In yet another study in Oxford, vaccination with whole cell pertussis vaccine was significantly associated with development of atopic disorders (Thorax, 1998; 53: 927-32). This study also found

a significant relationship between childhood antibiotic use and the development of atopy (see below).

However, a new Finnish study one of the largest ever conducted suggests that early exposure to what the researchers called 'natural measles' was not protective against atopy (Lancet, 2000; 283: 343-6).

A closer look at the data, however, reveals an interesting definition of 'natural measles'. The study was based on data from 547,910 children, aged 14 months to 19 years at the time of a mass MMR vaccination campaign (1982-1986) in Finland. Data on atopic conditions was collected at the time of the campaign and showed that while 20,690 children reported having measles, 52,087 reported having eczema, 17,131 had allergic rhinitis and another 10,058 had asthma.

However, it was older children (aged 8 and up) who were most likely to have reported measles before the vaccination children who may have been on the receiving end of the single measles vaccine, which was the standard from 1975 to 1982 and given to as many as 70 per cent of Finnish children.

The authors did not disclose information on previous vaccination history but, among such children, measles infection is anything but natural. It may be caused by mutations of the disease due to the vaccine or, equally, it may be such a mild disease that it does not fully 'challenge' or develop the immune system.

Commenting on the study (Lancet, 2000; 283: 394-5), Drs James E. Gern, University of Wisconsin Medical School, and Scott T. Weiss, Harvard Medical School, suggest that while the study was large, its parameters were too narrow to be conclusive ,and that it was probably exposure to infectious diseases in general particularly lower respiratory tract infections and not just to measles that is protective against atopy. Say the authors, "Measles infection is not a good indicator of overall exposure to infectious disease in a Western environment such as Finland." They also note that other factors, such as the timing of infection, may also be relevant.

Germ phobia

High uptake of childhood vaccinations, of course, mirrors an increasing decline in breastfeeding, found to protect against many childhood disorders such as eczema as well as colds and other infections. It's an important point since a non breastfed child is more likely to succumb to such diseases and, in our germphobic culture, more likely to be given medications such as antibiotics and NSAIDs to 'fight' the bug and its symptoms.

Both antibiotics and NSAIDs such as paracetamol (a prime ingredient in many infant suspensions) are also associated with the development of eczema.

Antibiotics, of course, are sometimes given in combination with steroids as standard therapy for eczema. The rationale behind this is that the open sores common to eczema may become infected. However, continual use of antibiotics can cause Candida overgrowth which can actually make the eczema worse.

Antibiotics taken for other reasons may be similarly damaging. In a study in Belgium, data were collected from 1206 six and seven year old children who were not exposed to antibiotics in the first year of life, and 675 children who were. The use of antibiotics early in life was found to be significantly associated with atopy in children who had a family history of the disorder (Clin Exp Allergy, 2000; 30: 1548-53).