The skin is the first line of defense of our body, and it is composed of the epidermis and dermis with diverse immune cells. Various in vitro models have been investigated to recapitulate the immunological functions of the skin and to model inflammatory skin diseases. The simplest model is a two-dimensional (2D) co-culture system, which helps understand the direct and indirect cellto-cell interactions between immune and structural cells; however, it has limitations when observing three-dimensional (3D) interactions or reproducing skin barriers. Conversely, 3D skin constructs can mimic the human skin characteristics in terms of epidermal and dermal structures, barrier functions, cell migration, and cell-to-cell interaction in the 3D space. Recently, as the importance of neuro-immune-cutaneous interactions in the inflammatory response is emerging, 3D skin constructs containing both immune cells and neurons are being developed. A microfluidic culture device called “skin-on-a-chip,” which simulates the structures and functions of the human skin with perfusion, was also developed to mimic immune cell migration through the vascular system. This review summarizes the in vitro skin models with immune components, focusing on two highly prevalent chronic inflammatory skin diseases: atopic dermatitis and psoriasis. The development of these models will be valuable in studying the pathophysiology of skin diseases and evaluating the efficacy and toxicity of new drugs.

The skin is the first line of defense of our body, and it is composed of the epidermis and dermis with diverse immune cells. Various in vitro models have been investigated to recapitulate the immunological functions of the skin and to model inflammatory skin diseases. The simplest model is a two-dimensional (2D) co-culture system, which helps understand the direct and indirect cellto-cell interactions between immune and structural cells; however, it has limitations when observing three-dimensional (3D) interactions or reproducing skin barriers. Conversely, 3D skin constructs can mimic the human skin characteristics in terms of epidermal and dermal structures, barrier functions, cell migration, and cell-to-cell interaction in the 3D space. Recently, as the importance of neuro-immune-cutaneous interactions in the inflammatory response is emerging, 3D skin constructs containing both immune cells and neurons are being developed. A microfluidic culture device called “skin-on-a-chip,” which simulates the structures and functions of the human skin with perfusion, was also developed to mimic immune cell migration through the vascular system. This review summarizes the in vitro skin models with immune components, focusing on two highly prevalent chronic inflammatory skin diseases: atopic dermatitis and psoriasis. The development of these models will be valuable in studying the pathophysiology of skin diseases and evaluating the efficacy and toxicity of new drugs.

Sarcoidosis is a multisystem granulomatous disease of unknown etiology. A range of factors including tuberculous infection, beryllium exposure, and cold climate have been implicated in the pathogenesis of the condition. A 45-year-old woman presented with a 4-month history of an asymptomatic eyelid swelling and multiple erythematous papules on the neck. Histological examination of the neck, orbital soft tissue, and lacrimal gland was consistent with sarcoidosis. Ziehl−Neelsen stains and polymerase chain reactions (PCRs) for tuberculosis on the skin biopsy specimens were negative. However, the orbital soft tissue specimen was positive for non-tuberculous mycobacteria (NTM) PCR. The patient was finally diagnosed with sarcoidosis associated with NTM. Treatment with systemic steroid and hydroxychloroquine was started, resulting in an improvement of skin lesions. We herein report a case of sarcoidosis associated with NTM infection with review of the literature, as only little is known regarding the role of mycobacteria in sarcoidosis.

BACKGROUND: Growth factors play important roles in wound healing. However, the evidence for the effects of growth factors on post-thyroidectomy scars is limited. OBJECTIVE: We performed a prospective study to assess the preventive and therapeutic effect of a multi-growth factor (MGF)-containing cream on post-thyroidectomy scars. METHODS: Twenty-one patients with thyroidectomy scars applied MGF cream twice a day. We assessed the changes in erythema, pigmentation, skin elasticity, and skin hydration status using the erythema index, melanin index, cutometer, and corneometer, respectively. In addition, Vancouver scar scale (VSS) and patient satisfaction were assessed at 10 days after surgery (baseline), 2 weeks, 6 weeks, and 12 weeks after baseline. RESULTS: The mean total VSS scores were significantly lower at 6 weeks (3.24±1.51 vs. 1.91±1.38) and 12 weeks (3.24±1.51 vs. 1.71±1.59) compared to the baseline. The degree of pigmentation was significantly lower at 12 weeks compared to the baseline, and the skin elasticity, and the skin hydration status were significantly higher at 12 weeks compared to the baseline. Over 85% of the patients were satisfied with the use of MGF cream without any adverse effect. CONCLUSION: MGF cream might have additive or supportive effect for scar formation after thyroidectomy.
Cicatrix* ; Elasticity ; Erythema ; Humans ; Intercellular Signaling Peptides and Proteins ; Melanins ; Patient Satisfaction ; Pigmentation ; Prospective Studies ; Skin ; Skin Pigmentation ; Thyroidectomy ; Wound Healing

