Hyperhidrosis is a condition that negatively affects a patient’s quality of lifeand work productivity due to sweating in excess of the amount needed to regulate body temperature. The global average temperature has been increasing in recent years. As sweating is affected by climate change, it has become increasingly meaningful to analyze the disease from a meteorological perspective. We conducted a preliminary investigation into the correlation between medical data on hyperhidrosis and meteorological data. (Method) We extracted medical information from claim data provided by the social health insurance program operated by JMDC Inc., as well as meteorological data from the Japan Weather Association. We investigated the distribution of the number of patients by time and region. We included a total of 1,037,269 patients with“excessive sweating”or other symptoms reported on claims between January 2015 and September 2022. The association between the number of patients and meteorological data was analyzed by univariate analysis. Furthermore, we calculated the timing of high prevalence of hyperhidrosis based on minimum temperature and perceived temperature for each year. (Result) Throughout the observation period, a cyclic pattern was observed, peaking in the summer months. Univariate analysis revealed that the meteorological data variables most correlated with the number of patients with hyperhidrosis in terms of coefcient of determination were minimum temperature and perceived temperature. The timing of high prevalence of hyperhidrosis varied by region. Skin Research, 23 : 251-261, 2024

A 91-year-old man undergoing dialysis, with no history of immunosuppressive drug use, noticed a subcutaneous induration at the site of a u vaccination he had received several months earlier on his right upper arm. The induration got bigger and gradually ulcerated. Histopathological analysis revealed proliferation of CD20- and EBER-positive atypical lymphocytes ; however, no abnormalities were detected in bone marrow examinations or PET-CT. We diagnosed him with EBV-positive mucocutaneous ulcer (EBVMCU), which started to regress spontaneously with only observation after two months from the rst visit. EBVMCU is an ulcerative lesion conned to the oropharynx,gastrointestinal tract, and skin. It is classied as a type of EBV-associated B-cell lymphoproliferative disorder. It is known to develop under immunosuppression, but old age may also be a trigger. EBVMCU has a good prognosis because of spontaneous regression following cessation of immunosuppressive treatments or observation. It is difcult to differentiate from diffuse large B-cell lymphoma and other lymphomas based on histopathology alone. Diagnosis should be made carefully based on the patient’s medical history and general condition, the presence of lymphadenopathy, and the results of bone marrow examination. Skin Research, 23 : 262-268, 2024

A 33-year-old previously healthy male presented with an abnormality on his scalp, which he had rst noticed three weeks earlier. The scalp was thickened, raised, and symmetrical, with wrinkles resembling the convexity of the cerebral cortex. We diagnosed the condition as cutis verticis gyrata (CVG) and proceeded with differential diagnosis. We found that the patient did not have ophthalmological or neuropsychiatric diseases, cutaneous tumors, inammation, visceral malignancies, or endocrine abnormalities. Based on the history and examination results,pachydermoperiostosis (PDP) was suspected. Prostaglandin E2 metabolism was normal, and genetic testing showed mutations in only one allele of the SLCO2A1 gene. As there were no other ndings, PDP was excluded. The possibility of other secondary CVG was also ruled out based on the patient’s medical history and test results. As the patient had no other comorbidities suggestive of primary nonessential CVG, he was diagnosed with primary essential CVG. CVG is a rare disorder that requires differentiation from various underlying diseases. Skin Research, 23 : 269-274, 2024

