Skin Conditions Glossary

Here is a list of descriptions of medical terminology used in this guide.



This is a very common skin condition which affects mainly teenage boys. It is caused by the overproduction of sebum (oil) from sebaceous glands within the skin which blocks the pores, resulting in a rash and inflamed skin. This is characterised by pimples, blackheads, cysts and whiteheads.


This is a hypersensitive reaction by the immune system to a substance, food, object or chemical which causes a skin rash and other symptoms. An example of this is eczema.


These are proteins released by the immune system to attack a foreign invader, e.g. bacteria or virus.


Basal cell

This is a type of skin cell which is found in the deep layers of skin.


This is the opposite of cancerous: not harmful to the health


This is a skin blemish which appears at birth, e.g. port wine stain.



This is a type of abscess (filled with pus) which is red, sore and painful and caused by bacteria.

Cold sores

This is also known as Herpes Simplex: these are small blister like swellings which develop on or around the mouth.


This is a small sac like growth underneath the skin which may ooze fluid onto the skin.



This is a common skin complaint which causes redness, itching and inflammation of the skin from touching an irritating substance or as an allergic reaction. There are two types of dermatitis: allergic contact dermatitis and irritant contact dermatitis.

Dry skin

This develops when the skin becomes stripped of its natural oils, leading to a tight sensation, swelling and cracks in the surface.



This is a very common skin condition which is caused by a variety of reasons, some unknown, resulting in dry, red, itchy skin which may crack and bleed.


Family history

This is what a GP or dermatologist will ask about during the initial consultation: they will ask about the types of diseases and illnesses prevalent in your family to see if there is a genetic link.



This refers to an organ within the body that produces a substance for use within the body. An example of this is the thyroid gland which releases hormones that regulate the metabolism.



Substances produced by the body that control the activities of different organs or cells.



This is a physical reaction by the body’s immune system which causes redness, heat, pain and swelling in a particular area of the body, e.g. the skin.


A common feature of many skin conditions in which the sufferer experiences a crawling sensation on their skin. This causes a strong desire to scratch or rub the affected area.


None at present.



This is a structural protein found within the nails, hair and skin.



The full name is discoid lupus erythematosus: this is a chronic skin disease which presents as scaly lesions, pain and inflammation on the face and body. These lesions are similar in appearance to warts and may cause scarring. This disease affects the internal organs in a small percentage of sufferers.



The full name is malignant melanoma: a potentially fatal form of skin cancer caused by a cancerous mole which spreads to other parts of the body.


A small flat round spot on the skin which vary in colour from pink through to dark brown. Some people have more moles than others. They are for the large part harmless although a small percentage of these can become cancerous. Need to be checked on a regular basis.



This is a small lump of tissue which forms in any of the layers of the skin. A common feature of acne.



This is an autoimmune disorder which causes large red, scaly patches to appear on the skin. These patches have a silvery covering and develop on the elbows, knees, scalp and chest of the sufferer.



This is a medical term used to describe a change in the colour, texture or appearance of the skin: a localised outbreak, e.g. spots or pimples on the skin. A rash is accompanied by itching and other symptoms, e.g. fever and chills.



This is an autoimmune disorder which causes thickening of the skin and in some cases, the internal organs.

Solar keratosis

Small scaly skin growths which are pre-cancerous and caused by prolonged sun exposure.

Sun protection factor (SPF)

A rating system used by suncream manufacturers which determines the ability of the product to block out the sun’s rays. A higher SPF, e.g. +15 means a greater level of protection against the sun.


Thyroid gland

The butterfly shaped gland within the neck which forms part of the body’s endocrine system. This gland releases hormones into the bloodstream which control growth and the metabolism.



This is also known as hives: a type of skin condition characterised by small itchy red bumps on the skin which develop as a reaction to something, e.g. shellfish.


Vitamin A

Known as retinol: an essential vitamin needed for healthy skin, teeth, bones and eyes. It helps protect the body against disease and infection.



This is a small hard, scaly lump which develops on the hands, feet, wrists or neck but can develop on any part of the body. These are benign growths which often clear up without need for treatment.



Skin which is abnormally dry caused by a Vitamin A deficiency or an underactive thyroid gland.


Yeast infection

An infection caused by a naturally occurring fungus within the skin. This causes an overproduction of yeast which results in the development of itchy white patches on the skin that are painful and inflamed.


None at present.