Sung Ku Ahn

Yonsei University Hospital, Sŏul, Seoul, South Korea

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Publications (41)77.83 Total impact

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    Annals of Dermatology 04/2014; 26(2):264-6. · 0.61 Impact Factor
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    Annals of Dermatology 11/2013; 25(4):518-20. · 0.61 Impact Factor
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    Annals of Dermatology 11/2013; 25(4):512-4. · 0.61 Impact Factor
  • Hyunjoong Jee, Noo Ri Lee, Sung Ku Ahn
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    ABSTRACT: Reports of seborrheic keratosis (SK) with concurrent malignant tumors are rare, but previous and recent reports - especially the co-manifestation of basal cell carcinomas (BCC) have added to the ongoing debate of the possibility of the development of BCC from SK. We report a rare case of SK with underlying BCC with scarcely accounted histopathological characteristics - reticulated type and nodular type, respectively - that showed no direct histological link between the two entities. We also carefully suggest that differences in histopathology (whether the two lesions are connected or not) may account for the possibility of incidental co-habitation.
    The Journal of Dermatology 08/2013; · 1.77 Impact Factor
  • International journal of dermatology 06/2013; · 1.18 Impact Factor
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    ABSTRACT: Despite the increasing use of topical tacrolimus, there is little information about its effect on skin wound healing. To determine effects on acute cutaneous wound healing, two full-thickness skin wounds were imparted on the backs of 45 hairless mice, which were then divided into vehicle-, topical tacrolimus- and topical steroid-treated group. Each drug was topically applied once daily. The wound area was assessed by using dermoscopic images every two days after wounding. At 3, 7 and 11 days after wounding, 10 wounds in each group were collected for semi-quantitative analysis of histological features including re-epithelialization, polymorphonuclear leucocytes, fibroblasts and collagen. We also checked the mRNA expression levels of EGF, TGF-β, TNF-α and IL-1α. While topical application of clobetasol propionate was found to delay re-epithelialization and infiltration of polymorphonuclear leucocyte, topical treatment with tacrolimus showed patterns similar to that of the vehicle. In the tacrolimus-treated group, mRNA expression levels of IL-1α and TGF-β were slightly decreased, while the others were similar with the vehicle-treated group. Unlike steroid, topical tacrolimus, therefore, did not disturb the wound healing process in a murine skin wound model.
    Experimental Dermatology 05/2013; 22(5):369-71. · 3.58 Impact Factor
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    ABSTRACT: Topical steroid treatment induces diverse local Wand systemic adverse effects. Several approaches have been tried to reduce the steroid-induced adverse effects. Simultaneous application of physiological lipid mixture is also suggested. Novel vehicles for topical glucocorticoids formulation were evaluated for the efficacy of reducing side-effects and the drug delivery properties of desonide, a low potency topical steroid. Transcutaneous permeation and skin residual amount of desonide were measured using Franz diffusion cells. The anti-inflammatory activity was evaluated using murine model. Topical steroids formulation containing desonide, in either cream or lotion form, were prepared using multi-lamellar emulsion (MLE), and conventional desonide formulations were employed for comparison. MLE formulations did not affect the anti-inflammatory activity of the desonide in phobol ester-induced skin inflammation model, compared with conventional formulations. While the penetrated amounts of desonide were similar for all the tested formulations at 24 hours after application, the increased lag time was observed for the MLE formulations. Interestingly, residual amount of desonide in epidermis was significantly higher in lotion type MLE formulation. Steroid-induced adverse effects, including permeability barrier function impairment, were partially prevented by MLE formulation. Topical desonide formulation using MLE as a vehicle showed a better drug delivery with increased epidermal retention. MLE also partially prevented the steroid-induced side effects, such as skin barrier impairment.
    Annals of Dermatology 02/2013; 25(1):5-11. · 0.61 Impact Factor
  • International journal of dermatology 12/2012; · 1.18 Impact Factor
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    ABSTRACT: Nevus sebaceous (NS) is a type of classical nevus or congenital malformation that is often present at birth and commonly involves the scalp or face. The lesion usually presents as a linear, yellow, hairless, and verrucous plaque. It has been well-established that several benign and malignant tumors can develop from the NS; however, there have been no reports about ectopic fat cells in the dermis, and cornoid lamella arising from the NS. We report a case of NS on the scalp with accompanying unusual histopathologic findings.
    Annals of Dermatology 10/2011; 23(Suppl 2):S231-4. · 0.61 Impact Factor