A 69-year-old woman presented with multiple small petechiae on both lower legs. Proteinuria and occult blood were detected in her urine. After 2 days, she was hospitalized because of new bloody vesicles/bullae and skin ulcerations. Based on a skin biopsy result, the patient was diagnosed with IgA vasculitis. Methylprednisolone pulse therapy was initiated, followed by oral prednisolone (PSL) 20 mg/day. As severe gastrointestinal symptoms developed, the oral PSL dose was increased to intravenous 40 mg/day, and a coagulation factor XIII concentrate was administered. The gastrointestinal symptoms improved ; however, the urinalysis ndings worsened. Renal biopsy revealed pathological ndings compatible with IgA nephropathy. Therefore, the oral PSL dose was increased to 60 mg/day, and cyclophosphamide (CPA) (500 mg intravenously) was administered. The recalcitrant skin eruptions improved after adding diaphenylsulfone and CPA. On day 57, the patient was discharged from the hospital with residual urinalysis ndings. After discharge,refractory skin ulcers developed on the patient’s lower legs. Colchicine (1 mg/day) was initiated,and the leg ulcers gradually epithelized. Adult patients with IgA vasculitis are prone to multipleorgan complications. Although the severity of gastrointestinal symptoms is important for acute prognosis, the severity of nephritis is relevant for long-term prognosis. No standard regimen exists regarding the choice and dose of immunosuppressive agents for cases refractory to high-dose glucocorticoids ; thus, further studies are necessary. Assessment of blood samples, including factor XIII, fecal occult blood, and abdominal computed tomography, as well as collaboration between nephrologists and gastroenterologists are essential for early intervention. Skin Research, 23 : 275-282, 2024

Infantile acropustulosis is characterized by the periodic appearance of aseptic pustules on the palms and soles of infants. Herein, we describe an 11-month-old girl who presented with multiple pustules on the palmoplantar area and scattered erythema on the trunk and extremities at the time of initial examination. During the course of the disease, scabies mite eggs were found on the trunk, leading to a diagnosis of scabies. She was treated with topical phenothrin lotion 5%. Scabies mites and eggs were also found on her grandmother. After treatment for scabies, the patient continued to have a low-grade fever ; papular erythema on the face, trunk, and extremities ; and aseptic pustules on the palmoplantar area, which recurred and faded periodically. We continued treatment with 1 : 1 : 1 mixture of topical gentamicin sulfate, topical betamethasone valerate, and zinc oxide ointment, as well as oral levocetirizine hydrochloride syrup. Five months after the initial visit, the rash became more localized on the palms and soles, and the interval between the are-ups lengthened. Because the aseptic pustules persisted after scabies treatment, a diagnosis of infantile acropustulosis was made. The cause of infantile acropustulosis is unknown ; however, when it develops after scabies treatment, hypersensitivity to scabies is a possible contributing factor. As infantile acropustulosis is self-limited, unnecessary application of phenothrin should be avoided. Skin Research, 23 : 283-288, 2024

A 71-year-old female presented with a poorly marginated, erosive, at-elevated lesiononthe left temple. Cryotherapy was initially performed ; however, the lesionpersisted. Skinbiopsy demonstrated tumor nests radiating from the walls of several follicular infundibula into the dermis,accompanied by a keratinous mass in the center. Tumor nests were composed of atypical squamoid cells with distinct nucleoli and variously sized nuclei. There were no atypical cells in the surface epidermis. A diagnosis of infundibular SCC was made. Despite three complete excisions, the margins were positive in each of the resected specimens. We administered systemic irinotecan ;however, in-transit metastasis occurred on the left cheek. We performed local electron beam irradiation to the left temple and left cheek. Following irradiation, numerous nodules developed successively inboth areas, which were treated externally with uorouracil. The patient declined the systemic administration of nivolumab. She died 12 months after surgery. Previous studies of infundibular SCC reported an indolent course ; however, it sometimes follows a progressive course,as in the present case. Determining the resection margin of infundibular SCC is challenging for dermatologists due to the tumor’s proliferation pattern, which radiates from the follicular infundibula within the dermis. Further case accumulation is needed for the future improvement of prognosis. Skin Research, 23 : 289-294, 2024

