papilla vs pustule

papilla

noun
  • Any of the vascular protuberances of the dermal layer of the skin extending into the epidermal layer and often containing tactile corpuscles. 

  • Any of the small protuberances on the upper surface of the tongue often containing taste buds. 

  • A vascular process of connective tissue extending into and nourishing the root of a hair, feather, or developing tooth. 

  • A small fleshy projection on a plant. 

pustule

noun
  • A small accumulation of pus in the epidermis or dermis. 

  • Anything like a pustule, on plants or animals; a small blister. 

  • A pimple filled with pus. 

How often have the words papilla and pustule occurred in a corpus of books? (source: Google Ngram Viewer )