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    ABSTRACT: A mucocele is a common, benign lesion of the oral cavity that develops following the extravasation or retention of mucous from a major or minor salivary gland. A pyogenic granuloma (PG) is also a common, benign condition characterized by proliferating capillaries that affect the skin and mucous membranes. The concurrent occurrence of a mucocele and a PG lesion has rarely been reported in the medical literature. This case study reports such a finding in a 16-year-old patient who presented to our department.
    Annals of Dermatology 09/2011; 23 Suppl 1:S108-10. · 0.61 Impact Factor
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    ABSTRACT: There has been little research on extramammary Paget's disease (EMPD) conducted in Asia. The aim of this multicenter study was to investigate the clinicopathological features, biological behavior, and treatment of EMPD in 194 Korean patients over a five-year period. As expected, this disease exhibited a male dominance (3.9:1) pattern. To distinguish the true association of malignancy with EMPD from coincidental occurrence of malignancy, we modified Chanda's guidelines. This analysis determined that there was an accompanying malignancy in 26 patients (14.4%), which included stomach (six cases), rectum (three cases), and colon (three cases) malignancies. With regard to treatment, 112 patients (58%) underwent conventional excisions, and 22 (11.4%) had Mohs surgery. Follow-up data for periods of 3-180 months were available for 147 patients; these data indicated that 42 patients (28.6%) experienced local recurrences. Patients who underwent Mohs micrographic surgery experienced a lower rate of recurrence (12.5%) than patients who underwent conventional excision (33.3%). In summary, this Korean population-based study demonstrated that the clinical features of EMPD, such as gender predominance, are consistent with reports from other Asian population-based studies. However, this study additionally demonstrated that the rate of association with malignancy in the Korean population (14.4%) was higher than that observed in other Asian studies.
    International journal of dermatology 05/2011; 50(5):508-15. · 1.18 Impact Factor
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    ABSTRACT: Various therapeutic approaches have been suggested for preventing or reducing the adverse effects of topical glucocorticoids, including skin barrier impairment. Previously, we have shown that impairment of skin barrier function by the highest potency topical glucocorticoid, clobetasol 17-propinate (CP), can be partially prevented by co-application of a physiological lipid mixture containing pseudoceramide, free fatty acids, and cholesterol (multi-lamellar emulsion [MLE]). Skin atrophic effects of CP were also partially reduced by MLE. In this study, the preventive effects of MLE on the lowest potency topical glucocorticoid, hydrocortisone (HC), were investigated using animal models. Anti-inflammatory activity of topical HC was evaluated using a 12-O-tetradecanoylphobol-13-acetate-induced skin edema model. Topical steroid induced adverse effects were evaluated using hairless mouse. The results showed that the anti-inflammatory activity was not altered by co-application of either MLE or hydrobase. However, co-application of MLE and 1.0% HC showed less impairment in the epidermal permeability barrier function, skin hydration, and skin surface pH compared with hydrobase. Stratum corneum integrity, evaluated by measuring trans-epidermal water loss after repeated tape stripping, showed less damage with MLE co-application. Long-term application of topical HC induced skin atrophy, measured by a reduction in skinfold and epidermal thickness and in the number of epidermal proliferating cell nucleus antigen (PCNA)-positive keratinocytes. Co-application of MLE did not affect the skinfold or epidermal thickness, but the number of PCNA-positive keratinocytes was less decreased with MLE use. These results suggest that co-application of MLE is effective in reducing the local adverse effects of low-potency topical glucocorticoids and supports the therapeutic efficacy of physiological lipid mixtures on skin barrier function.
    Allergy, asthma & immunology research 04/2011; 3(2):96-102. · 2.65 Impact Factor
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    ABSTRACT: Acupuncture and cupping have a public reputation as being safe even though these practices can lead to complications such as trauma or infection. We report here on a case of herpes simplex virus (HSV) infection secondary to acupuncture and cupping in a 56-year-old woman. The patient, who had a history of acupuncture and cupping on her left forearm for treating her myalgia, developed painful papules. Histologically, the biopsy specimen showed characteristic ballooning degeneration and inclusion bodies in the epidermis and mid-dermis. These clinical and histological findings were consistent with the diagnosis of HSV infection.
    Annals of Dermatology 02/2011; 23(1):67-9. · 0.61 Impact Factor
  • European journal of dermatology: EJD 01/2011; 21(1):106-7. · 1.76 Impact Factor
  • The Journal of Dermatology 11/2010; 38(5):510-3. · 1.77 Impact Factor
