ABSTRACT
Botulinum toxin (BTX)-A has been used for years in the reduction of facial wrinkles; however, histological and immunohistochemical changes after its use were not previously investigated. To evaluate histological and immunohistochemical changes after BTX-A injection for facial wrinkles, sixteen volunteers, with wrinkles on the upper third of the face, were subjected to single injection of BTX-A. Skin biopsy specimens were obtained from peri-orbital wrinkle site (crow's feet area) before and after 3 months of BTX-A injection. Using histological and immunohistochemical evaluation coupled with computerized morphometric analysis, measurement of epidermal thickness, wrinkle depth and width as well as quantitative evaluation of collagen types I and III and elastin was performed for skin biopsies. After BTX-A injections, there were significant increase in wrinkle width and granular layer thickness (P < 0.001), while the other histometrical measures as well as the immunohistochemical expression of collagen types I and III and elastin showed no significant difference (P > 0.05). However, collagen fibers showed better organization and orientation after BTX-A injection. The histological changes observed after BTX-A injection for facial wrinkles may help in better understanding of its mechanism of action.
Subject(s)
Botulinum Toxins, Type A/administration & dosage , Neuromuscular Agents/administration & dosage , Skin Aging/drug effects , Skin/metabolism , Skin/pathology , Adult , Biopsy , Collagen Type I/metabolism , Collagen Type III/metabolism , Elastin/metabolism , Epidermis/metabolism , Epidermis/pathology , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , Skin Aging/pathology , Skin Aging/physiologyABSTRACT
BACKGROUND AND AIMS: Psoralen ultraviolet A (PUVA) is an important modality in treating vitiligo. Its effect on melanocytes and keratinocytes is not sufficiently studied. In this work, we investigated 30 cases of non-segmental vitiligo regarding the changes of melanocytes and keratinocytes in both vitiliginous and nearby areas before and after PUVA therapy. METHODS: Three skin biopsies were obtained from each patient from the vitiliginous, marginal and perilesional areas before and after 12 months of PUVA. Biopsies were examined histologically using haematoxylin and eosin, Masson-Fontana stains and 3,4-dihydroxyphenylalanine (DOPA) reaction and histochemically using human melanoma black-45 (HMB-45) antibody while ultrastructural examination was performed on six patients. Control biopsies were taken from five healthy volunteers. RESULTS: In 10% of pretreated biopsies from the centre of vitiligo lesions, scanty melanocytes were detected histologically and ultrastructurally, while they did not stain with DOPA or HMB-45 antibody suggesting that these melanocytes were inactive. Moreover, degenerative changes were detected by electron microscopy in both melanocytes and keratinocytes in all areas. After PUVA therapy, obvious improvement of the histopathological changes occurred with significant increase in active melanocytes. The degeneration of melanocytes and keratinocytes was also reduced at the ultrastructural level. CONCLUSION: Vitiligo affects both melanocytes and keratinocytes causing degenerative changes. These changes were present in both the leucodermic and the apparently normal perilesional skin. PUVA increases the number of active epidermal melanocytes in the three tested areas and recovers the melanocyte and keratinocyte degeneration.
Subject(s)
Epidermis/ultrastructure , Keratinocytes/ultrastructure , Melanocytes/ultrastructure , PUVA Therapy/adverse effects , Vitiligo/drug therapy , Vitiligo/pathology , Adolescent , Adult , Biopsy , Epidermis/metabolism , Female , Humans , Keratinocytes/metabolism , Male , Melanocytes/metabolism , Middle Aged , PUVA Therapy/methods , Vitiligo/metabolismABSTRACT
It has been observed that depigmentation in vitiligo passes through two stages; patches of light brown hypopigmentation which gradually changes into milky white patches. In this work, we studied two cases of hypopigmented vitiligo regarding the melanocytes and keratinocytes' changes before and after 7 months of psoralen plus ultraviolet A (PUVA) therapy. Skin biopsies were taken from the vitiliginous lesions before and after 7 months of PUVA therapy and were examined using haematoxylin and eosin and Masson Fontana stains, L-3,4-dihydroxyphenylalanine reaction, immuno-histochemical stains and ultrastructural examination. In the pretreated patients, the melanocytes present were inactive and degenerative changes were detected in both melanocytes and keratinocytes. After PUVA therapy, obvious histopathological improvement was detected. Clinically, the initial response to PUVA therapy was increased hypopigmentation indicating that degenerated cells in the vitiliginous patches might have continued the process of degeneration and did not recover. Meanwhile, the perifollicular and marginal pigmentation suggested that pigmentation occurred from those areas and not from activation of already degenerated melanocytes.
