I came across the original publication of the Blaschko line, which is important in dermatology. Although the introduction of this book is useful for us Japanese dermatologists, it is written entirely in German, which makes it difficult for the general public to read and understand. Therefore, I translated it into English and Japanese in two stages. Even so, it is still difficult to read and understand the entire text, so an abridged translation has been prepared and presented here. The purpose of this article is not to be read as a mere nostalgic hobby, but to provide a better understanding of the Blaschko line, which we dermatologists use on a daily basis. I also advocate pointing out its problems and improving it. Skin Research, 20 : 273-292, 2021

A 51-year-old man was treated for atopic dermatitis (AD) for decades. He visited the ophthalmologist for poor eyesight and angioid streaks were noted. He was referred to our dermatology department to evaluate pseudoxanthoma elasticum (PXE). At the first visit, the skin of his neck and axilla was rough, resembling typical skin lesions of AD rather than PXE. Skin biopsy from his neck revealed degenerated elastic fibers and calcium deposition in the dermis without changes such as inflammatory changes of AD. We diagnosed him with PXE. Although typical skin lesions of PXE (yellow papules) were not found on the rough skin of his neck, several yellow-brown spots were found by dermoscopy. The findings on dermoscopy were histologically compatible with PXE without AD changes. Furthermore, the patient was allergic to house dust and mites, and had a history of repeated itchy eczema. We suspected PXE complicated by AD. There is only one case report about PXE associated with AD, but the association between skin types of PXE and AD was not described in detail, including dermoscopy findings. Although this is only a case report, we suspected the rough skin lesion on his neck to be an atypical PXE skin finding. We hypothesize that yellow-brown spots on dermoscopy will become yellow papules macroscopically, which are typical skin lesions of PXE. PXE is often misdiagnosed because it is unfamiliar, subjective symptoms of the skin are relatively unclear for patients, and it is difficult to distinguish atypical skin findings of PXE from those of other inflammatory skin diseases, as in our case. It is highly recommended that we recognize different skin manifestations and complications of PXE to make a diagnosis and provide appropriate treatment. Skin Research, 20 : 293-298, 2021

A 62-year-old female was referred to our hospital for examination of a skin lesion on her left epigastric region, which developed 6 years before her first visit to our hospital. Orange-yellow or red papules aggregated and fused to form a slightly hard, shiny plaque on her left epigastric region. Furthermore, soft, partly wrinkled, and skin-colored or pink nodules developed on her left vulva 2 years before her visit. Histopathological examination of both skin lesions revealed amyloid deposition derived from immunoglobulin light chain kappa. Around the same time, she visited the department of urology for pain in her genital area and was diagnosed with bladder amyloidosis. Amyloid deposition was confirmed in her skin and bladder, but she was diagnosed with localized amyloidosis based on the amyloid-deposited organs, laboratory findings, and clinical course. The skin lesions on her epigastric region and vulva exhibited different clinical features, but both lesions were diagnosed as localized cutaneous nodular amyloidosis due to the histopathological findings. According to previous reports, localized cutaneous nodular amyloidosis exhibits many clinical features, and it may be overlooked in daily medical practice. Skin Research, 20 : 299-308, 2021

A 72-year-old male patient exhibited ptosis in both eyelids. Ptosis developed in the left eye 57 days after the administration of 240 mg of nivolumab for Stage IV (T4bN1bM1c (0)) malignant melanoma on his right heel. Ptosis developed in both eyes from the 71st day. The patient had difficulty opening both eyes, but no abnormality was observed in the movement of the eyeballs. Blood fractionation revealed an increase in CK, but anti-acetylcholine antibodies and anti-musclespecific kinase antibodies were absent. Based on the clinical course and test results, the administration of nivolumab was considered to have caused myasthenia gravis in the muscles around the eyes. Therefore, 30 mg per day of prednisolone was administered on the 71st day. At present,the dose of prednisolone has been reduced to 5 mg per day with no apparent worsening of the condition. In this case, rapid improvement was achieved without an increase in severity because treatment with steroids was started at the outset. Furthermore, combination with steroid treatment made it possible to continue the administration of nivolumab. As reports of ptosis following nivolumab administration are rare, this is an important case. Skin Research, 20 : 309-313, 2021

A 65-year-old man visited a doctor 10years ago because an erythematous nodule appeared in a normal skin-colored plaque on his head that had been present since birth. Extensive resection and full-thickness skin grafting were performed at that time. The histopathological examination revealed that it was an apocrine adenocarcinoma that arose from the sebaceous nevus. One year prior to his first visit to our hospital, he noticed a subcutaneous nodule at the edge of the skin graft. The patient visited his previous doctor who noticed a swollen right clavicle lymph node. A diagnosis of recurrent apocrine adenocarcinoma with lymph node metastasis was made and he was referred to our department for further treatment. Extensive resection and right cervical lymph node dissection were performed. The histopathological examination revealed extranodal invasion of the cervical lymph nodes. Therefore, postoperative radiation and chemotherapy were administered. To date,after more than 3 years, no recurrence or metastasis has been observed. Several reports stated that apocrine adenocarcinomas can recur or metastasize after an extended period, demonstrating that long-term follow-up is required. However, an effective treatment for advanced-stage apocrine adenocarcinoma has not been established yet. We hope that more reports will be accumulated in the future. Skin Research, 20 : 314-319, 2021

