Background: Prurigo nodularis (PN) is a highly pruritic disease that significantly impairs patient quality of life. Although the mechanism that causes pruritus is not clear, one hypothesis argues that neural hyperplasia, mast cell, and Merkel cell neurite complexes may be associated with PN pathogenesis. Objective: The objective of this study was to analyze whether special staining outcomes differed depending on the presence of atopic dermatitis (AD) and treatment response. Methods: A total of 209 patients diagnosed with PN was analyzed retrospectively. Patients were divided into two groups according to presence or past history of AD and by treatment response. Histopathologic features were obtained using the following stains: Giemsa, S-100, neuron-specific enolase, cytokeratin (CK)-20, CAM5.2, and CK8/CK18. Results: A total of 126 patients (60.29%) had AD, and 68 (32.54%) showed clinical improvement. There were no statistically significant differences in the staining results between the PN groups with AD (PN c̅ AD) and without AD (PN s̅ AD). Additionally, there were no statistically significant differences in staining results between the improved and non-im-proved groups. Conclusion Implementing the special stains helped to identify PN pathogenesis. Because there were no statistically significant differences in the special stain results between the improved and non-improved groups, we conclude that mast cell proliferation, neural hyperplasia, and Merkel cell hyperplasia may not have a significant effect on treatment response.

Background: Scars in children are highly concerning to most parents who usually seek prompt treatment for these lesions. However, compared with adults, children show a greater tendency to develop hypertrophic scars and a higher likelihood of scar widening with increasing age. Objective: We investigated the role of laser treatment for scars in pediatric patients in view of the fact that this approach is challenging in this age group. Methods: This retrospective study included patients aged ＜17 years who visited the Samsung Medical Center between 2013 and 2018 for scar treatment. Of the 28 children who visited the center during this time, 14 presented within 4 to 5 weeks from scar onset and received laser therapy and 14 presented after 4 to 5 weeks and received topical treatment. The Stony Brook Scar Evaluation Scale (SBSES) was used to assess scar formation. Results: The mean initial SBSES scores were lower in the laser than in the topical group (1.93±0.92 vs. 2.71±0.83, p=0.0363). No intergroup difference was observed in SBSES scores upon treatment completion (4.50±0.94 vs. 4.21±1.19, p=0.4673). Multivariable analysis after adjustment for age, sex, and initial SBSES scores showed that the type (laser vs. topical) of treatment was not significantly associated with an SBSES score=5 or duration of treatment. Conclusion Laser intervention may be useful for scar therapy in children who present early and can receive prompt treatment before scar maturation; however, further studies are warranted to validate our results.

Background: Scars in children are highly concerning to most parents who usually seek prompt treatment for these lesions. However, compared with adults, children show a greater tendency to develop hypertrophic scars and a higher likelihood of scar widening with increasing age. Objective: We investigated the role of laser treatment for scars in pediatric patients in view of the fact that this approach is challenging in this age group. Methods: This retrospective study included patients aged ＜17 years who visited the Samsung Medical Center between 2013 and 2018 for scar treatment. Of the 28 children who visited the center during this time, 14 presented within 4 to 5 weeks from scar onset and received laser therapy and 14 presented after 4 to 5 weeks and received topical treatment. The Stony Brook Scar Evaluation Scale (SBSES) was used to assess scar formation. Results: The mean initial SBSES scores were lower in the laser than in the topical group (1.93±0.92 vs. 2.71±0.83, p=0.0363). No intergroup difference was observed in SBSES scores upon treatment completion (4.50±0.94 vs. 4.21±1.19, p=0.4673). Multivariable analysis after adjustment for age, sex, and initial SBSES scores showed that the type (laser vs. topical) of treatment was not significantly associated with an SBSES score=5 or duration of treatment. Conclusion Laser intervention may be useful for scar therapy in children who present early and can receive prompt treatment before scar maturation; however, further studies are warranted to validate our results.

