Definition of Chronic or Acute Urticaria, Causes and Treatment

Urticaria is a lesion of the skin whose main characteristic is the formation of papules (circular elevations, prominent and well-demarcated) surrounded by red welts (erythema) and swelling (edema).

Plaques or welts sting very often. They can appear suddenly in any region of the body and disappear spontaneously to reappear later, in some cases, in other places. In general, its appearance is associated with the action of histamine, a substance released by mast cells, connective tissue cells responsible for the dilatation and permeability of small blood vessels.

Depending on the duration of the crisis, the hives can be classified as acute urticaria (lasting less than six weeks or consisting of a single transient and self-limited onset) or chronic urticaria when the condition persists for more than six weeks.

There are cases in which the rash is accompanied by angioedema, an inflammation of the deeper layers of the dermis, which mainly affects the eyelids, lips, ears, feet, hands, and genitals. Although rare, angioedema can affect the mouth and throat mucosa to the point of airway obstruction and laryngeal edema (Quinck’s swelling); severe disease complications are life-threatening.

Urticaria is a pervasive disorder. Studies show that around 20% and 25% of people have expressed at least one episode of the disease.

Causes of Urticaria

Acute urticaria can be triggered by stimulation of immune or non-immune origin. In non-immune origin, the rash is the result of an acute allergic reaction to physical agents, such as certain medications (aspirin, diclofenac penicillin, an antihypertensive …), some foods (seafood, eggs, nuts, milk, chocolate, preserves … ), insect bites, or a reaction to direct skin exposure to cold, heat, sunlight, water (hot and cold), physical exercises. Injuries can also arise in areas of skin under pressure or that have suffered injuries.

Hepatitis, infectious mononucleosis, and rubella are examples of viral infections that may be associated with the appearance of urticaria as the first manifestation of these diseases.


It is tough, however, to establish the activation of most episodes of chronic urticaria. Recent studies indicate that many of these cases may be associated with an autoimmune disease.


Among the symptoms, we have intense itching and burning, signs that may precede the appearance of papules or small white or pink elevations, with the lighter center delimited by hives and reddish swelling.

The size of the lesions varies significantly because the lesions can erupt isolated or form plaques in bulk. Although they disappear without leaving marks on the skin, they can again manifest themselves in any other region of the body.

Symptoms such as shortness of breath and difficulty swallowing and speaking, although rare, are severe complications of both urticaria and angioedema and require urgent medical attention.


The patient’s medical history, eating habits, drug use, and injuries are essential data for diagnosing urticaria. Blood tests and skin tests can be helpful to identify the cause and triggers, as well as to establish the differential diagnosis with other skin diseases.

Unfortunately, this is not always possible, and some cases are classified as chronic idiopathic urticaria.

Treatment of Urticaria

Whenever it is possible to identify the cause of the lesions, the treatment of urticaria consists in completely suspending contact with the agent that activates the symptoms.

Antihistamines, oral drugs, help relieve symptoms by inhibiting histamine receptors’ action. In more severe cases, mainly when associated with angioedema, it may be necessary to introduce drugs with steroids in the medical formula.

Medications for local or topical use do not usually give effective results in treating urticaria.


* Stay tuned. If you already know the trigger for the outbreaks of urticaria, stay away from it. This is the surest way to avoid crises.

* Avoid scratching the skin, especially in the areas where the lesions developed.

* Apply cold compresses on the lesions to relieve the itching characteristic of urticaria.

* Take the person immediately to the medical and hospital services if symptoms of acute urticaria appear, such as difficulty breathing, speaking, or swallowing.