Q. What is urticaria?
A. Urticaria is the sudden occurrence in the skin of red itchy swollen patches. It appears in one area and disappers quickly in minutes or hours from there, only to reappear in another area. Urticaria may be localized at some part of the body or spread all over the body. It may occur as only a few spots or it may be confluent or joined together.
Q. Who are the people more likely to get urticaria?
A. Urticaria is a manifestation of allergy. People with a family history of allergy, are more likely to develop it at one time or another. But even those who have no family history of allergy also get it.
In the majority of the cases, it is a transient phenomenon occuring only once or twice. In some people, it comes up only in a particular season; in others, it persists for weeks, months and years, making life miserable.
Q. What are the causes of urticaria?
A. Some of the causes of urticaria are :
1. Physical agents such as cold, heat, sunlight and mechanical pressure.
2. Emotional causes such as laughter, anxiety and panic.
3. Food articles such as nuts, seeds, fish, milk, eggs, citrus fruits.
4.Drugs,outofwhichasprin isthecommonoffender. Others are antibiotics, laxatives, etc.
5. Inhalation of certain pollens or chemicals or fibres such as of nylon or wool.
6. Unknown causes which form the majority of the cases. Urticaria can be caused by allergic as well as non-allergic factors. Allergic mechanism involves the release of histamine in the tissues. There are other chemicals that are also released.
Q. What are the characteristics of urticaria caused by cold?
A. Cold weather, cold winds, bathing with cold water, holding cold drinks in the hands or drinking them, are known to give rise to urticaria in susceptible people. Swelling of the mucous membrane of the mouth, difficulty in swallowing, pain in abdomen, or difficulty in breathing due to swelling of the glottis, are some of the other symptons.
In order to make sure that the symptoms produced are a result of cold, it is necessary to perform a cold immersiontest.Immersionof handofapersonallergic tocoldinwaterat5o Cfor5to10minutesmaybe followed by a reddening and swelling of the hand and apperance of urticarial rash in other parts of the body.
This may happen immediately or after a few minutes. The temperature level at which symptoms appear varies considerably.
Treatment consists, primarily, in the avoidance of exposure to cold. Hyposensitization by exposing the hand or hands to water at progressively lower temperatures may be helpful. The hand is immersed in water at about 15o C for 2 to 5 minutes several times a day, and the temperature of water is gradually reduced on successive days to about 6o C, if the patient tolerates the lowered temperatures. The use of antihistamines is helpful at times, but occasionally it is ineffective.
Q. What are the characteristics of urticaria caused by heat?
A. Heat, exertion or excitment in the form of laughter or pain can bring on urticaria in some cases. Hot baths, exposure to the heat of the sun, eating hot foods, sitting in a warm room or strenuous exersice, can bring on an attack of urticaria.
Diagnosis is made on the basis of the case history, and confirmed by testing for heat exposure by having the patient put one leg in hot water. Attack of generalized urticaria will be induced over the entire body except for the immersed leg which merely becomes flushed.
In treating an acute reaction, any cooling agent such as cold water, cold air, or the application of alcohol to the skin will give some relief. An attempt can be made to increase tolerance by exposing the subject gradually to higher temperatures, beginning by placing the hand in water at about 37o C and increasing the temperature to 43o C, followed by a bath at 37o C. In general, the treatment of allergy to heat is not satisfactory.
Q What are the characteristics of urticaria caused by sunlight ?
A. In some rare cases, urticaria appears on exposure to sunlight.Thisisnotduetoheat,but duetothesunlight itself. Burning sensation is noted within 20 to 30 seconds after the exposure followed by redness and a weal. The reaction may reach a peak in 10 minutes and persist for 1 to 2 hours.
In some cases, reactions occur only after photosensitizing agents have been ingested, such as sulphonamides, or applied to the skin, such as the tar derivatives, contained in some cosmetic creams.
Diagnosis depends on the case history and the reproduction of symptoms by exposure to sunlight. Change of environment, wearing tinted glasses, staying indoors, avoiding known photosensitizing substances, coating the skin with agents capable of filtering out the injurious rays, have given good results in some cases. Treatment is generally unsatisfactory.
Q. Which drugs are known to cause urticaria?
A. Penicillin, aspirin, laxatives, sedatives, hormones and vaccine injections are commonly incriminated. Pencillin either by injection, oral or ointment is considered, by some, to be the commonest cause of urticaria now-a- days.
It is, however, not easy to find out the causative drug, asurticariallesionsoftenappeardaysandweeks after the taking of the drug.
Q. Which foods can cause urticaria?
A. Among the foods that cause urticaria in sensitive individuals, are those eaten raw such as bananas, oranges, strawberries, groundnut, tomatoes and wheat; other suspected foods are eggs, chocolate, fish, lobster, oyster and prawns.
Q. How is the cause of urticaria determined in a particular case?
A. A thorough searching history of the patient is the most important single factor that helps in pinpointing the cause. Physical examination is important particularly with regard to the appearance and distribution of the lesions.
In chronic urticaria, the food that a patient usually takes must be throughly checked. In the case of a patient who gets isolated bouts of urticaria, the causative food may be that which is eaten occasionally. Commonly known allergic articles of diet such as eggs, fish, milk, chocolate, dried fruits etc. be eliminated and the results noted. If there is an improvement in the symptoms, then all the eliminated foods should be re-administered, one by one, and the effect of each noted. There should be an interval of at least one week in between. Urticaria localized continuously or repeatedly at 7 certain areas suggests the possibility of a contact with an allergic substance. Pollens may be implicated when there is seasonal incidence.
Q. Are skin tests helpful in finding the cause of urticaria ?
A. Skin test in these patients with extracts of pollens, dust and foods commonly elicit some positive reactions, but their true significance can only be ascertained after correlating them with the case history and food trials.
Skin tests with the drugs are unreliable and may prove dangerous as well. In spite of best efforts, in a vast majority of cases, the causative agent cannot be found by any means.
Q. How is a case of urticaria treated ?
A. Treatment lies in avoiding the causative agent. If that is not possible, the following measures are adopted.
If an examination of the stool shows presence of a worm, its eradication may in some cases be helpful.
Sites of infection in the teeth, tonsils and other places should be treated appropriately.
Patients should be warned against taking any pain- relieving tablets, laxatives or sedatives.
Q. Is hyposensitization or immunotherapy (injections) of any value in the treatment of urticaria ?
A. Many a time it has not been found to be of much value. 8
Q. What measures are recommended for getting relief from symptoms?
A. For symptomatic relief, various antihistamine tablets are recommended. Hydroxyzine (Atarax) and cyproheptadine (Periactin) are especially effective for the treatment of urticaria caused by cold, heat and exitement.
Q. Are newer antihistamines better than the usual ones in cases of urticaria?
A. Yes. They are longer-acting and cause less drowsiness. They should be tried.
Q. Should corticosteroids be taken as tablets either alone or in combination with antihistamines in cases of urticaria ?
A. Corticosteroids should preferably be avoided. If it is a matter of a week or a fortnight and urticaria is very troublesome, steroids can be given along with anti- histamines. But because urticaria can be a long standing problem, relief obtained from the use of steroids will become a habit and ultimately result in lot of injurious effects on the body.
Q. How useful are herbal remedies for cases of urticaria?
A. Ayurveda and Unani physicians claim good results with their preparations, not only as temporary relief but also for the cure of disease as well. Homoeopathic remedies have also been claimed to provide good results. Those patients who do not find relief, preventive or curative, under modern medicine, and have a long-standing and troublesome disease, may try remedies under these systems of medicine, under the care of a reputed physician.