Background: Prurigo nodularis (PN) is a highly pruritic disease that significantly impairs patient quality of life. Although the mechanism that causes pruritus is not clear, one hypothesis argues that neural hyperplasia, mast cell, and Merkel cell neurite complexes may be associated with PN pathogenesis. Objective: The objective of this study was to analyze whether special staining outcomes differed depending on the presence of atopic dermatitis (AD) and treatment response. Methods: A total of 209 patients diagnosed with PN was analyzed retrospectively. Patients were divided into two groups according to presence or past history of AD and by treatment response. Histopathologic features were obtained using the following stains: Giemsa, S-100, neuron-specific enolase, cytokeratin (CK)-20, CAM5.2, and CK8/CK18. Results: A total of 126 patients (60.29%) had AD, and 68 (32.54%) showed clinical improvement. There were no statistically significant differences in the staining results between the PN groups with AD (PN c̅ AD) and without AD (PN s̅ AD). Additionally, there were no statistically significant differences in staining results between the improved and non-im-proved groups. Conclusion Implementing the special stains helped to identify PN pathogenesis. Because there were no statistically significant differences in the special stain results between the improved and non-improved groups, we conclude that mast cell proliferation, neural hyperplasia, and Merkel cell hyperplasia may not have a significant effect on treatment response.

A capillary hemangioma is a vascular tumor with small capillary sized vascular channel. Multiple capillary hemangioma in relation with drugs have been rarely reported. Here in, we report a case of multiple capillary hemangioma in patient diagnosed with chronic myeloid leukemia who received tyrosine kinase inhibitors (TKIs). Histopathological findings have shown capillary proliferation in the upper dermis, which is consistent with capillary hemangioma. Since TKIs can paradoxically activate the MEK/ERK pathway which is required for angiogenesis, we presumed that the lesions as the cutaneous side effects of TKIs.

Onychogryphosis is a disorder of nail plate growth, which most commonly involves the toenails. It is characterized by opaque, yellow-brown thickening of the nail plate with associated marked convexity and elongation. Treatment for onychogryphosis can be conservative or operative depending on the cause and medical status of the patient. A 30-year-old male presented with onychogryphosis of the right and left toenails. Since the patient had shown recurrence after simple nail avulsion several years ago, the inverted T incision method and fusiform excision of the hypertrophic hyponychium were performed. No recurrence was observed during the 3-year follow-up period. Our results showed that nail avulsion combined with traction osteophyte removal is a suitable surgical method for treating onychogryphosis.

Bullous pemphigoid (BP) is a chronic and recurrent bullous disorder that may be associated with the administration of certain drugs. Recently, bullous cutaneous adverse events after immunotherapy (IT) or targeted therapy have been increasingly reported. Here, we report a case of BP in a patient diagnosed with metastatic melanoma after treatment with pembrolizumab, dabrafenib, and trametinib. Histopathological examination showed a subepidermal blister with perivascular lymphocytic and eosinophilic infiltration; the accompanying findings of linear immunoglobulin G and C3 deposition by immunofluorescence microscopy were consistent with BP. Since IT agents may initiate immune dysregulation and pathologic autoantibody production, which are required for the pathogenesis of BP, the lesions were thought to be cutaneous adverse events caused by IT.

Background: Intradermal injection of botulinum toxin A (BTXA) is used for cosmetic purposes without strong evidence for clinical use, as opposed to intramuscular injection. Objective: To evaluate the efficacy and safety of intradermal injection of incobotulinum toxin A (iBTXA) in the cheeks. Methods: We conducted a study with 18 volunteers who received intradermal injection of iBTXA into one cheek and normal saline into the contralateral side as a control. Volunteers visited the clinic at weeks 2, 4, 8, and 12 after injection. At each visit, pores and wrinkles were evaluated by a facial analyzer, sebum secretion by a sebumeter, skin texture by both volunteers and clinicians, and wrinkles of the nasolabial fold were graded with photographic reviews. Results: There were no significant effects on the wrinkles of the infraorbital area and sebum secretion. However, there were significant improvements in the wrinkles of the nasolabial fold and skin texture on the iBTXA injected side. The effects on the wrinkles of the nasolabial fold lasted 12 weeks, and those on skin texture lasted 8 weeks. Improvement in the pore size was observed only at week 2. No serious adverse events were reported except one volunteer who complained of facial palsy after the injection of 30 units of iBTXA in one cheek. However, injection of 20 units of iBTXA in one cheek was not associated with any adverse events. Conclusion Intradermal injection of iBTXA, could provide clinical benefits for skin texture and wrinkles overcoming the skin prick effect without obvious side effects.

A capillary hemangioma is a vascular tumor with small capillary sized vascular channel. Multiple capillary hemangioma in relation with drugs have been rarely reported. Here in, we report a case of multiple capillary hemangioma in patient diagnosed with chronic myeloid leukemia who received tyrosine kinase inhibitors (TKIs). Histopathological findings have shown capillary proliferation in the upper dermis, which is consistent with capillary hemangioma. Since TKIs can paradoxically activate the MEK/ERK pathway which is required for angiogenesis, we presumed that the lesions as the cutaneous side effects of TKIs.