General Dermatology Definitions

Question 1

Acanthocyte

Answer 1

Epidermal cell free in a vesicle/pustule, caused by acantholysis

Question 2

Acantholysis

Answer 2

Loss of cohesion between cells of the living epidermis

Question 3

Acanthosis

Answer 3

Hyperplasia of stratum spinosum

Question 4

Apoptosis

Answer 4

Individual cell death, requiring energy

Question 5

Dyskeratosis

Answer 5

Abnormal, premature or imperfect keratinisation of keratinocytes

Question 6

Epidermolysis

Answer 6

Degeneration of epidermal basal layer -> separation of epidermis from dermis

Question 7

Exocytosis

Answer 7

Migration of inflammatory cells from dermis -> epidermis

Question 8

Hydropic degeneration

Answer 8

Vacuoles in stratum basale -> intrabasal or subepidermal clefts

Question 9

Hyperkeratosis

Answer 9

Increase in stratum corneum (orthokeratotic/parakeratotic; basket-weave/compact)

Question 10

Intracellular oedema

Answer 10

Occurs with hydropic degeneration of basal cells and ballooning degeneration (seen with herpes virus infections)

Question 11

Necrolysis

Answer 11

Epidermal necrosis with no dermal involvement and minimal inflammation

Question 12

Orthokeratosis

Answer 12

Excessive cornification – keratinocytes lose nuclei

Question 13

Parakeratosis

Answer 13

Excessive cornification – keratinocytes retain nuclei

Question 14

Pigment incontinence

Answer 14

Release of melanin granules into superficial dermis