While nickel allergy often produces wet pustules, nickel intolerance causes a delayed form of eczema with dry blistering, which is, curiously enough, usually limited to the hands. For me, the first signs are deep-red patches in the palms of the hand and along the sides of the fingers. The inflammation develops right underneath the skin, causing it to harden and thereby to tighten. Eventually, the skin will blister and break. Underneath, there is new healthy skin, but during the transition from old to new skin, the skin tends to be rough and scaly. Unfortunately, sometimes a new outbreak starts while the skin still healing from the last one.
Ramona’s tip: Use petroleum jelly and use it frequently! I have tried many skin creams, but none has been as effective in smoothing the skin during an outbreak.
Having a nickel allergy is not uncommon nowadays, which is why we see so many items labelled “nickel free.” Not so well-known is the fact that you can also have an adverse reaction to nickel in food in form of a non-allergic food hypersensitivity, also known less precisely as food intolerance. If you have a nickel allergy, it means that direct contact with nickel causes a skin reaction, which either manifests itself immediately or quickly after contact. This is called an allergic contact dermatitis. Hypersensitivity to nickel in food is not a food allergy like, for example, a nut allergy. A food allergy is caused when the body misidentifies a certain food item as harmful and launches a fast-acting immune mechanism in the body, usually by releasing high amounts of antibodies. The reaction is more or less immediate and can, in extreme cases, lead to an anaphylactic shock. Nickel in food is not life-threatening, but it poses some severe restrictions on your diet. The symptoms often take a while until they manifest themselves, so that identifying a particular food item as the cause for the reaction can be quite difficult. Although the body requires nickel, just as it needs iron and zinc, it only requires minute amounts. If you are intolerant to nickel in food, it means that the body is unable to deal with any excess in your body. You are passing a threshold of tolerance and suddenly what is considered healthy becomes the cause of eczema.
For general information on food allergies and intolerances, check this site: http://www.foodallergens.info/Facts/Symptoms.html