Hives (also known as Urticaria) is a skin disease that can is classified as one of the so-called“Figurate Erythemas”. Any form of urticaria that lasts for less than 12 weeks is classified as acute (acute urticaria). If the disease lasts for more than 12 weeks, it is classified as chronic (chronic urticaria).
Description
Hives (also known as Urticaria) is a skin disease that is classified as one of the so-called “Figurate Erythemas”. Any form of urticaria that lasts for less than 12 weeks is classified as acute (acute urticaria). If the disease lasts for more than 12 weeks, it is classified as chronic (chronic urticaria).
It is characterized by the development of one or more – usually multiple – hives, i.e. lesions with a white-pink or erythematous complexion, macular round shape, and temporary form. These lesions can be tiny or very big, and sometimes, they are joined together into plaques that can cover large parts of the body.
The skin rash is typically accompanied by itching or even pain, and can be found on any part of the body, from scalp to feet.
In 40% of the cases, it is also accompanied by swelling (its scientific name is angioedema), and as a result, it sticks out of the skin.
Focal form
Μacules in one or more areas.
Segmental form
Μacules only in one half of the body
Generalized form
It is the most common form, with symmetrical macules in both halves of the body.
Causes
Depending on the type of urticaria, the causes may vary as follows:
- Acute allergic urticaria: It is caused by the activation of an allergic reaction through the IgE immunoglobulin. Most patients with this reaction are individuals with atopic predisposition (allergic). The above E (ΙgE) immunoglobulin can be noticed in individuals with hereditary (atopic) predisposition, or caused by contact or the entry of a foreign substance, to which the individual is not accustomed (pollen, house dust, fungi, chemicals, drugs, etc.).
- Chronic allergic urticaria: Chronic urticaria can be spontaneous (i.e., there is not any external cause), or inducible (i.e., it is caused by natural causes, such as heat, cold, and pressure); however, it is not an allergy, in any case. A frequent cause that triggers chronic urticaria is stress.
- Non-allergic urticaria: It is caused by various causes, such as cold, sunlight, contact with a chemical substance, or continuous pressure on the skin.
- Cholinergic urticaria: It develops after fever, a hot shower, or nervous stress, and is characterized by a small wheal and a big erythema.
- Urticaria from natural causes: The natural causes that are implicated in this specific form can be mechanical, thermal, sunlight, water, and from plants, or substances.
Treatment
Acute urticaria usually remits in less than 12 weeks, by using antihistamines.
Chronic urticaria, however, can last for more than 6 months. After identifying its cause, an effort starts to eliminate it, which is not always possible, however, since many cases are idiopathic.
Regarding the itching symptom, antihistamine drugs are administered at first, and possibly corticosteroids (cortisone). If patients with chronic urticaria do not respond even to higher doses of antihistamines, and their skin disease is not due to any external cause, other drugs can be added to their medication, such as antileukotrienes, H2 antihistamines, immunotropic factors, or a monoclonal antibody that is called omalizumab.
Finally, for short chronic urticaria outbreaks, systemic corticosteroids are administered for a few days (usually 3-7).
