The epidermis, the outer skin layer, is organized into a stratified sequence of keratinocyte layers (stratum basale, spinosum, granulosum, lucidum, corneum) reflecting a maturation gradient from proliferating basal cells to dead outer cells; adjacent keratinocytes are joined by desmosomes, while the epidermis attaches to the underlying dermis via hemidesmosomes at the basement membrane. The anatomical level at which an immune-mediated blistering process disrupts these junctions (intraepidermal, between keratinocytes, versus at the dermal-epidermal junction) determines the structural integrity and tension of the resulting bulla, providing a mechanistic basis for localizing autoimmune skin disease within dermatologic pathophysiology.
The epidermis, the outer skin layer, is organized into a stratified sequence of keratinocyte layers (stratum basale, spinosum, granulosum, lucidum, corneum) reflecting a maturation gradient from prol…