Definition of urticaria
Urticaria is a rash that is characterized by itching and the appearance of raised red patches (“papules”), which resemble stinging nettles (the word urticaria comes from the Latin urtica, which means nettle). Urticaria is a symptom rather than a disease, and its causes are multiple. We distinguish:
- acute urticaria, which is manifested by one or more outbreaks lasting a few minutes to a few hours (and may reappear for several days), but evolving for less than 6 weeks;
- Chronic urticaria, which results in almost daily attacks, lasting for more than 6 weeks.
When urticaria is recurrent but not continuous, recurrent urticaria is called recurrent urticaria.
Symptoms of the urticaria crisis
Urticaria results in the occurrence of:
- papules in relief, resembling stinging nettles, dew or red, of variable size (a few millimeters to several centimeters), appearing most often on the arms, the legs or the trunk;
- itching (pruritus), sometimes very intense;
- In some cases, swelling or edema (angioedema), mostly affecting the face or extremities.
Typically, the urticaria lesions are fleeting (them last from a few minutes to a few hours) and disappear spontaneously without leaving any scars. However, other lesions can take over and the crisis can persist for several days.
In some cases, other symptoms are associated:
- a moderate fever;
- abdominal pain or digestive disorders;
- joint pain
People at risk for Urticaria
Everyone may be prone to hives, but some factors or diseases can make it happen.
- female sex (women are more frequently affected than men3);
- genetic factors: in some cases, manifestations occur in infants or young children, and there are several cases of urticaria in the family (cold family urticaria, Mückle syndrome and Wells);
- blood abnormalities (eg cryoglobulinemia) or deficiency of certain enzymes (C1-esterase, in particular) ;
- Certain systemic diseases (such as autoimmune thyroiditis, connective tissue disease, lupus, lymphoma). About 1% of chronic urticaria is associated with systemic disease: there are other symptoms5.
Several factors can trigger or aggravate seizures (see Causes). The most common are:
- taking certain medications
- excessive consumption of foods rich in histamine or histamine-liberators;
- Exposure to cold or heat.
Who is affected by hives?
Everyone can be touched. It is estimated that at least 20% of people have acute urticaria at least once in their lives, with women being more often concerned than men.
In contrast, chronic urticaria is rarer. It concerns 1 to 5% of the population 1.
In many cases, people with chronic urticaria are affected for many years. It turns out that 65% of chronic urticaria persists for more than 12 months, and 40% persist for at least 10 years.
Causes of the disease
The mechanisms involved in urticaria are complex and poorly understood. Although acute urticaria attacks are often due to an allergy, most chronic urticaria is not allergic.
Some cells called mast cells, which play a role in the immune system, are involved in chronic urticaria. In affected individuals, mast cells would be more sensitive and trigger, by activating and releasing histamine, inappropriate inflammatory reactions.
The different types of urticaria
If the mechanisms are not well known, it is known that environmental factors can aggravate or trigger urticaria attacks.
In nearly 75% of cases, the acute urticaria crisis is triggered by specific factors:
- A drug triggers the crisis in 30 to 50% of cases. Just about any medicine can be the cause. It may be an antibiotic, anesthetic, aspirin, a nonsteroidal anti-inflammatory drug, a drug to treat high blood pressure, iodinated contrast medium, morphine, codeine, etc. ;
- a food rich in histamine (cheese, canned fish, sausages, smoked herrings, tomatoes …) or so-called “histamine-liberator” (strawberry, banana, pineapple, walnuts, chocolate, alcohol, egg white, sausages, fish, crustaceans …);
- contact with certain products (latex, cosmetics, for example) or plants/animals;
- cold exposure;
- exposure to the sun or heat
- pressure or friction of the skin;
- an insect bite;
- Concomitant infection (Helicobacter pylori infection, hepatitis B, etc.). The link is not well established, however, and the studies are contradictory;
- emotional stress;
- Intense physical exercise.
Chronic urticaria can also be triggered by any of the factors listed above, but in about 70% of cases, no causal factors are found. This is called idiopathic urticaria.
Evolution and possible complications
Urticaria is a benign condition, but it can have a considerable impact on the quality of life, especially when it is chronic.
Some forms of urticaria are more worrying than others. Indeed, urticaria can be superficial or deep. In the second case, we observe painful edema (oedemas) of the skin or mucous membranes, which appear mainly on the face (angioedema), hands and feet.
If this edema affects the larynx (angioedema), the vital prognosis can be engaged because breathing becomes difficult or impossible. This case is fortunately rare.
|Can we prevent?|
|In most cases, it is impossible to prevent urticaria attacks. However, if certain factors tend to trigger or aggravate the seizures, it is important to identify them and avoid them as much as possible (especially drugs such as NSAIDs, aspirin, codeine, physical factors such as cold or hot, as well as histamine-releasing foods). In order to identify these triggers, it is useful to note the date and time of onset of seizures as well as the list of foods or drugs consumed within 24 hours of the outbreak.
Finally, if you are subject to angioedema or angioedema, your doctor will probably prescribe an emergency kit (containing antihistamines or adrenaline (epinephrine), to be stored on you at all times, to deflate rapidly ‘edema.
Medical treatments of Urticaria
Unfortunately, there is no treatment that eliminates the causes of urticaria and treats it permanently.
Acute urticaria usually disappears of itself in a few hours.
However, a treatment can be prescribed. It is mainly intended to avoid recurrences and it is based on:
- the eviction of the triggering factor, if known
- Taking an antihistamine medication for a few days, if the symptoms warrant it.
If the urticaria is generalized and / or accompanied by facial edema, corticosteroids can also be administered for a few days (orally most often). These, however, have no utility in chronic urticaria and should even be avoided.
In the case of angioedema or tongue or palate (swelling), here are the emergency treatments given at the hospital:
– Adrenaline spray (epinephrine)
– Intravenous adrenaline
Chronic urticaria 6
The treatment of chronic urticaria is primarily based on antihistamines (anti-H1), such as cetirizine, fexofenadine or levocetirizine or desloratadine.
The treatment is prescribed for a variable duration (at least 2 weeks and often 3 to 6 months depending on the recommendations, which vary from one country to another). These drugs are generally well tolerated but can induce drowsiness. It is therefore advisable to take them at night and not to drive within hours of taking (refer to the leaflet).
It is important to take these medications regularly, following the prescription, even if the symptoms fade.
The doctor usually evaluates the effectiveness of the treatment after 2 weeks. If symptoms persist, he or she will adjust the dose, or change the antihistamine. If the treatment is effective, it will be stopped gradually after 3 months (or more), after obtaining a satisfactory and lasting improvement.
If antihistamine treatment is ineffective, several options may be offered:
- the addition of an anti-leukotriene drug (montelukast in Canada), generally used for the treatment of asthma;
- The search for the presence of an allergy or a systemic disease that can sustain urticaria. Medical examinations will also be carried out to find the presence of an infection, a drug or food intolerance, a blood abnormality, etc …
In case of failure of these treatments and investigations, and if we find no cause for urticaria, which is common, drugs such as ciclosporin, dapsone, H2 antihistamines or omalizumab may be proposed on a case by case basis. Their effectiveness varies from person to person.
Chronic urticaria very often has a significant impact on the quality of life, because of its chronic character and its visible and disturbing manifestations.
It is therefore important, if we feel the need, to benefit from psychological counseling 7, which will be adapted on a case by case basis.
Follow-up can be based on:
- stress management techniques such as relaxation, meditation …
- Anti-depressants or psychotropic drugs in case of the depressive syndrome (doxepin, alprazolam, fluoxetine, sertraline …).