Epidemiology of skin disease
Skin disease is very common. About 10% of a general practitioner’s workload and 6% of hospital outpatient referrals can be accounted for by skin problems. Skin disease is also economically significant; it is a major occupational cause of loss of time from work and the third most common industrial disease (p. 124).
In any discussion of epidemiology, it is important first to define the terms used:
Prevalence refers to the proportion of a defined population affected by a disease at any given time.
Skin disease in the general population
Reliable population statistics are difficult to obtain, but it appears that, in Europe, the prevalence of skin disease needing some sort of medical care is about 20%. Eczema, acne and infective disorders (including warts) are the commonest complaints (Fig. 1). Only a minority seek medical advice.
Skin disease in community and specialized clinics
The precise proportion of skin disorders seen in a community setting (Fig. 2) will vary with the age structure of the population served, the amount and type of industry in the area and socioeconomic factors. Demographic studies may reveal a trend; for example, for unknown reasons, atopic eczema has become more common over the last 30 years.
Patients seen in a specialist dermatology clinic are a selected population (Fig. 3). In some countries, e.g. the UK, a general practitioner will have referred them; in other places, self-referral may depend on the availability of medical insurance. Referral patterns vary between different regions, depending on local facilities, interests and customs. In Europe, within a year, just over 1% of the population is referred for a dermatological opinion. In the early 2010s, a quarter of all new referrals required a surgical procedure.