A 77-year-old woman noted subcutaneous masses in the left and right iliac region 3 months prior to her first visit. She came to our hospital because they increased in size. At the time of the first visit, a fist-sized elastic hard subcutaneous mass was found in the left iliac region and a 4×2cm-sized subcutaneous mass with a reddish elevated surface was found in the right iliac region. Each subcutaneous mass was biopsied. Histopathological examination demonstrated widespread calcification from the dermis to the subcutaneous tissue in both lesions. Infiltration of inflammatory cells around the calcification was observed, but no foreign body giant cells or pseudocyst-like changes were observed. Blood tests, including Ca, P, and PTH levels, were normal, and no abnormalities in collagen-related autoantibodies or tumor markers were found. Both MRI and CT of the pelvic region revealed soft shadows, mainly calcification, in the subcutaneous fat of the lateral gluteal muscles on both sides. Based on these findings, a diagnosis of idiopathic cutaneous calcinosis (tumoral calcinosis) was made. As there was no increase in the size of the lesions after the diagnosis, total excision was not performed and the patient was followed up every 3 months. It has now been one year and nine months since the diagnosis of the disease, but there has been no increase in size in either mass. There have been 16 reported cases of tumoral calcinosis in Japan since 1983. Of these, only three cases of multiple lesions were found, including our case. In cases of multiple subcutaneous masses in the iliac region, cutaneous calcinosis should be included in the differential diagnosis, and blood tests and imaging studies should be actively performed. Skin Research, 20 : 320-324, 2021

A 78-year-oldman developedfever andgeneral malaise on day 0, which resolvedspontaneously. On day 19, general malaise reappearedwith systemic erythema intermingledwith purpura. The presence of systemic deep lymphadenopathy and splenomegaly prompted us to consider malignant lymphoma, which was later excluded. Systemic prednisolone was started at 20 mg/day on day 21 and was increased to 60 mg/day on day 25. The rash disappeared on day 34. After day 42, anemia progressedandredbloodcell transfusion was performed. A positive Coombs test andmarked erythroidhypoplasia of the bone marrow ledto a diagnosis of autoimmune hemolytic anemia andpure cell aplasia. As serum human parvovirus B19 IgM, which hadbeen negative on day 25, became positive on day 46, the patient was diagnosed with human parvovirus B19 infection. The patient had no history of immunodeficiency or hemolytic anemia. Human parvovirus B19 infection shouldbe considered in patients presenting with purpura of unclear origin. Skin Research, 20 : 325-331, 2021

A 77-year-old woman, who had been treated with pembrolizumab for lung adenocarcinoma,developed erythematous papules with mild itching on her limbs during the 24th course of immunotherapy. Her skin lesions gradually expanded and she was referred to us a month after the onset. Due to the progression of the primary and metastatic lesions of lung cancer, pembrolizumab was discontinued. At the first visit, hyperkeratotic erythematous lesions, some with central crusting, were observed mainly on her distal extremities. Histopathological examination demonstrated epidermal necrosis at the center of the lesion. Many dyskeratotic cells and mononuclear cell infiltration, which consists chiefly of CD8positive lymphocytes, were observed in the epidermis, with vacuolar alteration of the basal layer. Although we considered the cutaneous manifestations to be a lichenoid eruption, topical steroid therapy failed. Our reconsideration of clinical and histopathological findings of extensive necrosis together with numerous dyskeratotic cells in the epidermis led to a diagnosis of close pathophysiological resemblance to pityriasis lichenoides et varioliformis acuta (PLEVA). Subsequent oral administration of macrolide antibiotics based on this diagnosis improved the cutaneous lesions. There have been no reports of lichen planus or PLEVA-like eruption caused by lung cancer. In this case, neither infectious disease nor a drug evoking drug allergy was found. This suggested that pembrolizumab caused the rash. Therefore, this case was considered an immune-related adverse event of anti-PD-1 therapy. As PD 1 blockade can often cause lichenoid eruption, which exhibits differing degrees of clinical and histopathological changes, we diagnosed the patient with lichenoid eruption. Skin Research, 20 :332-337, 2021