A 71-year-old man was diagnosed with psoriasis vulgaris around 40 years of age, and psoriatic arthritis around 66 years of age. His previous doctor prescribed apremilast ; however, the patient self-discontinued it after 2weeks. At the age of 70, he was referred to our hospital due to worsening psoriasis despite treatment with topical application and phototherapy. After restarting apremilast,the patient experienced an improvement in psoriasis. However, 3 months after resuming oral medication, blisters and erythema emerged on the trunk and extremities, accompanied by ulcers in the mouth and genital regions. A skin biopsy was performed on a blister located on the right elbow joint. Histopathological examination revealed subepidermal bullae, with inltrating cells primarily composed of neutrophils. Direct immunouorescence revealed deposition of immunoglobulin G (IgG) and C3 in the basement membrane zone. Immunoblotting revealed IgG reactivity to the recombinant protein for the C-terminal fragment of human p200. The patient was diagnosed with anti-p200 pemphigoid. We discontinued apremilast and initiated oral administration of 50 mg/day prednisolone and diaphenylsulfone (DDS), which resulted in improvement of the blisters and erythema. Despite gradual tapering of prednisolone, new blisters persisted. This made it challenging to reduce the dosage of prednisolone to less than 15 mg/day. Furthermore, new blisters continued to appear even after the addition of minocycline and mizoribine. Increasing the dose of DDS led to an improvement in the formation of new blisters. Subsequently, prednisolone was reduced to 10 mg/day ; however, new blisters reappeared. Mizoribine was substituted with cyclosporine A, leading to no exacerbation. Following the discontinuation of prednisolone, we are currently tapering the dosage of cyclosporine A. Skin Research, 23 : 295-300, 2024

A seven-year-old boy visited the dermatology department of our hospital for facial freckle-like and pigmented macules on the dorsum of the back of his hands and feet that rst appeared when he was around six years old. Thereafter, both pigmented and depigmented macules occurred frequently and spread to his four limbs. The patient’s family history conrmed the absence of the same symptoms in his grandparents, parents, and younger sisters. His clinical symptoms at the rst visit included facial freckling and a dense mixture of punctate pigmented and depigmented macules on the periphery of his four limbs. Histopathological ndings revealed melanin accumulation in the basal layer of the pigmented areas, whereas the number of melanocytes and melanin deposition were signicantly decreased in the depigmented areas. The patient and his family underwent genetic testing, which identied the c.1078C＞T (p.Arg360Ter) mutation in the ADAR gene, exclusively in the patient. He was diagnosed with a sporadic case of dyschromatosis symmetrica hereditaria. Following the diagnosis, the skin rash exacerbated the pigmented and depigmented macules on the dorsum of his hands due to sun exposure ; therefore, we instructed the patient to use sunscreen to block sunlight and are conducting follow-up observation. Dyschromatosis symmetrica hereditaria shows autosomal dominant inheritance, but sporadic cases have been reported. Genetic analysis is useful for distinguishing it from other hereditary dyschromatoses. Since this case involves a child, it is essential to monitor the patient’s growth and clinical symptoms in the future, follow up with him and his family, and provide long-term support, including genetic counseling sessions. Skin Research, 23 : 301-306, 2024

A 13-year-old Japanese female with cerebral palsy, microcephaly, and epilepsy was admitted to a previous hospital 11 years prior. Twelve days earlier, an erythema measuring 5×17 cm was noticed on her abdomen. Although the erythema disappeared 2 days after the application of topical corticosteroids, new blisters developed around the site of the erythema. The blisters spread to both upper and lower extremities and did not improve ; therefore, she was transferred to our hospital for further examination and treatment. When she was transferred to our hospital, the large erythema and blisters on her trunk had already progressed to hyperpigmentation and pale erythema. Erosions were seen on the proximal extremities and tense blisters ranging from several millimeters to several centimeters in size were observed on the distal areas including palms and soles. Histopathological examination revealed neutrophilic inltration within the blisters. Direct immunouorescence assay showed granular deposition of IgA and IgM on the basement membrane zone. The blisters resolved with the application of topical corticosteroid. IgA deposition on the basement membrane zone led us to consider chronic bullous dermatosis of childhood (CBDC) and dermatitis herpetiformis Duhring as differential diagnoses. Granular deposition of IgA is rarely observed in CBDC ; however, a diagnosis of CBDC was comprehensively made because of the distribution, characteristics, and course of the rash. In the present case, blisters were predominantly distributed on the extremities. Previous reports have suggested decreased cutaneous nerve blood ow and altered autonomic nervous system function on the skin of the paralyzed area. When bullous lesions occur in patients with cerebral palsy, it is important to consider that they may predominantly affect the extremities or persist there longer than in other body areas, as demonstrated in the present case. Skin Research, 23 : 307-312, 2024

