Types of Acne Spots
What characterises acne, and distinguishes it from other skin disorders, is the appearance on the skin of affected parts of the body of spots of one or more particular types. The four characteristic types of spots which may develop in acne are:
- Papules
A Papule is a small raised area of skin (a spot) and is the correct medical term for what most people refer to simply as a pimple. The surface of the skin forming a papule remains unbroken and the skin may or may not be discoloured. - Whiteheads
A whitehead, known medically as a closed comedo, is a raised area of skin (a spot) with a distinctive white centre. The skin covering a whitehead is not broken, but there will usually be a ring of red, inflamed skin surrounding the white centre of the spot. - Blackheads
A blackhead, known medically as an open comedo, is a raised area of skin (a spot) which has a pigmented centre which appears dark brown or black in colour. The discoloration is visible through an area of broken skin at the centre of the spot, around which the skin will appear red and inflamed. - Pustules
A pustule is a raised area of skin (a spot) which contains a visible accumulation of free pus. The pus appears a creamy yellow colour when seen through the translucent surface of the skin. The pustule may 'burst' to discharge the free pus onto the skins surface either as a natural process or as a result of the spot being squeezed, or the pustule may resolve without bursting.
Differentiation of Acne Spots
It is important to understand that although each type of acne spot has a different appearance, all the spots are produced by essentially the same process. Some combination of seborrhoea, the failure of dead skins cells to be cleared effectively from the hair follicle and the action of the Propionibacterium acnes results in the formation of a comedo within the pilo-sebaceous unit. Subsequent inflammatory action within and around the comedo causes the formation of a visible acne spot. It is the extent of the inflammation, the amount of damage it causes to surrounding tissue and the presence or absence of active infection which will determine the type of spot which will appear initially and how that spot might develop.
Coexistence of Acne Spots
In the mildest form of acne, one typically finds only a smattering of papules which gradually appear and then disappear over time. Such papules do not develop into anything more sinister and resolve to leaving no trace of their presence. It is however much more common to find acne spots of more than one type coexisting in the same patient. In the severe form of acne the skin may be so densely covered with a seething mass of spots that the individual spots appear to coalesce to form large areas of active inflammation. Look closely though and you'll probably be able to identify examples of all the characteristic types of spots found in acne, papules, pustules, whiteheads and blackheads, some of which will be in the process of healing as other are just emerging.
Acne Cysts
You may also come across spots beneath which the skin has formed into a dome-shaped swelling, which is typically 1-2cm across, appears angry red in colour and is firm to the touch, but often tender. These nodular swellings are a sign of the development of acne cysts, which are large and deep seated areas of intense inflammatory activity. Cystic acne is an serious complication of acne since it almost invariably heals to leave permanent acne scars.
