Allergies And Skin Problems by Jane Thurnell-Read

Allergies can really affect the skin. Here are some suggestions about how allergies link to skin complaints such as eczema, hives and less common problems.

Angioedema

This is similar to urticaria, but affects the body at the level of the blood vessels, causing swelling from excess fluid. Often caused by a sudden reaction to seafood, peanuts, strawberries or eggs. Common sites are the skin, the gastro-intestinal tract and the throat and larynx. This can be very dangerous causing difficulty in breathing, speaking and swallowing. During an attack emergency medical treatment is likely to be needed. Often involved in anaphylactic shock. Common culprits are bee sting, penicillin, aspirin, food colourings and preservatives, shellfish, strawberries, nuts and peanuts.

Dermatitis

In dermatitis the skin becomes inflamed and will be sore and possibly itchy. Contact dermatitis occurs when the skin reacts to something it is in contact with, such as nickel, chromium, perfume, some plants and latex. Sometimes the dermatitis appears in a sensitive area of the skin rather than the actual site of the initial contact. For example, a nail polish allergy may not show up on the robust skin around the nail, but could affect the more sensitive skin around the eyes, because it has been touched by the varnished nail. Can also be caused by reactions to commonly consumed foods.

Dermatitis Herpetiformis

In families where coeliac disease is common some members may experience this reaction to gluten. Symptoms include a chronic, symmetrical, itchy rash. Common areas are the back, buttocks, elbows, knees and scalp.

Dermatographism

Some allergy sufferers have a skin that is highly sensitive and reactive and will develop a red line or an itchy weal if the skin is firmly stroked. It is a form of urticaria.

Eczema

Common eczema culprits are cow’s milk, house dust mite, detergents, perfumes, man-made fibres (such as polyester and acrylic), lanolin, nickel and pet hair. Can be triggered by airborne allergens in some people. This may be because some of the airborne particles are swallowed rather than inhaled.

Sometimes people will show eczema in different places depending on what they have been exposed to. For example, my eldest son used to get eczema in the flexures of his legs and arms whenever he ate wheat, but if he ate something with the food colouring tartrazine in it he would get a small patch of eczema in one specific place on his back, whereas another food colouring would make him itch at a different spot on his back. As far as I know this is an individual thing, so wheat or these food colourings could cause someone else to itch in a different place. This may explain why sometimes eczema is successfully cleared from some places on the body, but not from others – the allergen(s) that apply to only some areas have been successfully dealt with.

Sometimes eczema appears in a particular area because of direct contact with an allergen. A client whose eczema was so severe he had been hospitalised on several occasions told me that the only time the eczema on his legs cleared was when he went into hospital. I found he was allergic to the indigo dye in the jeans he always wore, which suggested that it was not the hospital treatment itself, but simply that in hospital he wore pyjamas all day rather than jeans.

As an added complication, fungal and bacterial infections can colonise the skin legions in eczema, causing further irritation. When this is the case, removing the allergens that started the eczema will not be sufficient to allow the skin to settle down. The micro-organisms involved are usually Staphylococcus aureus, Candida or Trichophyton.
If fungal infection of the eczema is a problem, there will usually be scarring or the skin will look silvery as it heals.

Eczema sufferers will sometimes also react to Pityrosporum ovale. This is a yeast that is normally present on the surface of the skin.

Hives

See urticaria below.

Skin Rashes

Skin rashes can be caused by a wide variety of allergens, including chemicals, nickel and drugs, particularly antibiotics.

Urticaria

Urticaria is also called hives or nettle rash. A condition characterised by an itchy rash consisting of white or yellow lumps surrounded by an area of red inflammation. Common culprits are food additives, chemicals, nickel, and drugs. Some unfortunate people develop urticaria in reaction to sunlight. Chronic urticaria has been linked to chronic trichophyton diseases such as athlete’s foot, and chronic sinusitis or throat infections. The body is producing IgE antibodies in an attempt to fight the athlete’s foot; the antibodies are carried in the blood stream and symptoms of urticaria may appear elsewhere.

Copyright 2008 Jane Thurnell-Read, author of Allergy A To Z