Background: The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. Results: K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. Conclusion Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Spindle cell squamous cell carcinoma (SCSCC) is relatively uncommon, but may be encountered. It poses a challenge in the differential diagnosis in that it includes other spindle cell neoplasms. An 81-year-old female with a raised and exophytic plaque with central ulceration surrounding erythematous patches of the left lower extremities, which was gradually and very slowly increasing in size was admitted to our hospital. After resection, conventional histopathological investigation showed spindle-shaped cells showing hyperchromatic nuclei and mitosis, infiltrating the dermis in a storiform pattern. Immunohistochemical analysis revealed that SCSCC was positive for cytokeratins (AE1/AE3, CAM 5.2, 34betaE12) and mesenchymal markers (vimentin, SMA), but was negative for p63, CD34, CD68, melan A and S-100.
Carcinoma, Squamous Cell ; Dermis ; Diagnosis, Differential ; Female ; Humans ; Keratins ; Leg ; Lower Extremity ; MART-1 Antigen ; Mitosis ; Ulcer

BACKGROUND: The major limitations of the current therapeutic treatments for onychomycosis are the recurrence of the infection and the duration of the treatment. Recently, photodynamic therapy (PDT) is thought to be a novel alternative method for treatment of onychomycosis. OBJECTIVE: The aim of this study is to investigate the efficacy and safety of PDT with methyl 5-aminolevulinic acid (MAL) for the treatment of onychomycosis. METHODS: We performed MAL-PDT in eight patients with distal subungual onychomycosis on at least one great toenail. After the total three treatments, we observed the clinical and mycological courses for twelve months. RESULTS: For the twelve months of follow-up period, three patients (37.5%) showed continuous clinical improvement, two patients (25%) aggravation after transient improvement, and the rest, three patients (37.5%) resistance to treatment. All subjects complained of quite severe burning pain during irradiation of light source. CONCLUSION: In this study, we observed the highly variable clinical and mycological results of PDT in onychomycosis. We concluded that it is too difficult to consistently achieve the best fungicidal effect by PDT without strictly selected conditions.
Burns ; Follow-Up Studies ; Humans ; Light ; Nails ; Onychomycosis ; Photochemotherapy ; Recurrence ; Triazenes

Fibroepithelioma of Pinkus is generally accepted as a low-risk variant of basal cell carcinoma. A 66-year-old man was presented with a solitary dark red nodule with superficial erosion on his right groin. It tended to bleed, but was otherwise asymptomatic. Histopathologically, the tumor was composed of long, thin, branching and anastomosing strands of basaloid cells, which extends from the epidermis into the fibromucinous stroma. Basaloid tumor cells were palisaded at the periphery of the strands, and small buds were seen projecting from the epithelial strands. Significant amounts of melanin pigment were deposited in the papillary and reticular dermis, and the stroma between the tumor cords and also inside the tumor cells. The lesion was completely excised with clear margin. We report a case of pigmented fibroepithelioma of Pinkus with review of the literature in this communication.
Aged ; Carcinoma, Basal Cell ; Dermis ; Epidermis ; Groin ; Humans ; Melanins

Herpes zoster duplex, particularly herpes zoster duplex symmetricus, is a very rare manifestation of herpes zoster that occurs in immunocompetent patients. A 23-year-old Korean man presented with grouped erythematous, ruptured, crusted vesicles on plaques and papules on his forehead and both temporal areas. He had unexplained pain around the cutaneous lesions for the past 2 weeks, and the vesicles developed 1 week ago. A Tzanck smear test of the skin lesion showed multinucleated giant cells. A punch biopsy taken from the vesicle on the forehead revealed an intraepidermal vesicle with acantholysis and balloon cells at the floor of the vesicle. He was diagnosed with herpes zoster involving bilateral dermatomes.
Acantholysis ; Biopsy ; Floors and Floorcoverings ; Forehead ; Giant Cells ; Herpes Zoster ; Humans ; Skin ; Young Adult

