Histologic Changes in Seborrheic Keratoses After Rubbing

The study examined histologic changes in seborrheic keratoses after rubbing in 5 patients. Initial changes included hemorrhage, hyalinization of dermal papillae, and necrosis of epithelial tips. After 48 hours, changes such as loss of epithelial mass, expansion of keratin cysts, thinning of the epithelium, and proliferation of epithelial strands were observed. There was also an increase in epithelial cell size and evidence of hair follicle relationships, including trichostasis spinulosa and hair germ proliferation in one specimen. Dermal lymphocytic infiltration varied and rarely involved the epithelium. The findings suggested a patterned response to trauma and a link between seborrheic keratosis and hair follicles.