(Background) Today, it istaken for granted that “Pemphigus” iscalled “天泡瘡” in Japanese, but the details are unknown. (Purpose and Methods) To elucidate this naming process, old Chinese and Japanese books were examined. In 211 books, mainly related to medicine, the presence or absence of “天疱瘡”, “天泡瘡,” or similar disease names, and if so, the descriptions were checked. (Result) (i) The first mention of “天疱瘡” is in the “Tankei shinpo” of 1347, which indicates a disease that causes skin erosions. The description of “天疱瘡” in this sense continued to be used until Qing Dynasty China. (ii) However, “Syphilis” was introduced to China. In 1513, “Syphilis” was first described as “楊梅瘡” or “木綿瘡” in “嶺南衛生方”, while “天疱瘡” was also mentioned. “天疱瘡” has since been used as a term for ‘Syphilis’ as well. (iii) Later, “黴毒” came to be used for “syphilis”, and “楊梅瘡” was no longer used. Asa result, “天疱瘡” became to be no longer used to refer to “Syphilis”. (iv) Around the same time, Ogata Koan translated a German book on internal medicine from the Dutch version, and translated “Pemphigus” as “天泡瘡”. Prior to this, the name “Pemphigus” had never been transmitted to Japan or China. (v) From the above, it can be said that Ogata Koan was the first to use “天泡瘡” as a translation of “Pemphigus”. Skin Research, 24 : 109-145, 2025

The present study aimed to evaluate the clinical efficacy and safety of mirogabalin for refractory post-herpetic neuralgia (PHN). The study population consisted of 24 patients aged 32-95 years with PHN. Significant reductions in mean pain visual analogue scale and mean Dermatology Life Quality Index (DLQI) scores were observed after 2 weeks of treatment with mirogabalin and were maintained up to 12 weeks. The majority of patients were not satisfied with their treatment before taking the drug, but about 90% were satisfied at the final visit. The therapeutic effect was achieved even at relatively low doses of 15-20 mg/day. This suggests that mirogabalin is a treatment option for refractory PHN. Although approximately 63% of the study population was older than 70 years, 22 of 24 patients (91.7%) were able to continue treatment. As the tolerability of mirogabalin was relatively high, it may be suitable for patients with refractory PHN who have difficulty increasing the dose of their existing medication due to side effects. Skin Research, 24 : 146-151, 2025

A 49-year-old woman was referred to our department with unknown fever and joint pain. We performed skin biopsies for suspected intravascular lymphoma. The first medical examination revealed a persistent, fist-sized, irregularly shaped, dark red plaque with scattered papules on the upper abdomen. Histologically, individual necrotic keratinocytes, either singly or in aggregates, were observed in the upper epidermis, including the horny layer. Furthermore, there was a perivascular infiltrate of neutrophils and lymphocytes in the superficial dermal plexus. Histopathological findings were consistent with nonspecific, persistent skin lesions typical of adult-onset Still’s disease. The diagnosis was confirmed based on negative antinuclear antibody, leukocytosis with neutrophilia, and elevated ferritin levels. Liver dysfunction was also observed, and disease activity was difficult to control. Individual necrotic keratinocytes, either singly or in aggregates, in the upper epidermis as well as superficial dermal infiltration of neutrophils are characteristic of nonspecific skin lesions in adult-onset Still’s disease. Dermatologists should be aware of these features. Skin Research, 24 : 152-156, 2025

A 56-year-old man was referred to our department with erythema and blisters on the trunk and limbs. We diagnosed linear IgA bullous dermatosis, based on the deposition of IgA along the dermoepidermal junction. We administered oral diaphenylsulfone ; however, new blisters appeared. He was admitted to our department for additional oral prednisolone administration. During hospitalization, thoracoabdominal computed tomography and upper and lower endoscopies were performed to search for malignant tumors. Although rectal vascular permeability was observed, it was not typical of ulcerative colitis. The dose of prednisolone was reduced on an outpatient basis, but exacerbation of blood in the stool and worsening of the skin rash occurred. After another lower endoscopy, ulcerative colitis was diagnosed. After the treatment of ulcerative colitis began, the rash subsided. Linear IgA bullous dermatosis is associated with ulcerative colitis, and ulcerative colitis often precedes the onset of the disease. In our case, linear IgA bullous dermatosis preceded the onset of ulcerative colitis. This sequence may have been obscured by the initiation of prednisolone treatment before the endoscopy, which masked the underlying condition. Skin Research, 24 : 157-161, 2025

