Periodic acid Schiff-stained, 4-μm histologic section of skin from a lowland leopard frog (Rana yavapaiensis) infected with the chytrid fungus Batrachochytrium dendrobatidis. B. dendrobatidis (arrows) has colonized the superficial epidermal layer of frog skin. Physiological response to fungal infection includes thickening of the keratin layer (most lost in processing) and increased cells in the epidermis (cells between arrows and arrow heads), but there is no inflammation.
Cryan et al. BMC Biology 2010 8:135 doi:10.1186/1741-7007-8-135