Spontaneous acute urticaria involves a one-off episode that lasts a few days or weeks with the unmistakable symptoms and discomforts of urticaria. The clinical picture therefore usually develops within hours or a few days and then slowly abates again. The causes are not always clear. In many cases, however, it is possible to state precisely the circumstance that triggered the symptoms, e.g. an infection and/or the ingestion of pain tablets or other drugs (including those which were previously tolerated well).
In most cases (> 90 %), a spontaneous acute urticaria lasts only a few days to weeks and can be well controlled therapeutically in this period. Treatment of acute urticaria consists primarily in the suppression of symptoms, and in general it is neither necessary nor practical to conduct an intensive search for causes. If it is suspected that the urticaria is due to an allergy, e.g. against food, it may be sensible to undergo an allergology examination. The more decisive factor is to recognise and treat possible complications (shortness of breath or discomfort in swallowing) and to avoid possible triggers to the extent that they are known.
During spontaneous acute urticaria flares, wheals and/or angioedema appear, i.e. the typical symptoms of urticaria. The wheals are accompanied by severe itching and sometimes by burning and pain in the skin, too (Ill. 9).
While the wheals appear on all body areas, angioedema (deep swelling in the skin) frequently occurs in the area of the face or on hands and feet or in the genital area.
Serious spontaneous acute urticaria may lead to an elevated body temperature, besides headaches, diarrhoea, breathing difficulties, joint pain, fatigue and exhaustion may occur. It is often not clearly distinguishable whether these symptoms are directly attributable to urticaria or an underlying infection.
Among the more common causes of acute urticaria are infections (e.g. of the respiratory tract), drug intolerances (e.g. acetylsalicylic acid, which is contained, among others, in Aspirin® and Thomapyrin®) food allergies/intolerances. By contrast detergents or personal hygiene products such as shampoos, creams or shower gels hardly ever trigger urticaria. Drugs which more frequently trigger urticaria:
Principally almost all drugs can trigger spontaneous acute urticaria. An important indicator is a close temporal connection between beginning drug administration and the beginning of the urticaria symptoms. The diagnosis of a drug allergy should be made with great caution as it means that the patient may no longer receive the drug in future.
As a rule it is not necessary to carry out extensive examinations or even a complex search for the triggers and causes of a spontaneous acute urticaria. Firstly, in many cases the cause is obvious, for instance when the urticaria appears in the upper respiratory tract during an infection (“Flue”, “Cold”) or after ingesting a drug (e.g. Aspirin®). Secondly, in most cases spontaneous acute urticaria heals within a few days or weeks. Further examinations are only sensible if a true allergic reaction is suspected or another serious underlying disease.
Fortunately enough and in most cases it usually only takes a few days before the symptoms of acute urticaria subside on their own. This type of urticaria is therefore only treated symptomatically, i.e. the appearance of wheal, itchiness and/or angioedema is suppressed by drugs, so-called antihistamines (also called allergy medications). Thereby a higher dose may be necessary for some days or weeks. The antihistamines should be taken regularly during this episode and not only optionally as needed. If the bout of spontaneous acute urticaria is severe and is accompanied by angioedema, difficulty in swallowing or respiratory distress, further drugs (such as, for instance, cortisones) should be administered. Locally applied therapeutic substances are of little use. Of course suspected triggers, when and where possible, should be avoided in future.