What it looks like and how it differs
- Blisters - raised pink or whitish elements of different sizes, with a clear edge
- Severe itching, less often burning sensation
- Elements migrate: disappear in one place and appear in another
- Each individual blister lasts from a few minutes to 24 hours and goes away without a trace
- Often accompanied by angioedema - deep swelling of the lips, eyelids, hands, feet
Если отдельный элемент держится больше суток, болезненный, оставляет синяк или пигментацию — это не обычная крапивница, а повод для обследования, включая биопсию кожи.
Acute and chronic
- Acute (up to 6 weeks): most often associated with a viral infection, less often with medications (NSAIDs, antibiotics), food, insect bites. In children, the leading cause is infection, not food.
- Chronic (more than 6 weeks): in most cases spontaneous, autoimmune in nature, without an external allergen. Extensive allergological examinations are not very informative
- Inducible: provoked by physical factors - cold, pressure, vibration, sun, water, physical activity
Cold urticaria stands out separately: it is dangerous because swimming in cold water can cause a systemic reaction with a drop in pressure. Such patients should not swim in cold water alone.
Survey
For acute urticaria with an obvious trigger, testing is usually not required. For chronic conditions, the reasonable minimum is small.
- Общий анализ крови, СОЭ и С-реактивный белок — исключение воспаления.
- Гормоны щитовидной железы и антитела к ТПО — аутоиммунный тиреоидит нередко сопутствует.
- Обследование на глистные инвазии и хеликобактер — по показаниям.
- Провокационные тесты при подозрении на индуцируемые формы (холод, давление, тепло).
- Биопсия кожи — если элементы держатся дольше суток.
Панели анализов на десятки пищевых аллергенов при хронической крапивнице не рекомендуются: они дают много ложноположительных результатов и приводят к бессмысленным ограничениям в питании.
Treatment
- Second generation antihistamines are basic therapy; taken regularly, not “on demand”
- If the effect is insufficient, the doctor may increase the dose several times - this is a standard approach for chronic urticaria
- A short course of systemic glucocorticosteroids - only for severe exacerbation
- Biological therapy - for severe chronic urticaria resistant to antihistamines
- Elimination of provocateurs: NSAIDs, alcohol, overheating, tight clothing, stress
- If there is angioedema with difficulty breathing, go to an ambulance immediately; for known anaphylaxis - adrenaline in an auto-injector
How to relieve the condition
- Cool showers and cool compresses reduce itching
- Loose cotton clothing, avoid tight elastic bands and belts
- Avoid overheating, hot baths and saunas during an exacerbation period
- Limit alcohol and use of NSAIDs unless necessary
- Keep a diary of rashes: the time that preceded them, the duration of the elements
- Do not scratch - mechanical irritation itself provokes new blisters