Urticaria: types, causes and prevention

Urticarial rashes usually respond to an allergic reaction. But psychosomatic causes, autoimmune processes and even reactivities at ambient temperatures have also been identified.

Last update: December 19, 2021

Urticaria manifests itself through transient, intensely itchy skin eruptions. As explained by the magazine Dermatology PeruThe typical lesion is the wheal, which varies in size and shape. The condition harms people of any age.

Data from the Spanish Association of Pediatrics report that disorders of this type represent one of the most frequent reasons for medical consultations, affecting between 10 and 20% of the population at some point. In addition, recent studies point to this condition as a symptom occasionally linked to cases of COVID 19.

Causes of hives

The pathology is associated with allergic reactions due to the ingestion of certain foods, extreme changes in temperature, animal dander, exposure to pollen, insect bites and the consumption of some medications.

Psychosocial processes, such as stress, also influence this condition of immune hypersensitivity, indicates the journal of the Faculty of Health Sciences UDES. Also, the newsletter Peruvian Medical Act states that urticaria originates once, to defend itself against infection, the body releases histamine and other vasoactive substances, causing the extravasation of plasma fluid towards the skin. If the irritation reaches the deeper layers it becomes angioedema.

The raised lesions of urticaria are bothersome when they cause severe itching.


Symptoms of the rash

Urticarial rashes appear in batches and show the following characteristic signs:

  • Red spots, the same color as skin or whitish if pressed.
  • Lumpy erythema elongated or in the form of rings in any part of the body.
  • Hives accompanied by itching.
  • Itch light to intense.
  • Swollen tongue and glottis in the most serious cases, which lead to respiratory distress, as stated by the Clinic of the University of Navarra.

Red rosettes are the most obvious symptoms of the condition

Types of hives

Urticarias of spontaneous or unknown origin are often present. There are also episodic ones, which are intermittent and can be relieved with natural remedies. However, it is possible to break them down by their clinical features into the following varieties.

1. Acute

Rashes that last less than 6 weeks are acute. They are injuries linked to infections and it is common for children to suffer them. Treatment is based on antihistamines. If the condition worsens, corticosteroids are prescribed.

2. Chronicle

The Colombian Association of Dermatology and Dermatological Surgery highlights that hives from chronic urticaria take more than 6 weeks to go away. Before addressing them, it is suggested to rule out autoimmune diseases. Although they are almost never serious, these inflammations disturb the quality of life.

3. Dermographism

Also called dermatographism, it is a form of urticaria of the acute type. It happens when you rub your skin too much. It lasts a few minutes and is expressed in lines at the scratch site.

4. By delayed pressure

Delayed pressure injuries are those that manifest at least 6 hours after pressing the hands, buttocks, shoulders or the soles of the feet. There is inflammation and it is difficult to identify what caused it, because the lump shows when the pressure disappears.

5. Induced by infections

These erythema respond to bacterial or viral pathologies. For example, urinary tract infections and hepatitis are classic examples of etiologic agents.

6. Induced by temperature

People who are sensitive to changes in temperature in the environment are prone to the following types of hives:

  • By cold: Low temperatures cause hives, itching, and swelling, so avoiding dips in the pool or sea is recommended for these patients.
  • By heat: It occurs hours after contact with hot water or radiant energy. In this block is added the urticaria suffered by exposure to the sun’s rays. It disappears at approximately 3 hours.
  • Cholinergic: They are hives on the trunk or abdomen, a product of sweat, physical exercise and hot baths. The rosettes fade as soon as the body temperature normalizes.

7. Angioedema

Angioedema swellings transcend soft areas of the skin: eyelids, back of the hand, lips, tongue, mucous membranes, glottis, scrotum. It is the accumulation of plasma deep in the skin and sometimes it does not respond to antihistamines or corticosteroids.

Angioedema is a slightly more aggressive presentation of hives that causes fluid accumulation in soft tissues.

8. Vibratory angioedema

Vibratory angioedema has erythema lasting half an hour after using vibratory devices, jogging, or rubbing a towel on the skin. It is a rare form of presentation.



How to diagnose hives?

The Spanish Academy of Dermatology and Venereology released a guide in which it specifies how to diagnose the different kinds of urticaria. For the acute, the physical examination and specifying the symptoms is key, without the need for a blood test.

In the case of chronic disease, other possible skin diseases must be ruled out, as they warrant a different approach. Similarly, the dermatologist considers provocation tests to determine activation thresholds.

When the lesions correspond to an allergic reaction, Preventing them will depend on lifestyle changes. These patients must watch their diet, avoid substances that cause the condition, reduce exposure to risk factors, and opt for allergy shots.

Although some rashes are momentary and go away on their own, feel free to see a doctor in case of outbreaks that swell the tongue or the area around the throat and prevent breathing.

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