Medical term

Explanation

Apoptosis

A process of programmed cell death by which cells undergo an ordered sequence of events which lead to the death of the cell. This occurs during growth and development of the organism as a part of normal cell aging or as a response to cellular injury

Collagenase

An enzyme which breaks the peptide bonds in collagen

Cytokines

Small protein molecules that are secreted by cells of the nervous system or the immune system. They are used in intercellular communication

Defective maturation of epidermal keratinocytes

Incomplete formation of keratin (the horny material in nails) due to rapid growth of cells in the epidermal layer of the skin

Dilatation of dermal capillaries

Dilation of small blood vessels in the skin

Erythrodermic psoriasis

A subtype of psoriasis that affects all body sites

Erythrogenic response

Redness of the skin caused by light exposure

Extensor aspects

An anatomical term ‐ when a joint bends, the parts of the skin on the opposite side of the joint are called the extensor aspects

Hyperkeratosis

Thickening of the stratum corneum (outermost layer of the skin) usually associated with an abnormality of the keratin and an increase of the granular layer of the skin

Hyperplasia

An increase in the number of cells

Hyperproliferation

An abnormally high rate of proliferation of cells by rapid division

Pustular

Lesions containing purulent materials

Photosensitiser

Chemical treatments that are used to sensitise the skin and enhance the effect of light treatments