Idiopathic anaphylaxis (IA) refers to a severe, life-threatening allergic reaction where no denable etiology or exogenous allergen triggers are found. IA is diagnosed when the trigger cannot be identied despite a detailed medical history at onset, skin tests, serum-specic IgE levels, and a stepby-step provocation test. Differential disorders include food allergy, mast cell disease, clonal mast cell abnormalities, panic disorder, and hereditary or acquired angioedema. We retrospectively analyzed the clinical characters of 11 patients with IA who visited our hospital between September 2009 and June 2021. Mean age was 42.7 years old, and the sex ratio was three males to eight females. Median total IgE serum levels were 99.1 IU/ml. Seven patients had a history of atopic diseases (three pollen allergy, two asthma, one atopic dermatitis, one allergic rhinitis). The most common symptoms include abdominal issues, such as vomiting and diarrhea, followed by angioedema,urticaria, and throat tightness. Regarding treatment, ten patients were treated with H1 receptor antagonist, three with H2 receptor antagonist, one with tranexamic acid, six with adrenaline autoinjection, and one with prednisolone. The number of attacks decreased in all 11 patients. The mean age, female predominance, and prevalence of atopic diathesis in the 11 IA cases were similar to previous studies. Although it is difcult to determine the therapeutic effect of IA, which can resolve spontaneously, our ndings suggest that the regular use of H1 receptor antagonist is efcacious in reducing the frequency of anaphylaxis. Skin Research, 23 : 313-317, 2024

A 77-year-old woman was consulted to our hospital for pruritic erythema with scales on the right scalp. She had been treated with topical steroidal ointment for 2 months at a previous clinic ; however, no improvement of symptoms was observed. At the rst visit, she had erythema with thick scales and yellow crusts on the right postauricular region to the right side of the occipital region. We could not nd the fungal elements microscopically in the specimen and the pathological examination (PAS) of skin biopsy from the lesions ; therefore, we continued treatment with the topical steroid that she was administered at her previous clinic. The erythema improved ; however,an area of hair loss appeared, which enlarged one year later. When she visited our hospital again,the lesion was diagnosed as Kerion celsi by the fungus elements microscopically in a specimen of the lesion and by the PAS of the lesions. The fungus was identied as Trichophyton rubrum. She was treated with terbinane hydrochloride 125mg/day orally and 1% topical terbinane hydrochloride for 5months and achieved cure. Due to treatment with topical ketoconazole for seborrheic dermatitis,we encountered unexpected difculties in diagnosing Kerion celsi. When treatment for eczema capitis is ineffective, it is essential to repeat fungal examinations, including fungal culture, without being overly focused on the initial diagnosis. Skin Research, 23: 318-323, 2024

A 15-year-old male with no previous medical history had a solitary red skin tumor on his back,which had been growing slowly over several years. Physical examination revealed a 12×15×5 mm-sized, dome-shaped rm nodule on the right upper back. Histopathological examination of the excisional specimen revealed a dermal neoplasm with a multinodular distribution, consisting of a fascicular proliferation of epithelioid and short-spindle cells, separated by brous stroma. Mucinous stroma was seen focally. On immunohistochemistry, the neoplastic cells were positive for NKI/C3 and negative for S-100. The distinct histopathological ndings as well as immunohistochemistry led to the nal diagnosis of cellular neurothekeoma. Although cellular neurothekeoma is relatively rare and difculttodene based on clinical and dermoscopic ndings, it is important to make a correct diagnosis by performing immunohistochemistry based on the characteristic pathological ndings. Skin Research, 23 : 324-327, 2024