Nail Anatomy & Pathology Flashcards

What is paronychia?

Answer: Infection and inflammation of the tissue surrounding the nail (nail fold)

Paronychia is an infection of the skin around the nail (periungual tissue), presenting as redness, swelling, pain, and sometimes pus. It can be acute (bacterial) or chronic (often candidal).

What are Beau's lines?

Answer: Transverse depressions across the nail plate caused by temporary disruption of nail matrix growth

Beau's lines are horizontal grooves or depressions in the nail plate resulting from temporary cessation of nail matrix activity, often caused by severe illness, trauma, or chemotherapy.

What systemic condition can cause spoon-shaped nails (koilonychia)?

Answer: Iron deficiency anemia

Koilonychia (spoon nails) features concave, upwardly curved nail plates. While it can be normal in infants, in adults it is often associated with iron deficiency anemia, hemochromatosis, or thyroid disorders.

What is the nail plate composed of?

Answer: Hard keratinized protein layers produced by the nail matrix

The nail plate is made of tightly packed layers of translucent keratin protein (alpha-keratin), the same protein found in hair. Despite common belief, calcium plays a minimal role in nail hardness.

What are splinter hemorrhages under the nail?

Answer: Thin, dark red-brown lines under the nail caused by tiny blood vessel damage in the nail bed

Splinter hemorrhages are longitudinal thin lines of blood under the nail, caused by damage to small capillaries in the nail bed. While often from trauma, they can indicate endocarditis or vasculitis.

What is pterygium of the nail?

Answer: Abnormal growth of skin tissue (cuticle or proximal nail fold) that adheres to and grows over the nail plate

Nail pterygium involves the forward growth of the proximal nail fold over the nail plate, often seen in lichen planus or severe trauma. It can cause permanent nail destruction if not treated.