A giant cell tumor of tendon sheath is a slow growing benign soft tissue tumor that is known by a variety of names including fibrous histiocytoma of tendon sheath and fibrous xanthoma of the synovium. Clinically, it presents as a 1~3 cm firm, non-mobile, painless, nontender mass, and mostly occurs at interphalangeal joints of fingers. It shows female predominance and can occur at any age, but it is most common between the third and fifth decades and is rare in children. We now report the case of a 10-year-old girl with a giant cell tumor of tendon sheath on the toe.
Child ; Female ; Fingers ; Giant Cell Tumors ; Giant Cells ; Histiocytoma, Benign Fibrous ; Humans ; Joints ; Synovial Membrane ; Tendons ; Toes ; Xanthomatosis

BACKGROUND: Biodegradable microneedle technology is a recently developed method to deliver medical and pharmaceutical medications into the skin, and is expected to yield better treatment results than topical application methods. OBJECTIVE: To evaluate the efficacy of hyaluronic acid (HA)-based microneedle patches and epidermal growth factor (EGF)-containing microneedle patches on periorbital wrinkle improvement. METHODS: A 20-week randomized, double-blind study was performed. Twenty-five Korean patients with periorbital wrinkles and a wrinkle severity rating scale (WSRS) score above 2 were enrolled into the study. The patients completed the study using the two different types of patches on each side of the designated periorbital wrinkles area every other day for 8 weeks. Patients were requested for an additional 12-week follow up. Wrinkle improvements were assessed by WSRS score, subjective patient satisfaction score, and imaging analysis using the visiometer, corneometer, cutometer, and mexameter, respectively (Courage&Khazaka, Cologne, Germany). RESULTS: Both the HA-based microneedle patch and EGF-containing HA-based microneedle patch had positive effects on WSRS score, patient satisfaction levels, and corneometer result with statistically significant differences. No significant side effects were noticed. CONCLUSION: With respect to efficacy, no statistical difference between the two groups were noted, indicating that the anti-wrinkle effects of the microneedle patch may solely be due to the HA rather than the EGF.
Double-Blind Method ; Epidermal Growth Factor ; Follow-Up Studies ; Humans ; Hyaluronic Acid ; Patient Satisfaction ; Skin

Pembrolizumab is an immune checkpoint inhibitor that selectively blocks the programmed cell death (PD)-1 receptor. Although it has a dramatic effect on the treatment of advanced malignancies, instability of immune tolerance may cause immune-related adverse events in the skin. A 62-year-old male with a history of metastatic urothelial carcinoma was referred to the dermatology department and presented with a widespread mucocutaneous rash. Itching appeared 7 days after the first administration of pembrolizumab, and on the third day after the second administration, an erythematous maculopapular rash that coalesced into large flaccid bullae on the whole body with a positive Nikolsky’s sign developed. A biopsy revealed a subepidermal bulla with basal keratinocyte necrosis. Pembrolizumab was discontinued due to the diagnosis of toxic epidermal necrolysis (TEN), and intravenous methylprednisolone was started. Herein, we report a case of TEN induced by pembrolizumab to highlight immune-related cutaneous adverse events in patients receiving anti-PD-1 therapy.

Background: Vulvar pruritus is a common complaint among women presenting to dermatologists. However, few studies have analyzed the dermatologic conditions that cause it. Objective: This retrospective study aims to evaluate the clinical features and causes of pruritic skin lesions of the female external genitalia. Methods: This study included 161 female patients with vulvar pruritus between 2008 and 2018 at CHA Bundang Medical Center. Data were collected by reviewing the electronic medical records retrospectively. The age, diagnosis, and histopathologic findings of the patients were reviewed. Results: The patients’ mean age was 49 years. On physical examination, 71.4% of patients (n=115) had definite skin lesions, and 28.6% (n=46) had ‘vulvar pruritus without skin rash’. The most common diagnostic category, confirmed by skin biopsy, was inflammatory dermatoses (53.4%, n=86), including lichen sclerosus et atrophicus, lichen simplex chronicus, nonatopic eczema, atopic eczema, and psoriasis. Moreover, 7.5% of patients (n=12) were diagnosed with infectious diseases, including candidiasis, herpes simplex virus, syphilis, and scabies; 5.6% (n=9) were diagnosed with neoplastic diseases, including vulvar intraepithelial neoplasia, squamous cell carcinoma, extramammary Paget’s disease, and Bowen’s disease. Conclusion The causes of vulvar itch are vast, and often, multiple causes coexist simultaneously. Therefore, it requires a systemic approach to establish the correct diagnosis. Dermatologists should actively participate in the diagnosis and treatment.