A 36-year-old man developed edema on his upper eyelids approximately 6 years ago, and the asymptomatic erythematous edema gradually spread to his nose and cheeks. Histopathological investigation of the skin of his left cheek revealed lymphatic vessel expansion and infiltration of inflammatory cells―mainly lymphocytes―around blood vessels and hair follicles, with no granulomas. Alcian blue staining demonstrated the deposition of acidic mucopolysaccharide around the hair follicles and toluidine blue staining revealed scattered mast cells in the interstitium. We diagnosed the patient with Morbihan disease (MD). As oral prednisolone at 15 mg/day for 1 month was ineffective, oral doxycycline (DOXY) at 100 mg/day therapy was started. The erythema on both cheeks improved after 3months and his facial symptoms almost disappeared after 12 months. MD is a rare cutaneous disease for which there are no guidelines or standard treatments. Based on our findings and those of 19 MD patients in Japan, granulomas and mast cells on histopathology may be useful indicators for MD treatment. Skin Research, 19 : 217-221, 2020

A 49-year-old man developed dark red erythema in the right inguinal region one month before the first visit. External therapy using steroids and antibiotics was performed for a week without improvement. At the first visit, dark red erythema with a painless ulcer was observed in the right inguinal region, accompanied by lymph node enlargement at the superior side of the nodule. Serological tests for syphilis (RPR, TP) were positive, and the levels of CRP and soluble IL-2 receptor were slightly high. Histopathologically, inflammatory cells, mainly plasma cells, infiltrated the dermis without atypical cells. At this time, primary syphilis was strongly suspected and we confirmed a sexual encounter at a sex trade shop two months before the development of the skin lesion. There was an increased FTA-ABS IgM level and we diagnosed the patient with extragenital chancre. Oral administration of amoxicillin (1,500 mg/day) was started. The skin lesion resolved with scarring and lymph node enlargement disappeared 89 days after the initiation of therapy. Although cases of chancre in the inguinal region are rare, it is important to suspect primary syphilis. Skin Research, 19 : 222-226, 2020

A 13-year-old girl presented with a single 8 mm red-colored, round, firm, painless, mobile nodule on the palmar side of her left ring finger. The overlying epidermis was normal. The lesion developed when she was 3 years old and it gradually increased in size proportional to her growth. Under the clinical suspicion of a neurofibroma, the lesion was surgically excised ; excision was performed to the depth of the superficial fat tissue. Histopathologically, the lesion was an unencapsulated, dense, and fibrous nodule within the dermis composed of a mixture of bland spindled and epithelioid cells with a poor atypical pattern in an extensively hyalinized stroma. A benign spindle cell tumor was diagnosed. Immunohistochemical staining was positive for epithelial membrane antigen, and the patient was diagnosed with sclerosing perineurioma (sclerosing PN) based on her clinical symptoms and pathological findings. Sclerosing PN often grows without pain,and it commonly develops on the fingers and in the palms of young men. Histopathological findings,including those of immunohistochemical staining, are useful for diagnosis. In our case, the clinical characteristics and pathological findings were consistent with the age, site of onset, and size,although it was not considered as a differential diagnosis during the first consultation. In young patients with nodules in the palms and fingers, sclerosing PN should be considered as a differential diagnosis and immunohistochemical staining of tissue sections should be performed. Skin Research, 19 : 227-232, 2020

A 41-year-old woman received radiation therapy for a pituitary tumor at the age of 11 and noted several skin lesions on her head 10 months ago. Clinically, the patient presented with four lesions consisting of small nodules and keratotic erythema. Histopathological examination of the biopsied lesions suggested basal cell carcinoma (BCC). The tumors were resected en bloc with the area treated by radiation therapy. Recently, the number of reported cases of BCC after radiation therapy is increasing. In our case, chronic radiation damage to the skin in addition to the genetic background may have induced multiple BCC lesions on the head. Skin Research, 19 : 233-237, 2020