A 19-year-old female was referred to our hospital because of the gradual enlargement of a subcutaneous mass that had appeared 7 years before her initial visit. She presented with a 3×3×3 cm-sized subcutaneous mass on the left occipital region with normal-colored and partly dark red-colored surface. Histopathological findings showed multinodular proliferation of epithelial cells and spindle-shaped cells from the dermis to subcutis, lymphocytic infiltration with lymphoid follicles, numerous voids containing erythrocytes, and perinodular fibrous change. Immunohistochemical staining was positive for CD99, CD68, EMA, and desmin, but negative for CD34. Fluorescence in situ hybridization suggested EWSR1-CREB1 gene rearrangement. This case was diagnosed as angiomatoid fibrous histiocytoma. Skin Research, 24 : 162-167, 2025

61-year-old male presented with a black macule onhis left great toe that had been present for 12 years. Recently, the lesion had enlarged and developed a central nodule. Dermoscopic examination revealed a parallel ridge pattern, and a skin biopsy confirmed the diagnosis of acral melanoma. Total excisionof the lesionwas performed with preservationof the affected toe, followed by skin grafting. Based on a diagnosis of stage IIB (pT4aN0M0) acral melanoma, postoperative adjuvant therapy with pembrolizumab (200 mg every three weeks) was initiated. At the second administration, the patient was aware of itching. At the sixth administration, he presented with irregularly shaped purplish-red papules on the trunk and extremities, which coalesced into plaques on the legs and feet. Dermoscopy demonstrated whitish striae. Histopathologically, the epidermis was irregularly thickened and accompanied by compact ortho-hyperkeratosis and hypergranulosis. The elongated rete ridges displayed a serrated pattern with hydropic degeneration. Civatte bodies were partially observed in the epidermis. A dense, band-like inflammatory infiltrate was present just beneath the epidermis. These findings led to a diagnosis of lichen planus, which was successfully treated with oral prednisolone. The patient was able to complete the 18 cycles of postoperative adjuvant therapy with pembrolizumab. The symptoms of lichen planus improved without discontinuation of amlodipine, suggesting that the eruption was a drug reaction induced by pembrolizumab. Although the significance of pembrolizumab-induced lichen planus remains unclear, the importance of maintaining primary disease treatment through appropriate management of immune-related adverse events is well recognized. Skin Research, 24 : 168-174, 2025

A 44-year-old woman underwent ovarian tumor laparoscopic surgery approximately 10 years earlier. Approximately 11 months prior to the initial consultation, she noticed a brownish-black papule in the umbilicus, corresponding to a scar from a biopsy performed by her previous physician. After 2 months, enlargement around the biopsy site with swelling and painful nodules during menstruation were noted, prompting referral to our department. At the first visit, a dome-shaped, dark red-to-black nodule approximately 11×10×4 mm was observed in the umbilicus. Abdominal magnetic resonance imaging revealed a 21 mm well-defined tumor in the umbilicus that exhibited low-signal intensity on T1 with punctate high-signal intensity, and heterogeneous high-signal intensity on T2. Total excision was performed under general anesthesia. No adhesions to the sheath or peritoneum were observed. Histopathologically, fibrous tissue proliferation was observed from the dermis to the subcutaneous tissue, containing numerous variably sized luminal structures. The luminal walls comprised a columnar epithelium resembling endometrial glands, with a pale pink amorphous substance within the lumen. Proliferation of endometrial stroma surrounding the lumen was observed, with no cellular atypia. ER and PgR were detected in luminal structures, whereas CD10 was detected in the endometrial stroma. We diagnosed umbilical endometriosis. Umbilical endometriosis is relatively rare and often presents with symptoms, such as pain coinciding with the menstrual cycle ; however, some cases may be asymptomatic. Rare cases of malignancy have been reported, emphasizing the importance of early detection for prompt treatment. Skin Research, 24 : 175-181, 2025

A 45-year-old woman presented with a subcutaneous nodule on her right forearm that had developed 20 years earlier. Physical examination revealed a brownish subcutaneous nodule of 15 mm in diameter on the right forearm. The subcutaneous nodule was resected and histologically diagnosed as proliferating trichilemmal tumor (PTT). PTT is a rare skin tumor that is more common in women than in men. More than 90% of PTT lesions arise on the scalp. Herein, we report a rare case of PTT on the right forearm. Although most PTTs are benign, there is a possibility of recurrence or malignant transformation ; thus, some researchers consider PTT as a malignancy. The mechanism of pathogenesis and malignant transformation of PTT remains to be elucidated. Further accumulation of data on PTT is needed to elucidate its pathogenesis and create clear guidelines for treatment. Skin Research, 24 : 182-186, 2025

