What price beauty? Onwards now to the bathroom where, scattered around the bathtub, we are likely to find a colourful abundance of bubble bath, shower gels and shampoos, each pledging to leave you squeaky clean and healthy.

Nevertheless, these products contain a cocktail of chemicals that threaten your health. You wouldn’t dream of soaking yourself in a tub of washing-up liquid, but look more closely at your bottle of bubble bath and you’ll find, lurking among the list of ingredients, SLS - that aggressive cleaning agent and common cause of eczema. Other bathroom hiding places of SLS are toothpastes, shampoos, shower gels and just about every personal-cleaning solution.

Most facial washes designed to keep your skin clear of unsightly spots use polyethylene glycol (PEG), a caustic that dissolves grease - whether on your person or in the oven. But it’s also a recognised toxin that can cause an immediate or delayed allergic eczema reaction (Contact Dermatitis, 1978; 4: 135-8).

A relative of PEG, propylene glycol (PG) is a solvent used by manufacturers for its moisture-regulating, antiseptic and preservative effects. Commonly used in cosmetics, haircare products, deodorants and aftershave, it’s also a main ingredient in antifreeze and brake fluid. PG is believed to be more irritant than allergen, and most skin reactions to the chemical tend to be due to its toxicity, rather than an allergic response (Contact Dermatitis, 1975; 1: 112-6; Hautarzt, 1982; 33: 12-4).

An allergen commonly found in cosmetics and toiletries is lanolin. To be more precise, it’s the wool alcohols in refined lanolin that are often responsible for eczematous flare-ups. A natural product derived from fleece, lanolin’s high fat content makes it a good moisturising base for products such as hand creams, skin moisturisers, glossy lipsticks, cream makeup foundation and bath oils. Ironically, it is used in some emollients to treat dry skin conditions such as mild eczema. Lanolin is also ubiquitous in hairsprays, air fresheners, household-cleaning products, laundry detergents, treated fabrics (for a waterproof finish) and clothes dye.

And what’s a bubble bath if it doesn’t exude the soothing aroma of ylang ylang or lavender? Fragrance has become a major selling point for many personal-hygiene products and cosmetics. But the cost of sweet-smelling skin is high, taking into account the more than 5000 chemicals used in fragrance manufacture - many of which are known toxins and allergens.

And if you’ve been using a favourite fragrance for some time now, you may want to consider drastically cutting down on that spritzing. Researchers have found a positive correlation between age and fragrance allergy. It appears that repeated exposure to fragrance and age-related susceptibility factors, such as increased skin permeability, both contribute to the increase in the number of fragrance-allergy sufferers (Br J Dermatol, 2003; 149: 986-9).

Other allergens and toxins that you submit yourself to in the name of beauty include:

* formaldehyde, commonly used as a preservative in cosmetics, as well as in cleaning agents and industrial products (Am J Contact Dermat, 1999; 10: 12-7)

* paraphenylenedeamine (PPDA) and related agents, found in permanent hair dyes and a common cause of occupational eczema among hairdressers (Contact Dermatitis, 2002; 46: 319- 24). Even home hair-dyeing kits, which mostly use semipermanent dyes, penetrate the shaft of the hair, allowing chemicals to enter the skin and cause an allergic reaction. Switch to temporary or vegetable (henna) dyes instead.