Three years earlier, a 37-year-old woman underwent resection for right Knuck’s canal edema under general anesthesia. Resection was successful, but after extubation, erythema and hypotension appeared. Rocuronium, a muscle relaxant that was administered intraoperatively, and sugammadex, a muscle relaxant antagonist, were suspected to be causative agents of the anaphylaxis ; however, lymphocyte stimulation test was negative for both drugs. As the patient was scheduled for another surgery under general anesthesia, she came to our department for further investigation. Basophil activation test (BAT) and prick test showed positive ndings only for sugammadex ; hence, we diagnosed postoperative hypotension and generalized erythema caused by an immediate anaphylactic shock to sugammadex. As the patient did not show symptoms following initial administration of sugammadex, a possible mechanism for the delayed anaphylactic symptoms was due to sensitization because the basic component of the drug, γ-cyclodextrin, is contained in many dietary supplements and cosmetics. Skin Research, 22 : 1-6, 2023

A 61-year-old woman presented with 5 weeks of fever and redness, swelling, and heat of the left thigh, which had not improved with intravenous infusion of antibiotic agent. Clinical ndings showed erythematous subcutaneous nodules and heat of left lateral and posterior thigh. Subcutaneous nodules were also observed in the right posterior thigh, right temple, and left cubital region. Histopathologically, cellular inltrate involving lobules within the subcutaneous tissue was observed. Immunohistochemistry revealed that inltrated cells were positive for CD3, CD8, TIA1, and granzyme B, and negative for CD4, CD20, and CD56. Based on these ndings, she was diagnosed with subcutaneous panniculitis-like T-cell lymphoma. Erythematous subcutaneous nodules of both thighs were resolved with administration of prednisolone (1 month) and cyclosporine (10 months). She had no recurrence for 2 years since receiving treatment. Subcutaneous panniculitis-like T-cell lymphoma is a rare lymphoma, which has poor prognosis when a hemophagocytic syndrome/hemophagocytic lymphohistiocytosis is present. Thus, it is important to perform skin biopsy for early diagnosis of the disease when a patient presents intractable skin redness, swelling, and nodules. Skin Research, 22 : 7-12, 2023

An 85-year-old man presented with severe scaly erythema on his left cheek. The symptoms gradually worsened despite topical steroid treatment and spread to the trunk and buttock, leaving vesicles and erosions. There were no mucosal lesions. Direct immunouorescence staining showed deposition of IgG on the intercellular surface of keratinocytes, and high titres of IgG antibodies to desmoglein 1 were obtained, but not to desmoglein 3. We made a diagnosis of pemphigus foliaceus and started oral predonisolone treatment. The symptoms improved ; however,the pustular skin lesions recurred when the dose of predonisolone was reduced. Histopathological examination showed formation of subcorneal pustules containing many neutrophils with a few acantholytic keratinocytes mimicking Kogoj’s spongiform pustules. Based on the increased titres of IgG antibodies to desmoglein 1, we prescribed a higher dose of predonisolone, and the symptoms subsided immediately. There are some similar case reports of pemphigus foliaceus with prominent neutrophic pustular skin lesions ; however, the causative mechanism of the accumulation of neutrophils and the pustule formation remains to be elucidated. The present case reconrms the importance of direct immunouorescence staining and taking titres of IgG antibodies to desmoglein 1 for following up patients with pemphigus foliaceus. Skin Research, 22 : 13-18, 2023

A 30-year-old female had been suffering from multiple pruritic nodules on her extremities since elementary school. Her local doctor prescribed topical steroids for external use as needed. An ulcer that was refractory to oral antibiotics and isodine sugar paste ointment appeared on the right leg 7 months before her rst visit to our department. At the initial examination, a necrotic and cavelike ulcer, 3 cm×3 cm in size, satellited with old pruritic nodules was observed. Skin biopsy from the border of the ulcer revealed a ower-basket-like proliferation of spindle-shaped cells in the dermis which were strongly positive for CD34 ; therefore, the initial diagnosis was dermatobrosarcoma protuberans. A second histopathological examination after wide resection of the tumor revealed epithelial-like oval cells in addition to spindle-shaped cells deeply proliferated from the dermis to muscular fascia with an island-like pattern structure. Based on these immunohistochemical and histopathological results, the tumor was diagnosed as epithelioid sarcoma. We performed lymph node dissection for inguinal lymph node metastasis. Epithelioid sarcoma is a rare soft tissue malignancy that is prone to local recurrence and distant metastasis. Our ndings suggest that although epithelioid sarcoma is rare, it should be considered a differential diagnosis for intractable skin ulcer. Skin Research, 22 : 19-23, 2023

A 75-year-old male noticed redness and swelling of the right hallux during chemotherapy for lung cancer. Antibiotics were administered by his primary doctor. His cutaneous symptoms initially improved ; however, they relapsed shortly afterwards, and he was referred to our department. At the rst visit, he had redness, swelling, and heat sensation in the right hallux. Whitlow was suspected and he was treated with intravenous antibiotics. Three weeks later, a bloody nodule was newly found on the right hallux. CT of the right foot showed osteolytic changes in the distal phalanx of the right thumb and a 38 mm large solid mass contiguous with the bone. Histopathology showed proliferation of tumor cells with nuclear atypia and mitotic gures. Immunohistochemically, the tumor cells were positive for both p40 and CK5/6. Based on these ndings, we made a diagnosis of skin metastasis from lung cancer to the right hallux. Although cutaneous metastasis of malignant tumors of the internal organs to the digits is very rare, lung cancer and esophageal cancer are frequently reported as primary lesions of metastasis. Our ndings suggest that it is necessary to differentiate metastatic skin tumor in patients presenting with possible paronychia or whitlow-like lesion. Skin Research, 22 : 24-29, 2023