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    ABSTRACT: Superficial acral fibromyxoma (SAFM) is a rare myxoid tumor that was first described in 2001. The presence of a very slow growing solitary tender mass in the subungual area is the typical clinical feature at presentation. Histopathologically, SAFM is composed of stellate cells in a myxocollagenous matrix with a poorly circumscribed margin. This tumor is thought to be benign, but its natural course is not fully understood. We describe a 15-year-old patient with recurrent SAFM and discuss the proper treatment and follow up.
    Annals of Dermatology 02/2010; 22(1):110-3. · 0.61 Impact Factor
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    ABSTRACT: Low-frequency sonophoresis (LFS) has been shown to disrupt the structure of stratum corneum (SC) lipid bilayers and enhance SC permeability. In this study, we examined the penetration pathway of lanthanum nitrate (LaNO(3)) tracer in viable epidermis after combined treatment of LFS and tape stripping (TS), as a physical enhancer, or oleic acid (OA) application, as a chemical enhancer, using transmission electron microscopy (TEM). As a positive control, we visualized the passive diffusion pathway of LaNO(3) and iron oxide (Fe(3)O(4)) nanoparticles after the incision of hairless mouse skin. Next, we applied LFS immediately after TS or OA application and visualized the penetration pathway of LaNO(3). Each treatment showed restricted penetration to the SC-stratum granulosum (SG) interface or upper SG layer. However, the additional application of LFS induced diffuse intracellular distribution of LaNO(3) throughout the viable epidermis. Quantitative analysis also revealed that combined treatment significantly increases LaNO(3) penetration into viable epidermis when compared with each treatment. Our ultrastructural findings show the synergistic effect of LFS and TS or OA application on transdermal drug delivery. We also found that this combined treatment enhances the penetration of LaNO(3) through the viable epidermis through an intracellular pathway.
    Journal of Investigative Dermatology 11/2009; 130(4):1063-72. · 6.19 Impact Factor
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    ABSTRACT: Membranous lipodystrophy is characterized by the presence of microcysts lined by amorphous, eosinophilic material with an arabesque appearance. We experienced a case of a 72-year-old man who had dark brownish, pruritic papules on the arms, legs, and back. Histopathologic examination of a biopsied lesion showed homogeneous, eosinophilic material in the papillary dermis, as well as membranous lipodystrophy. We report a case of membranous lipodystrophy observed in lichen amyloidosis.
    Annals of Dermatology 05/2009; 21(2):174-7. · 0.61 Impact Factor
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    ABSTRACT: Cherry angiomas are a common cutaneous vascular proliferation which manifests as single or multiple spots and occurs predominantly on the upper trunk and arms. They typically appear as round-to-oval, bright, red, dome-shaped papules and pinpoint macules measuring up to several millimeters in diameter. The histopathologic findings of a cherry angioma are consistent with a true capillary hemangioma, which is formed by numerous, newly developed capillaries with narrow lumens and prominent endothelial cells arranged in a lobular fashion in the papillary dermis. Herein, we report a case of multiple cherry angiomas on the scalp, an uncommon location for cherry angiomas.
    Case Reports in Dermatology 01/2009; 1(1):82-86.
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    ABSTRACT: Protease-activated receptor-2 (PAR-2) is known to be involved in epidermal permeability barrier function homeostasis. PAR-2 activation occurs after barrier disruption and further activation of PAR-2 by activating peptide significantly delays barrier recovery rate. Cockroach and house dust mite allergens, both known to be associated with the development of asthma, allergic rhinitis, and atopic dermatitis, have protease activity, which can activate PAR-2. In this study, we investigated the effects of both allergens on the epidermal barrier function as well as on the epidermal calcium gradient. Both allergens, when topically applied on the barrier-disrupted site, increased protease activities in the epidermis and delayed barrier recovery and lamellar body secretion in murine skin. The topical application of PAR-2-specific antagonist or protease inhibitors normalized the barrier recovery. Cockroach allergens induced intracellular calcium oscillations in cultured human keratinocytes through PAR-2-involved pathway, which was confirmed by desensitization protocol. Abnormal calcium ion distribution after barrier disruption was also observed in allergens-applied skin. These results suggest that allergens with protease activity can influence the epidermal permeability barrier homeostasis through PAR-2 activation and consequent modulation of the calcium ions in skin.
    Journal of Investigative Dermatology 09/2008; 128(8):1930-9. · 6.19 Impact Factor

Publication Stats

233 Citations
77.83 Total Impact Points

Institutions

  • 1994–2014
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2011
    • Seoul Medical Center
      Sŏul, Seoul, South Korea
  • 2002–2011
    • Yonsei University
      • Department of Dermatology
      Seoul, Seoul, South Korea
  • 2010
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea
  • 2008
    • University of Ulsan
      Urusan, Ulsan, South Korea