Acne Age Distribution
The unequal distribution of acne amongst different age groups is a result of the high prevalence of particular clinical types of acne during certain periods of life. The adolescent clinical type of acne, for example, is associated with the hormonal changes around puberty, making it commonest in late childhood and the teenage years. Indeed, adolescent acne is so extraordinarily common compared with the other clinical types of acne that it completely dominates the age distribution profile of acne.
Acne Age Distribution Types
It is sometimes convenient to talk about age distribution types of acne - baby acne, teenage acne and adult acne - as if they were clinical entities. This type of shorthand is acceptable provided that both the user and his audience are in agreement as to what is really meant by such terms. Acne age types are not a form of clinical or diagnostic classification, but groupings based on distributional, also called epidemiological, factors. Acne age types imply nothing beyond the fact that acne is present in a patient belonging to a particular age group. The term ‘adult acne’ conveys only two pieces of information, that the patient has acne and is over the age of twenty, neither of which is particularly useful in determining the cause of the acne or in planning acne treatment. In contrast, diagnosing the clinical type of acne by examining the type and distribution of a patient's spots allows one to ascribe a cause for the acne, choose an appropriate type of acne treatment and make a prognosis.
Why are Acne Age Types Useful?
The classification of acne into different age types doesn't assist with the identification of the causes of acne in individual patients. Acne age types are useful for identifying patients whose acne does not fit the 'normal pattern' However, acne age types are useful for identifying patients whose acne does not fit the 'normal pattern' and in whom there may be a rare, perhaps serious, underlying cause of the acne. To illustrate the point, a doctor will react entirely differently on seeing a 6 year old with acne as opposed to a 16 year old with acne. Acne in a teenager is a normal pattern of presentation. The doctor will want to confirm by examining the teenager's spots that the acne is of the adolescent clinical type, discuss treatment and move on to the next patient. In contrast, acne in a 6 year old will set the doctor's alarm bells ringing. Acne is rare in childhood and particularly so prior to the age of 8 or 9, the pre-teen period when children may be approaching or entering puberty. Acne in a 6 year old may be a form of drug-induced acne or may be adolescent acne associated with precocious puberty, caused by an underlying endocrine disorder or tumour. In such a case, it is the development of acne in an age group in which acne is rare which has alerted the doctor to the seriousness of the situation and, in all probability, the need for referral to a specialist.
How Common is Common?
Doctors talk about conditions being common in some age groups, rare in others, without ever explaining what common or rare mean in a medical context. Part of the problem is that the terms carry different meanings for different medical specialists. To an oncologist, a doctor specialising in cancer, a tumour with an incidence of 1 in 10,000 per annum might be considered common, one with an incidence of 1 in 1,000,000 being considered rare. On average, a General Practitioner would see a case of the tumour with an incidence of 1 in 10,000 every 5 years and would probably consider it a rare condition. The use of the terms ‘common’ and ‘rare’ by General Practitioners comes closest to their non-medical usage, since GPs see a cross section of medical conditions which patients view as being worthy of medical attention. General Practitioners class conditions such as 'flu, asthma, diabetes and high blood pressure as common. The overall incidence of acne across the whole population is high enough for it to be classed as a common condition, but there is such a huge disparity between the different age groups that it is much more meaningful to talk in terms of how common acne is in different age groups. The remainder of the section considers the distribution of acne across five different age groups - babies, children, pre-teens, teenagers and adults - and explains what it means in practical terms to describe teenage acne as ‘extraordinarily’ common and childhood acne as ‘rare’.
