phylogenetic tree of the Arthoniaceae based on 12S mtSSU and RPB2 gene sequences, the phylogenetic position of the A. dokdoensis and the relationship with the A. molendoi group are illustrated, while the position of the newly described R. toktoana is confirmed by phylogenetic tree based on ITS nrDNA data.

A total of 121 species of lichens belonging to the genus Arthothelium have been described to date, most of which have been found in tropical regions. Here, we describe the discovery of a novel Arthothelium species for the first time in South Korea. Until now, Arthothelium ruanum was the only Arthothelium species reported in South Korea. Among the 113 specimens collected in this study, we identified A. ruanum and a putative new species, Arthothelium punctatum (J. S. Park & J.–S. Hur, sp. nov.). The diagnostic characters of A. punctatum are as follows: apothecia punctate, shortly elongate to branched, small, 0.1–0.2 mm wide, hypothecium hyaline to pale brown and obovate to broadly ellipsoid, muriform ascospores, 29.5–44.6 × 12.2–18.2 μm. The new species was found in Mt. Seokbyeong at an altitude of 790 m on smooth bark. Upon phylogenic analysis, the putative new species, A. punctatum, was separated from other Arthothelium species although the specimens analyzed were clustered with Arthoniaceae in phylogenetic trees based on both the mitochondrial small subunit (mtSSU) sequence and combined mtSSU and nuclear ribosomal large subunit sequences. Our data clearly indicate that this species is a new species belonging to the family Arthoniaceae. To elucidate the taxonomic characteristics of the new species, we provide morphological descriptions and a distribution map.
Altitude ; Classification ; Humans ; Hyalin ; Korea* ; Lichens* ; Trees

Three monophyletic branches are strongly supported in a phylogenetic analysis of the Teloschistaceae based on combined data sets of internal transcribed spacer and large subunit nrDNA and 12S small subunit mtDNA sequences. These are described as new monotypic genera: Jasonhuria S. Y. Kondr., L. Lokos et S. -O. Oh, Loekoesia S. Y. Kondr., S. -O. Oh et J. -S. Hur and Olegblumia S. Y. Kondr., L. Lokos et J. -S. Hur. Three new combinations for the type species of these genera are proposed.
Dataset ; DNA, Mitochondrial ; Lichens*

Lichen studies, including biodiversity, phylogenetic relationships, and conservation concerns require definitive species identification, however many lichens can be challenging to identify at the species level. Molecular techniques have shown efficacy in discriminating among lichen taxa, however, obtaining genomic DNA from herbarium and fresh lichen thalli by conventional methods has been difficult, because lichens contain high proteins, polysaccharides, and other complex compounds in their cell walls. Here we report a rapid, easy, and inexpensive protocol for extracting PCR-quality DNA from various lichen species. This method involves the following two steps: first, cell breakage using a beadbeater; and second, extraction, isolation, and precipitation of genomic DNA. The procedure requires approximately 10 mg of lichen thalli and can be completed within 20 min. The obtained DNAs were of sufficient quality and quantity to amplify the internal transcribed spacer region from the fungal and algal lichen components, as well as to sequence the amplified products. In addition, 26 different lichen taxa were tested, resulting in successful PCR products. The results of this study validated the experimental protocols, and clearly demonstrated the efficacy and value of our KCl extraction method applied in the fungal and algal samples.
Biodiversity ; Cell Wall ; DNA* ; Fungi ; Lichens* ; Polymerase Chain Reaction ; Polysaccharides