What is Urticaria?
Nettle-rash or Hives also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. They may also burn or sting. Often the patches of rash move around.
Urticaria is an allergic or non-allergic immunological disease, shown on the skin. Characteristically the skin eruptions are erythematous, raised above the skin level, with intense itching and usually worsened by itching an with slight local warmth. It can be acute or chronic; largely having a tendency to recur frequently for many months or years.
These eruptions can remain on the body for variable period anywhere between few seconds to even hours. They have tendency to disappear and reappear. They tend to disappear without leaving behind any trace.
Location and duration:
Well, urticaria may appear on any part of the skin. Angioedema is a condition when deep tissues are affected. The typical lesions may last for one minute to half an hour. Some may last even longer. Some patients may get the eruptions once in a while and some may have many times during the day. It may be restricted to a couple of spots in some patients, while some may have wide spread rashes appearing for days or even months together.
There are acute, sub-acute, chronic and recurring variants as far as the frequency and duration are concerned.
Under the microscope, a typical urticarial rash may exhibit perivascular, cellular infiltrate consisting of lymphocytes and eosinophils, is indicative of it’s allergic behavior. There are findings related to edema (swelling) and mucosal inflammation.
Urticaria: The Inner War
The urticaria rash is a symptom of an allergic and immunological event taking place at the dermal level. The exact understanding is illusive to an extent. In brief, urticaria is a hypersensitive reaction due to the histamine release. The histamine release could be from the mast cells when antigens and antibodies (IgM or IgG) combine to activate the immunological reaction. The histamine release could IgE induced. There are certain drugs, pharmacological agents (e.g.: antibiotics, morphine, aspirin, etc.), food articles (proteins, milk products, etc.) Urticaria is a sign of antigen-antibody reaction. During this process of antibody-antigen reaction, histamine and/or acetylcholine is generated which has the property of causing vessel dilatation (vasodilation) swelling, itching, pain and rash.
Chronic and recurring urticaria is a challenging problem for the medical world as on most occasions the exact cause remains unknown. Unfortunately, chronic urticaria is treated only symptomatically using the conventional medicines. What causes urticaria is more difficult to answer than what happens during urticaria, as we described on the earlier page. In almost half the cases we know what causes or induces urticaria; and half the time, we or the patients have no clue to its exact causation.
Acute urticaria is a condition where one experiences urticaria for a short time, may be for a few minutes. However, chronic or recurring urticaria is a major problem, as urticaria keeps appearing again and again, say 3-4 times in a day for a few months or few years. Chronic urticaria is a real challenge, where homeopathic treatment is required.
We shall try to examine some of the most common exciting factors known to induce chronic urticaria, which may be grouped as:
Allergens: A large number allergens have been identified as causative agents for some cases of urticaria. It may be noted that urticaria is an individual hypersensitivity and the following factors may not cause urticaria in all urticaria-prone individuals.
Food allergens: Milk, cheese, egg, protein products, wheat, cereals, certain deals as used in India, peas, orange, fish, chicken, etc. Synthetic and natural food additives and artificially flavored food articles.
Environmental factors: Exposure to pollen, house-dust, buffalo dander, fungi, change in temperature, etc. are known exciting factors. Extreme cold, heat, pressure may induce urticaria.
Drugs: Man made drugs are major cause for urticaria. Antibiotics (Penicillin), anti-inflammatory medicines (aspirin, indomethacin), vaccinations and foreign sera, hormonal preparations, contraceptive pills, etc. are few common ones. Animals treated with penicillin excrete a small amount of it in the milk sufficient to cause urticaria in sensitive individuals.
Infections and Infestations: Insect bites, fungal, protozoal, frequent bacterial infections (Urinary tract), viral infections (Hepatitis), helminthiasis (worm infestations such as round worms, tapeworms), etc. are factors known to cause urticaria. Domestic contact with the pet animals should be examined as cause for urticaria.
Synthetic products: Use of personal products such as deodorant, perfume, talcum powder, cosmetic products, animal derivatives, and similar synthetic substances may induce this disorder.
Emotional factors: Especially in chronic, recurring cases of urticaria the role of emotional factors must be examines. Emotional stresses may directly or indirectly make on susceptible to develop a tendency to urticaria. The psychological factors may work as exciting, aggravating or maintaining cause.
Systemic and General Disease: Urticaria in some cases may present as a sign of other systemic or general internal disease such as hormonal disorders (hyperthyroidism), SLE, polycythaemia, reticulosis. In certain variety of malignancies (cancer) urticaria may present as a precursor
Idiopathic causes: No list of causation is complete without adding a paragraph of ‘Idiopathic’ which simply implies those causes which are unknown. Urticaria is one of the many disease of which the exact cause is not fully understood.