Skin covers the entire body protecting us from the environment we live in. Skin is exposed daily to a variety of allergens. Skin is especially sensitive to allergens, because of the large number of mast cells and T-cells found in its tissues. Allergies of the skin are very common. Symptoms can include: swelling, hives, itching, and redness of the skin. Common skin allergies called contact dermatitis are caused by plants, such as poison ivy, poison oak and poison sumac. Also included are certain detergents, creams, and jewellery. Hives may be caused by some drugs and foods.
Acute urticaria, which may last from several hours to several days, is often allergic in origin. However, chronic urticaria, which may last weeks or even months, is rarely allergic. It may be caused by foods, food additives, medicines, but it is almost always a “pseudo-allergy”.
Urticaria may appear in several different forms, but it always includes an outbreak of pimples called “nettle rash”. This rash may appear anywhere on the body and is accompanied by pruritus (itching).
A special form of urticaria
Angioedema is a special form of urticaria. It is distin-guished by swelling on the face, particularly the lips, the eyelids (“slitty eyes”), some of the mucous membranes, and other parts of the body. There is no itching, but instead a painful or burning sensation.
Quincke’s disease, another type of urticaria, may become dangerous if it attacks the mucous membranes of the mouth and pharynx. A swollen tongue or swollen back of the mouth blocks the breathing passages, so the victim could choke or even suffocate.
There are many causes of acute urticaria:
- food allergens (eggs, fish, nuts, fruit)
- medicine allergens (penicillin, hormones, sulphonamides, etc.)
- aeroallergens (pollen, mildew, animal hair, etc.)
- insect stings (bees, wasps)
- infections (glandular fever or mono, hepatitis B. etc.)
In addition to allergic urticarias, there are some which are physical in origin: sun, cold, pressure.