Urticaria Children Allergy Urticaria

Urticaria in children and urticaria allergy

        Patients with urticaria are very numerous in both acute and chronic. Hives are the result of activation of cells of skin allergy (mast) not necessarily linked to an allergy. It owes its name to the typical lesions from contact with plants. It is noteworthy that the circadian cycle of mast cells explains the achievement of injury exacerbation evening to night and the absence of residual lesions in the late morning to the great displeasure of the patient who came to see the emergency physician after a night of horrible itching ...

        Many acute urticaria are caused by infectious diseases (hepatitis virus, coxsackie, CMV etc ...) or related to a toxic overdose substances like chocolate, coffee, tea, etc. Some are facilitated by underlying diseases (hyperthyroidism, Lupus, chronic hepatitis, etc ...). Of course there is a rash of "neurological" or "psychological" but it is a differential diagnosis often witness to our ignorance and politely hiding another reality. We must nevertheless recognize that "he / she gives me hives" is the oral witness to this phenomenon.

        The usual causes of allergic urticaria are mainly food (the allergen in question varies with age) but the air allergens (pollens, mites, mold ...) should not be overlooked especially in patients suffering from other forms of 'immediate allergy (rhinitis, conjunctivitis, asthma ...). The chemical forms are currently the least well known: the GERDA attributed the role of formaldehyde, the rosin, the ppd, balsam of Peru and many other substances usually placed in "delayed allergy" but effects "immediate" are clear (the mechanism is not IgE mediated by the way). Increasingly it also involves chemical association (eg perfumes) and UV photosensitization with whose diagnosis is very laborious (photo-patch tests in specialized units and correlated to the dose of UV activation).

Urticaria etiology

        Hives may accompany an acute angioedema requiring urgent care and specific treatment. The possible causes are many:

• The iatrogenic urticaria: beta-lactams, iodine, etc ... but the drug-induced dermatitis may take all aspects including bullous. The immediate urticarial reactions (start less than 1 hour) and accelerated (beginning between 1 and 72 hours) following administration of penicillin are often mediated by IgE and thus represent a higher risk if taken later.
• The rash that appears on food because of a food allergy are (ie, IgE-dependent) half the cases. Urticaria reaction is caused by histamine release by food intolerance. There may be a dose-dependence and phenomena associated with alcohol, fatigue.
• The most common are: strawberries, shellfish, exotic fruit, tomato, chocolate, fermented cheese, sauerkraut, canned meats, spinach, etc.
• The rash of viral origin are also common: hepatitis, coxsakies, measles, etc.
• Helmintes, Lambiase, flukes, etc.
• Latex allergy can manifest hives.

        The contact urticaria is triggered:

• Any urticarial molecules carried by the animal (jellyfish), plants (nettle).
• Either a real mechanism of contact allergy (eg latex), ointments, soaps, perfumes, etc.
• By cold urticaria.

Urticaria in children pictures