Character of the tongue: The fungiform papillae are enlarged and protrude to form spikes like awn, which can be touched.
Clinical significance: It indicates blood heat or excess heat in the internal organs. The color or the prickles can help estimate the flow of qi and blood. The bright red prickles indicate blood heat, the crimson ones indicates extreme heat, and the white ones indicate edema.
Also see Relationship Between Blood and Body Fluid.