An 83-year-old man developed ulceration on his right forearm after being bitten by an insect. He received topical steroids for three months without improvement and was referred to our department. On examination, an ulcer the size of a thumb tip surrounded by erythema was observed on the lateral side of the right forearm. The ulcer margins exhibited a moth-eaten appearance. Histopathological examination revealed the dermal infiltration of inflammatory cells, mainly consisting of lymphocytes and plasma cells containing basophilic yeast-like fungi. Periodic acid-Schiff (PAS) staining and Grocott staining revealed many fungal elements in the dermis. Fungal culture yielded velvet-like colonies having off-white wrinkled walls with brownish pigments. The slide culture resulted in elongated hyphae having partitioned walls, with circular conidia on their side walls and tips. A diagnosis of fixed cutaneous sporotrichosis was made. Oral itraconazole (100 mg/day) and local hyperthermia were initiated. The ulcer gradually shrank and healed in approximately two months. In our case, a large number of fungal cells were found in the skin biopsy specimen, which may have resulted from the long-term use of topical steroids. Skin Research, 20 : 338-342, 2021

A 57-year-old man was referred to our department with scaly erythema over the face, trunk, and extremities. He had a history of metastatic thymoma and myasthenia gravis (MG). He underwent thymectomy 11 years prior and chemotherapy 9 years prior. He had been admitted to the department of neurology due to muscle weakness, fatigability, and dysgeusia. He presented with extensive erythema and scaling over his entire body, and was in a state of erythroderma. In addition, he had leg edema and white patches on the tongue. Skin biopsy from the thigh demonstrated hyperkeratosis with parakeratosis, epidermal liquefaction and spongiosis, apoptosis of keratotic cells in the epidermis, and lymphocytic infiltration into the epidermis and dermis. Based on the graft-versus-host disease (GVHD)-like skin symptoms, accompanied by thymoma and MG, we diagnosed the condition as thymoma-associated multi-organ autoimmunity (TAMA) complicated by MG. Topical corticosteroid treatment moderately improved the erythema. A 3 day course of intravenous methylprednisolone improved the dysgeusia. However, pneumonia occurred frequently due to Pseudomonas aeruginosa infections and we detected low immunoglobulin G (IgG) levels. He was promptly treated with antibiotics and supplemental intravenous immunoglobulin (5 g/day, three days). His general condition recovered temporarily, but he developed disseminated Mycobacterium abscessus infection and passed away 10 months after the first visit. TAMA was reported to affect the skin, liver, and colon, and it is clinicopathologically similar to GVHD. GVHDlike erythroderma is a cutaneous feature of TAMA. MG is a frequent autoimmune complication of TAMA, and TAMA can be accompanied by reduced serum IgG levels and Good syndrome. Patients with TAMA that exhibit GVHD-like erythroderma generally have an unfavorable clinical course related to severe infections. Skin Research, 20 : 343-348, 2021

A 53-year-old woman. A subcutaneous mass was removed from the left clavicle region when she was 8 years old. A mass developed in the left subcutaneous chest at around 43 years of age. CT revealed mass lesions in the left proximal clavicle and mediastinum, and the patient was referred to our hospital. Left subcutaneous hemangioma of the clavicle and mediastinal hemangioma were considered, and total resection was performed. Pathological examination revealed the subcutaneous mass to be cavernous hemangioma and the mediastinal lesion to be mediastinal hemangioma. Subcutaneous cavernous hemangioma associated with mediastinal hemangioma is rare. As there are reports of hemangiomas in other organs and associated symptoms, it is necessary to search for the presence of visceral hemangioma. Skin Research, 20 : 349-353, 2021

Moisturizers exist in numerous dosage forms, and the usefulness and effectiveness of the moisturizer vary depending on its dosage form. Continued use of moisturizers is important in the long-term treatment of dry skin disease and for achieving therapeutic efficacy, thus moisturizers that match the patient's skin symptoms and preferences are needed. This study compared the usefulness of moisturizers and differences in patient satisfaction in terms of dosage forms and combinations. Sixty-six patients with dry skin symptoms were divided into three groups : lotion alone, cream alone, and lotion combined with cream ; and moisturizer was applied to the dry area twice daily for 8 weeks. The following were measured at the beginning and end of the study :Stratum corneum water content at the application (cheek, inner forearm) and non-application (upper back) sites, and degree of multilayer exfoliation of the stratum corneum. Participants were also asked to fill out a patient satisfaction survey. After 8 weeks, the following results were observed :At the application sites, the stratum corneum water content significantly increased, whereas the degree of multilayer exfoliation significantly decreased. In addition, the stratum corneum water content significantly increased in all groups, but the degree of multilayer exfoliation significantly decreased in the cream alone group. Furthermore, according to the survey, the desire for continued moisturizer use was highest in the combined (lotion ＋ cream) group. Continuous use of moisturizers, along with treatment for primary diseases, is important in the treatment of longstanding dry skin diseases, and the selection of moisturizers according to skin dryness and patient preferences may lead to improved adherence. Skin Research, 20 : 354-360, 2021