A 22-year-old man underwent resection of a subcutaneous mass on the back of the neck four years prior to the first visit to our hospital, and he was diagnosed with a hematoma. Three years after the surgery, the patient noted a subcutaneous nodule on the left side of the neck. As it gradually increased in size, the patient visited our hospital. At the first visit, fine-needle aspiration biopsy was performed at the otolaryngology department to make a diagnosis. Approximately 1 week later, the subcutaneous mass rapidly increased in size accompanying severe pain. Hematoma removal was performed at our department for pain relief, followed by total extirpation, including the surrounding granulation tissues and spilt-thickness skin grafting. Histopathological examination revealed a chronic expanding hematoma (CEH). CEHs have been reported to cause secondary soft tissue malignancies. If CEH is suspected, it should be completely resected with the surrounding tissue. As the possibility of chromosomal abnormality as a cause was recently reported, an increase in cases is expected. Skin Research, 19 : 238-243, 2020

Six months ago, a 20-year-old man presenting with cold symptoms was prescribed levofloxacin,loxoprofen sodium (loxoprofen), and mequitazine by his general practitioner (GP). He developed wheals with itching one week later. His GP prescribed cetirizine hydrochloride and the rash disappeared the following day. He took levofloxacin and loxoprofen for cold symptoms again three months later, and developed wheals and dyspnea immediately after. The symptoms resolved after taking cetirizine hydrochloride. Two weeks before being reviewed at our clinic, he took levofloxacin and loxoprofen for cold symptoms a third time. Within 30 minutes, he developed wheals, dyspnea, and nausea. He was brought to the emergency department and treated for anaphylactic reaction. He was subsequently examined at our hospital to determine which medicine caused the allergic reactions. We performed in-hospital scratch testing for levofloxacin,garenoxacin, cefcapene pivoxil, and loxoprofen, and a positive reaction was observed only for levofloxacin. Oral provocation testing for loxoprofen was negative. Based on these results, we diagnosed this patient with anaphylaxis caused by levofloxacin. In this case, skin testing was diagnostic even though the basophil activation test (BAT) for levofloxacin was negative. Low positive rates on skin testing and BAT for immediate-type allergy to quinolones have been reported. Therefore, when skin test results are negative, oral provocation testing is necessary for the accurate diagnosis ofquinolone allergy. Skin Research, 19 : 244-250, 2020

Guselkumab, an anti-interleukin-23 monoclonal antibody, has been used in Japan for psoriasis vulgaris since May 2018, but there are few reports on its effectiveness in clinical practice. As of the end ofMarch 2020, guselkumab was administered to 23 patients (17 males and 6 females) with psoriasis vulgaris. The mean age±standard deviation (SD) ofthese patients was 58.8±13.2 years and the mean duration ofdisease was 18.9±8.3 years. The average skin eruption area before administration ofguselkumab was 19.1±16.1%. The mean psoriasis area and severity index (PASI) score was 15.0±9.9. Nine patients were bio-naïve and 14 were bio-experienced. Guselkumab was the first-line biologic for 9 patients (the bio-naive group), whereas 14 patients previously received other biologics (the bio-experienced group). Ofthe 14 patients in the bio-experienced group, 8 switched from ustekinumab. By the 28th week ofadministration, 69.6% ofthe patients (16/23 patients) achieved a PASI score of75 and 47.8% (11/23 patients) achieved a PASI score of90. In the bio-naive group, 88.9% ofthe patients (8/9 patients) achieved a PASI score of75 and 77.8% (7/9 patients) achieved a PASI score of 90. Regarding adverse effects, the results of T-SPOT.TB tests were interpreted as indeterminate in one case. Although the follow-up period was short and the sample was small, this study suggested that guselkumab is useful for the treatment of psoriasis vulgaris. Skin Research, 19 : 251-256, 2020

A 50-year-old male was referred to us with a one-month history of erythema on the entire body. Nine weeks before the first visit, the patient was administered oral modafinil, flunitrazepam, and chlorpromazine hydrochloride for dysgraphia, and three weeks later, he developed fever and cholestatic hepatopathy. Although these medications were discontinued, hepatic disorder exacerbated and rash developed. Therefore, he was treated by steroid half-pulse therapy (mPSL 500 mg/day, intravenously) for three days followed by oral prednisolone at 20-30 mg/day. Serum HHV-6 and cytomegalovirus DNA were detected. We diagnosed him with drug-induced hypersensitivity syndrome (DIHS). Pneumocystis pneumonia developed 13 weeks afterthe onset of DIHS and he died three weeks later. As Pneumocystis pneumonia and CMV infection are major causes of death in patients with DIHS, clinicians should follow them closely forpneumonia orfungal infection. Skin Research, 19: 257-262, 2020