Abstract : A 53-year-old man with a history of skin blistering on his palms, soles, elbows, and knees since childhood presented to our dermatology department. His ngernails and toenails were lost when he was an elementary school student. Physical examination revealed eyelid ectropion,scarring of hands, digital webbing and fusion, nger and toenail loss, and blood blisters and excoriation on his soles. Histological study of an induced blister revealed blistering within epidermis and dermis. Immunouorescent staining of type IV collagen demonstrated no sign of reduplication of basement membrane. No pathogenic variant was found in COL7A1 or FERMT1 by Sanger sequencing performed at the age of 52. Nine years after the initial visit, a homozygous COL17A1 p. R1303Q was detected by whole exome sequencing, and a diagnosis of late onset junctional epidermolysis bullosa was made. Skin Research, 22 : 30-35, 2023

A 44-year-old woman had repeated duodenal ulcer for 3 years since her rst visit. Investigations performed 3 months prior to presentation revealed pyloric stenosis secondary to scarring, which resulted in prolonged nausea and loss of appetite. She developed erythema on both ngers and did not show improvement despite treatment at a previous hospital. Subsequently, erythema and erosion extended to the dorsum and palms of both hands with the appearance of erythema and pustules between the eyebrows and both nose wings. Blood test results showed a low level of nicotinic acid, so we initiated nicotinamide therapy for suspected pellagra. Signicant improvement in the eruption following 2-week nicotinamide administration was observed. In the present case,intractable erythema was found in the stimulated area, even in the unexposed area. Herein, we report the mechanism of the appearance of eruption in the stimulated area in pellagra, including a review of the literature. Skin Research, 22 : 36-41, 2023

Case 1 was a 35-year-old woman and Case 2 was a 25-year-old woman. Both patients had livedo reticularis and painful ulcers on the lower legs and dorsum of the foot. The patients were diagnosed as having livedo vasculopathy based on clinical ndings and histopathological examinations. Both patients were treated with anticoagulants, including edoxaban, antiplatelet agents, and vasodilators,and their symptoms improved. However, both of their conditions relapsed ; therefore, we replaced edoxaban with dabigatran, which resulted in a signicant improvement. Recent studies on the effectiveness of direct oral anticoagulants (DOACs) for livedo vasculopathy have yielded mixed results. We report two cases where the symptoms improved after switching from edoxaban to dabigatran. Our ndings suggest that changing DOAC may be effective in the treatment of refractory livedo vasculopathy. Future studies with more cases are necessary. Skin Research, 22 : 42-48, 2023

A 42-year-old woman presented to our hospital with a right putaminal hemorrhage that developed 4 months previously and asymptomatic erythematous papules that appeared on her face 3 months previously. She had a history of polycystic liver disease and habitual abortion. Histopathological ndings of the biopsy tissue obtained from erythematous papules on her left mandible revealed naked granulomas with Langhans giant cells in the dermis. She was diagnosed with cutaneous sarcoidosis based on normal blood angiotensin-converting enzyme, calcium levels, and the absence of lesions in other organs as seen in hilar lymphadenopathy. Furthermore, she was diagnosed with antiphospholipid antibody syndrome by the Department of Rheumatology at our hospital based on her history of habitual abortion and the presence of positive lupus anticoagulants. Complications of polycystic liver disease, antiphospholipid antibody syndrome, and cutaneous sarcoidosis are extremely rare and to the best of our knowledge there are no previous reports. Cutaneous sarcoidosis may subsequently occur in different organs than the initial diagnosis. In a previous case report, a patient initially diagnosed with pulmonary sarcoidosis and polycystic liver disease ultimately developed hepatic sarcoidosis, resulting in a more severe prognosis. Careful systemic tests are essential to ensure early detection of granulomatous lesions that may develop in other organs and curtail the risk of recurrence of thrombosis. Skin Research, 22 : 49-55, 2023

An 86-year-old woman was presented to our institution with solitary ulcerated skin lesion on the left lower leg. She had a history of cervical cancer at the age of 49 that was treated with surgery and postoperative radiation therapy, and had suffered from subsequent lymphedema of the left leg and recurrent cellulitis. Skin biopsy was performed and a histopathological diagnosis of primary cutaneous diffuse B-cell lymphoma, leg-type, was made. Previous studies reported that skin infections, including cellulitis, are more likely to develop in chronically lymphedematous limbs. It has been reported that the lymphedematous region is immunologically vulnerable and predisposed to malignancies and infectious diseases. Angiosarcoma is the most common cutaneous malignancy associated with chronic lymphedema, which is known as Stewart-Treves syndrome. To date, 21 cases of primary cutaneous lymphoma arising in lymphedematous limbs have been reported,including the present case. These cases suggest a potential correlation between chronic lymphedema and the development of malignant lymphoma. Diverse malignancy, including angiosarcoma, may occur in lymphedematous limbs. Skin Research, 22 : 56-63, 2023