Why are Scars Pale? An Immunohistochemical Study Indicating Preservation of Melanocyte Number and Function in Surgical Scars

Shireen S. Velangi, Jonathan L. Rees
2001 Acta Dermato-Venereologica  
long-standing pale scars and gave consent for a 4 mm punch biopsy to The cosmetic eVect of many mature scars is largely due to their be taken from the scar. Eleven biopsies were taken from sun-protected paler appearance than the surrounding skin. The aim of the sites (chest 4; abdomen 5; thigh 2) and ve from sun-unprotected sites study was to identify whether melanocytes are present and (face 3; forearm 2). Subjects were skin type 2 or 3 and had not had functioning within pale scars.
more » ... e scars. Cryosections from scar and normal signi cant recent sun exposure. In addition, in 6 of these volunteers, a 4 mm punch biopsy was also taken from adjacent normal skin tissue were stained with murine monoclonal antibodies mel-5, (within 3-5 cm of the scar). Ethical approval was granted by c-kit and NKI / beteb to detect melanocytes and precursor melan-Sunderland City Hospitals Trust ethics committee. Tissue was frozen ocytes. The mean number of mel-5 immunopositive melanocytes in embedding medium (OCT; Miles, Elkhart, USA), cut into 7 mmwithin scar tissue was similar to that seen in normal skin (26, thick sections and placed on Tespa coated glass slides (Sigma-Aldrich, SEM 3.5, versus 28.9, SEM 4.1, per 200 basal cells). Where St Louis, USA) for immunohistochemical and Masson-Fontana staining. paired samples were available, there was no statistically signi cant diVerence between scar tissue and adjacent skin (95% CI = Immunohistochemistry ± 7.8 to + 4.6, p = 0.53). Masson-Fontana stain for melanin was positive in both scar tissue and adjacent normal skin, with The sections were air-dried and acetone xed at 4°C for 10 min. These no evidence for diVerences in melanin transfer to keratinocytes. speci c monoclonal antibodies were used in the 10 unpaired samples Our results suggest that neither diVerences in melanocyte number (Table I ) . Mel-5 detects a 75-kDa pigment-associated glycoprotein found on normal melanocytes and melanoma cells (4). The c-kit nor melanogenic activity explain the appearance of scars. It detects a tyrosine kinase receptor found on melanocytes and mast would seem likely that a combination of both vascular and cells; interaction between mast cell growth factor and this receptor optical factors relating to dermal or epidermal characteristics regulates the migration of melanoblasts from the neural crest and are more important.
doi:10.1080/000155501317140016 pmid:11800137 fatcat:m4qokvuha5en5mes5t4e4sfcji