In the bedroom, let’s head for the wardrobe full of clean, fresh-smelling clothes, courtesy of that tub of biological washing powder. This type of laundry detergent contains quantities of enzymes (proteases and lipases) that digest proteins and fats - for exceptional stain-removing even at low temperatures. But traces of these enzymes stay in the fabric and, when it comes in contact with the skin, can trigger eczematous reactions.
Switching to a non-biological washing powder may help, but those also contain irritants such as preservatives, to protect fabric against the effects of ageing, as well as synthetic fragrances, to give laundry that smell of ‘summer freshness’.
The type of fabric is also important in controlling skin inflammation. Eczema sufferers are often told to steer clear of wool, an irritant even for those with normal skin sensitivity. But synthetic fibres also provoke or aggravate eczema. One study found that three synthetic shirts had a significantly greater capacity to irritate eczema patients, while a cotton shirt was the best tolerated (Z Hautkr, 1990; 65: 907-10).
What about that genuine leather jacket with the matching leather shoes you got for Christmas? They’re made from a natural material and so should get a thumbs-up, right? Wrong – though it’s not the leather that poses the problem, but the chemical used to treat it - namely, chromates, the chromium compounds used for tanning (Contact Dermatitis, 1996; 35: 83-5). Try substituting your leather items for those that have been vegetable-tanned instead. And when you’re buying a new pair of shoes, it may be worth remembering that manufactured rubber shoe soles contain two common eczema allergens, thiuram and mercaptobenzothiazole (Allerg Immunol [Leipz], 1974-75; 20-21: 281-5).
Your jewellery box may also harbour allergens, especially if it contains nickel jewellery. Eczema on the ears is a familiar sight thanks to nickel-containing earrings. The metal is also used for belt buckles, zippers, buttons and snaps. Nickel-related eczema may be worsened by sweat as the moisture allows the metal ions to be better absorbed into the skin.
Less obvious sources of allergy are stainless-steel or chromium-cobalt products. Through chronic exposure from, for example, metallic orthopaedic implants, enough toxic metal can leach into the system and provoke an allergic eczema response (Rev Chir Orthop Reparatr Appar Mot, 1995; 81: 473-84).
This list of allergens and toxins, cleverly concealed in every corner of your home, is far from exhaustive. Our daily exposure to them has fuelled the rising numbers of eczema cases, and only by removing them can we control this epidemic.