We evaluated the clinical symptoms of 26 cases of mamushi (Gloydius blomhoffii) bites that were treated at our hospital over a period of about 10 years. Eight of 26 cases were administered antitoxic serum. The severity of mamushi bite symptoms is thought to be correlated with a rapid increase in creatine kinase (CK) levels. The patients that received early administration of antitoxic serum did not show markedly elevated CK, suggesting that the administration of antitoxic serum prevented the spread of toxin. In some cases that did not receive antitoxic serum, ocular symptoms, such as diplopia, developed, and CK levels were markedly elevated. There were no cases of organ failure requiring intensive care. Since swelling worsened after hospitalization in many cases, early administration of antitoxic serum should be considered, with careful monitoring for allergic reactions. There is no established method for the treatment of mamushi bites. It is often difficult to predict severity based on clinical findings and laboratory data at initial presentation. We found that patients tended not to become severe if they remained in Grade I for about one hour after the injury, suggesting that this could be an indicator for predicting severity. In general, administration of antitoxic serum is recommended for Grade III and above ; however, anaphylaxis and other side effects are concerns. The decision to administer antitoxin serum should be made comprehensively, based on careful monitoring of the clinical course in each individual case. Skin Research, 24 : 187-191, 2025

A 74-year-old woman was stung on the fingers by a bee after handling a bamboo broom. The pain subsided in about 30minutes and her general condition was not affected. The day after the bee sting, she visited our department with slight erythema on her fingers. She brought the bee with her, and it was identified as a female Xylocopa tranquebarorum. Blood tests at the initial visit showed honeybee-specific IgE at class 0; however, one month later, it had increased to class 2, suggesting that the sting stimulated honeybee-specific IgE production. X. tranquebarorum is a non-native bee that nests in dead bamboo. This bee has been expanding its distribution in Japan in recent years and is widely distributed from the Kanto to Chugoku regions, centering on the Tokai and Kinki regions, and can be found in urban areas. It is necessary to be careful when touching bamboo products, as stings by X. tranquebarorum can cause anaphylaxis. Skin Research, 24 : 192-197, 2025

A 56-year-old Japanese man was referred to our hospital because of a subcutaneous nodule with significant tenderness on his left forearm that had developed 10 years earlier. His symptoms completely resolved with surgical treatment. Histopathological examination revealed glomus cells with round nuclei and acidophilic cytoplasm that were densely proliferating. Immunohistochemical staining revealed positivity for vimentin and α-SMA, and negativity for S-100 protein, desmin, and CD34. We diagnosed glomus tumor. Since glomus tumors typically arise in the subungual region, diagnosing them can be challenging when they occur in atypical locations outside of this area. The most common sites outside the subungual region are the arms (40%), legs (26%), and trunk (20%). Histopathologically, the subcutaneous nodule comprised two distinct tumor components : glomus tumor proper, which is predominantly composed of a proliferation of glomus cells ; and glomangioma, which is composed of a proliferation of dilated blood vessels. The present case represented a relatively rare case of a mixed-type tumor. Magnetic resonance imaging is a useful auxiliary diagnostic tool for glomus tumors. Therefore, if a patient experiences pain in subcutaneous soft tissues outside of the fingers, it is important to consider proactive imaging tests. Skin Research, 24 : 198-203, 2025

A 63-year-old woman presented with a gradually enlarging, hard, subcutaneous tumor in the left preauricular area that had been present for nine months. Magnetic resonance imaging revealed a tumor in the left parotid gland. A punch biopsy was unable to reach the deeply situated tumor, preventing a definitive diagnosis from being made. The tumor, a well-demarcated encapsulated mass, was completely excised from the superficial lobe of the parotid gland. Pathological examination revealed that the tumor was primarily composed of tubular and bilayer glandular structures, with some cribriform structures and perineural infiltration. Immunohistochemical staining revealed that the inner cells were positive for epithelial membrane antigen and C-kit, whereas the outer cells were positive for α-smooth muscle actin and calponin. The Ki-67 labeling index was ＞20%. MYB gene rearrangement was observed. These clinical and pathological findings led to a diagnosis of salivary adenoid cystic carcinoma (ACC), a relatively rare malignant tumor. Unlike its cutaneous counterpart, primary salivary ACC generally has a poor prognosis. Long-term follow-up of patients with salivary ACC is required to monitor for tumor recurrence. Skin Research, 24 : 204-210, 2025