Confluent and reticulated papillomatosis (CRP) was first described as a relatively rare dermatosis. CRP is characterized by slightly hyperkeratotic pigmented papules that are confluent in the center and reticulated at the periphery, located on the neck, abdomen, intermammary, and interscapular regions. Histopathologically, lesions typically reveal orthohyperkeratosis, papillomatosis, and focal acanthosis. A 20-year-old man presented with a 2-year history of slightly pruritic lesions on the chest, abdomen, back, and upper extremities. The lesions were brownish papules and plaques in a reticulated and coalescing pattern. Histologically, a basket-weave pattern of orthohyperkeratosis and mild acanthosis were seen. However, there was no significant papillomatosis, even in multiple sections. Periodic acid Schiff stain was negative for fungi. The patient was treated with doxycycline, 200 mg daily, for 4 weeks. The lesions completely resolved and did not recur during 12 months of follow-up. We report a rare case of CRP without papillomatosis.
Abdomen ; Doxycycline ; Follow-Up Studies ; Fungi ; Humans ; Neck ; Papilloma ; Periodic Acid ; Skin Diseases ; Thorax ; Upper Extremity ; Young Adult

Malignant syphilis (also known as lues maligna) is a rare dermatologic manifestation of syphilis and this is more commonly seen in patients with human immunodeficiency virus (HIV) infection. A 40-year-old man presented with general malaise and widespread cutaneous noduloulcerative lesions covered with lamellar crusts for 15 days. He had been diagnosed with HIV infection 6 years earlier, but had not regularly taken antiretroviral drugs. The syphilis serology showed a VDRL (venereal disease research laboratory) titer of 1 : 256 and a positive TPPA (treponema pallidum particle agglutination test) at presentation. Histologic exam showed the dense perivascular inflammatory infiltrates composed of lymphocytes, histiocysts and neurophils with some plasma cells in the underlying upper and reticular dermis. Obliterated blood vessels with eosinophilic materials were observed as an unusual histologic feature of syphilis. Based on the clinical, histological and serological findings, a diagnosis of malignant syphilis accompanied by acquired immune deficiency syndrome (AIDS) was made. The patient was treated with intramuscular benzathine penicillin G at 2.4 million units per week for 3 weeks, and the skin lesions completely healed with post-inflammatory hyperpigmentation. It is necessary to take into account this entity among the possible diagnoses in HIV-infected patients with cutaneous noduloulcerative lesions.
Acquired Immunodeficiency Syndrome ; Adult ; Agglutination ; Blood Vessels ; Dermis ; Eosinophils ; Ethylenediamines ; HIV ; HIV Infections ; Humans ; Hyperpigmentation ; Lymphocytes ; Penicillin G Benzathine ; Plasma Cells ; Skin ; Syphilis

Trichilemmoma is a benign, solitary, small tumor that might often be misdiagnosed as a basal cell carcinoma or verruca. It is usually seen on the face, and especially on the nose and cheeks. A 79-year-old Korean man presented with a 2.0x2.0 cm-sized nodular mass on his right shoulder and the lesion was histopathologically diagnosed as a trichilemmoma. The atypical clinical appearance and localization of his neoplasm did not help us diagnose the lesion, and the histological findings were the only clues for making the diagnosis of trichilemmoma.
Aged ; Carcinoma, Basal Cell ; Cheek ; Humans ; Nose ; Shoulder ; Warts

BACKGROUND: Chronic urticaria (CU) is one of the most common skin disorders. This disease commonly induces emotional, social and psychological problems due to the erythematous lesion and intense pruritus. But there has been inadequate objective evaluation of the quality of life (QOL) of the patients with CU in Korea. OBJECTIVE: The purpose of this study was to investigate the QOL of the Korean patients with CU by means of a new disease-specific tool and to assess the association between the QOL and the severity of disease. METHODS: A total of 118 patients with CU were interviewed using the CU QOL questionnaire (CU-Q2oL). Their symptoms were evaluated with the urticaria severity score. We analyzed the relationship between the severity score and the CU-Q2oL score with Pearson's correlation test. RESULTS: The average score of the CU-Q2oL was 50.08+/-18.68. It was high when the patients had high severity scores (p<0.01). The severity score was increased in the patients with old age and when they were married. Comorbid systemic and skin diseases, a long duration of urticaria and systemic symptoms accompanying urticaria were also related to a high severity score. CONCLUSION: This study showed that CU has a significant impact on the QOL of Korean patients with CU in proportion to the disease severity. Clinicians need to consider the QOL and the CU severity of their patients to achieve the ideal goals of treatment.
Humans ; Korea ; Pruritus ; Quality of Life ; Skin ; Skin Diseases ; Urticaria ; Surveys and Questionnaires

We present a case of accessory tragus (AT) which developed at an unusual site, the nasal vestibule, of a 1-day-old girl. To our knowledge, this is the first report of an accessory tragus that appears on the nasal vestibule.