Sang Min Hwang

The pretreatment effect of chemical skin penetration enhancers in transdermal drug delivery using iontophoresis.

The transdermal drug delivery (TDD) system has largely been divided into physical, biochemical and chemical methods. Recently, combinations of these methods were introduced for more effective delivery with less side effects. We performed this study to identify the effectiveness and mechanism of TDD using the physical method, ‘iontophoresis’, plus the chemical method, ‘pretreatment with chemical enhancer’. The action sites of chemical enhancers in the stratum corneum (SC) were observed by electron microscope. We also studied whether this combined method synergistically impaired the skin barrier. To confirm the synergistic effect on skin penetration by this combined method, we measured the blood glucose level after insulin iontophoresis following a chemical enhancer pretreatment in rabbits. The results were that (1) dilatation of the intercellular lipid layers of the SC and lacunae was prominent in pretreatment with chemical enhancers inducing high transepidermal water loss (TEWL); (2) the skin barrier impairment, with repeated treatments showing an increased TEWL and also epidermal proliferation, was increased with the chemical enhancers that showed a high TEWL immediately after treatment; (3) the combination of chemical enhancer pretreatment and iontophoresis showed no synergistic impairment of the skin barrier, and (4) the chemical enhancer pretreatment with greater impairment of the skin barrier could increase the delivery of insulin by iontophoresis. The results showed that a combination of chemical enhancer pretreatment and iontophoresis could deliver drugs more effectively than iontophoresis alone. Our proposed theory is that iontophoretic drug delivery may be easier through the dilated intercellular spaces of the SC which have a lower electrical impedance following the chemical enhancer pretreatment. Because the effect and the side effects in the combination are decided by the chemical enhancer rather than iontophoresis, the development of proper chemical enhancers is important in future plans.

Intratumoral fat in neurofibroma.

Three cases of a solitary neurofibroma showing focal fatty changes are reported. Fatty changes in a neurofibroma are rarely observed and have not been reported, and also, the pathogenesis of neurofibroma has not been clarified. We postulate that the fatty changes in a neurofibroma may be the result of so-called senescent change or chronic injury. The origin of adipose cells may be attributable to fatty infiltration from abutting tissues or to a metaplasia of tumor cells or resident fibroblasts.

Steatocystoma multiplex localized only in the face.

A 60‐year‐old man presented with lesions on his face to the Department of Dermatology, Wonju Christian Hospital on November 10, 1994. There were over 10, slightly elevated, flat‐topped, yellowish colored, subcutaneous nodules on the face (Fig. 1). The lesions had first appeared on the left upper eyebrow at the age of 58 years, and since then they had abruptly increased in size and number and had spread into both temporal areas. Their size varied from 3 to 10 mm in diameter. No other lesions were observed on the extremities or trunk. The patients past and family history were noncontributory and the results of routine laboratory findings were within normal limits or were negative.

The effects of famciclovir and epidural block in the treatment of herpes zoster.

In our previous study, we concluded that an epidural blockade combined with intravenous acyclovir is very effective in treating the acute pain in herpes zoster and postherpetic neuralgia. We evaluated the efficacy of oral famciclovir and epidural blockade on the pain of herpes zoster, compared to acyclovir administered intravenously and epidural blockade. For this purpose, we examined a new group treated with famciclovir and epidural blockade to compare with the group treated with acyclovir and epidural blockade in our previously study. The changes in the intensity of pain, the number of days required for relief of pain, and the total duration of pain were checked. We compared the days required for relief of pain (DRP) and the total duration of pain (TDP) of this group with those of the previous studied group treated with acyclovir and epidural blockade. DRP was significantly less, but TDP was similar. DRP and TDP were significantly lower, if the patients were treated within 7 days of symptom onset. The patients had a shorter DRP regardless of pain type than the previously studied group treated with acycolvir and epidural blockade. For the severe and moderate pain grades, there was a shorter DRP from 100 to 10. TDP was not significantly different for the groups regardless of pain type or grade. We believe that famciclovir and epidural blockade are very effective in treating the pain of herpes zoster, with a view to shortening the period of acute pain, providing similar effects on the prevention of postherpetic neuralgia, and being convenient to administer, compared to intravenous acyclovir and epidural blockade in our previous study.

Functional and structural changes of the epidermal barrier induced by various types of insults in hairless mice

Abstract Acute barrier disruption, regardless of the method of induction, depletes the stratum corneum intercellular lipids and this stimulates a series of lipid/ DNA synthesis activities which lead to barrier recovery. After barrier disruption by tape stripping, occlusion with a water vapor-impermeable membrane inhibits barrier repair. In this study, we investigated the changes in the murine epidermis after barrier perturbation by tape stripping and three different types of surfactants (Emalex NP-12, ENP-12; sodium dodecyl sulfate, SDS; benzalkonium chloride, BKC). To examine the effect of an artificial barrier, we covered the animals with a water vapor-impermeable membrane for 3 days following barrier disruption and then exposed them to the air for 2 days. The histological findings after occlusion or air exposure were similar. However, after air exposure for 2 days, the thickness of the epidermis including the stratum corneum and the stratum granulosum layers decreased to about half that of the epidermis after occlusion. Ultrastructural examination revealed obvious distortion of the lamellar bilayers within the stratum corneum interstices immediately after barrier disruption. After 3 days of occlusion, extensive disorganization was evident in the intercellular domain of the stratum corneum, whereas 2 days after removal of the occlusion, the normal basic unit structure of the lamellar bilayers had partially reappeared. Our findings provide evidence that the kinetic pattern of barrier repair and the morphological changes are similar after occlusion following barrier disruption regardless of the mechanism of disruption.

Nurse's cap alopecia.

Background Traction alopecia associated with the nurse’s cap is a relatively common form of occupational hair loss.

Dermatofibroma with sclerotic areas resembling a sclerotic fibroma of the skin.

Background:  Dermatofibromas are common benign tumors that occur as single or multiple nodules on the extremities in adults. Sclerotic fibroma of the skin (SFS) is a benign tumor characterized histopathologically by a well‐demarcated, non‐encapsulated dermal nodule composed of hypocellular, sclerotic collagen bundles with prominent clefts. The pathogenesis of these two conditions is still in dispute.

Nevus spilus (speckled lentiginous nevus) associated with a nodular neurotized nevus.

We report a case of nevus spilus with neurotized nevus studied by immunohistochemical methods using S-100, leu-6, glial fibrillary acid protein (GFAP), and myelin basic protein (MBP). Histologic findings of the speckled lesion showed irregular rete ridge elongation, increased epidermal melanocytes and melanin in the epidermis, and scattered nevus cell nests in the upper dermis, but showed neurotized nevus in the deep dermis, which has many features of neurofibroma. Diffuse expression of S-100 protein and MBP, focal staining with GFAP, and lack of staining with leu-7 were observed, Leu-7, positive only in neurofibromas and not in neurotized nevus, appears to be the more pertinent method for distinguishing neurotized nevus from neurofibroma.

HETEROTOPIC SALIVARY GLANDS SIMULATING BRONCHIAL CLEFT FISTULAR IN THE LOWER NECK

A heterotopic salivary gland (HSG) in the lower neck is an unusual developmental anomaly rarely encountered by the dermatologist. Klimko and Horanyi (1) reported the first histologically documented case of HSG in the lower neck in 1958. To our knowledge, fewer than 100 such cases have been reported in the literature to date. The origin of HSG in the lower neck seems to be closely associated with the branchial apparatus. Because this condition is rarely encountered, dermatologists should be well informed about the clinical manifestations, development of various malignancies, and the differential diagnosis of HSG.

An Unusual Case with Membranous Lipodystrophy in a Hypertensive Patient with Transepidermal Elimination

Membranous lipodystrophy represents a peculiar type of fat necrosis that is present in patients with various types of skin disease. It is characterized by the presence of microcysts and macrocysts and is lined by amorphous eosinophilic material with a crenelated arabesque appearance. These findings have been associated with lupus erythematosus, diabetes mellitus, erythema nodosum, trauma, etc. We report a case of a 43-year-old woman who had a red to purple asymptomatic indurated plaque, approximately seven cm in diameter and on the left arm. She was a chronic hepatitis B antigen carrier and had hypertension for four years. Histopathology of the biopsied lesion showed transepidermal elimination of altered collagen and elastic fibers, as well as membranous lipodystrophy changes. There were hypertensive vascular changes including lymphohistiocytic infiltration around the vascular wall, swelling of endothelial cells, increased thickness of the vascular walls, and narrowing of the lumen. We report a case showing transepidermal elimination with membranous lipodystrophy. We carefully suggest that the secondary phenomenon of transepidermal elimination was associated with membranous lipodystrophy and degenerate connective tissues.