What Are Viral Hives?

Pediatric urticaria, commonly referred to as rubella, is a common allergic skin disease with dilated small blood vessels and increased permeability. It is mainly manifested by erythematous and limited edema reactions of varying skin size. It is often accompanied by pruritus, whose basic lesions are temporary dilation of the capillaries of the skin and mucosa and sudden increase in permeability. Most of this disease is caused by allergies, and most of the acute prognosis is good. There are many causes of urticaria. Bacteria, viruses, and parasites can become allergens. Pollen, dust, chemicals, and even some foods can become allergens. Chronic urticaria refers to those who have at least two episodes of wind bouts per week for 6 weeks. A small number of patients with chronic urticaria can also show intermittent attacks.

Basic Information

nickname: Rubella
English name: pediatric urticaria
Visiting department: Pediatrics

Multiple groups: Allergic
Common causes: Various microorganisms, pollen, chemicals, etc. are often the cause of disease
Common symptoms: Skin erythema, wind mass, strange itching, may have nausea, abdominal pain

Causes of urticaria in children

The etiology is complex, and it is not easy to determine the cause. Only 10% to 25% of children may have a clear cause. Caused by some internal and external factors.

Exogenous factor

Mostly temporary, including foods that are prone to allergies (eg eggs, dairy products, shrimps and crabs, shellfish, spices, dyes, etc.), plants or fruits (eg bayberry, lemon, mango, plum, apricot, strawberry, walnut) , Cocoa, garlic, tomatoes, etc., spoiled foods and food additives), drugs (such as sulfa compounds, antibiotics, serum, vaccines, toxoids, morphine, codeine, aspirin, etc.), inhaled allergens (such as pollen, fungi, Spores, animal feathers, dander, aerosols, etc.) or infections (bacteria are more common in Staphylococcus and -hemolytic streptococcus A group, Helicobacter pylori, viruses, fungi, intestinal parasites, etc.). Physical factors such as temperature, cold, heat, sunlight, friction pressure, implants (artificial joints, staplers, heart valves, orthopedic steel plates, nails, etc.) and sports.

2. Endogenous factors

Most are persistent, including mast cells are highly sensitive to IgE, chronic occult infections (bacterial, fungal, viral, parasitic infections, fatigue, and mental stress can also be induced. Some urticaria is accompanied by some systemic diseases, Such as autoimmune diseases, rheumatic fever, systemic lupus erythematosus, rheumatoid arthritis, thyroid disease, lymphoma, leukemia, malignant lymphoma and certain liver diseases, inflammatory bowel disease and so on.

For acute urticaria, food may be the common major allergen, while chronic urticaria has the highest positive rates for dust mites and house dust. Acute urticaria in infants and young children is mainly caused by upper respiratory and digestive tract virus (such as adenovirus, EB virus or enterovirus, etc.) infections, drugs (antibiotics, antipyretics, etc.) and food.

Clinical manifestations of urticaria in children

The typical symptoms of this disease are erythema and wind mass. In typical cases, erythema first appears after exposure to the allergen, followed by wind masses. Wind masses can appear in the center of the erythema and spread around. Clinically, there are only erythema without wind clusters (more common in infants and young children), and sometimes only wind clusters without red patches (more common in older children and adults).

The onset of acute urticaria in children is very sudden, and the skin can be itchy in a flash. With the itching and scratching, red and pale rubella blocks of varying sizes and sizes quickly appear; skin scratches are positive (using a needle in the The scratches on the normal skin of the child may show red consistent with the scratches); the number of rashes is generally large, some are ring-shaped, or they can be merged into a large piece, which subsides quickly within a few minutes to hours. Leave no trace. Hives can occur anywhere in the body. The disease is prone to recurrence, and sometimes appears. Most children do not have any discomfort except for itchy skin. However, if the digestive tract is involved, symptoms such as nausea, vomiting, abdominal pain and diarrhea may occur; if the bronchus and throat are involved, throat blockage, chest tightness, shortness of breath, dyspnea, and even suffocation; some children may also have hands, feet, eyelids, Even the whole face is edema; when it is severe, there are shock manifestations such as pale, dyspnea, and decreased blood pressure. The course of chronic urticaria can be as long as several months or even years. Generally, those with chronic urticaria over 2 to 3 months are called chronic.

In addition, there are many types of this disease, such as acute, chronic, cold, local fever, sunlight, water-borne, oppressive, cholinergic, urticarial vasculitis, serotype, angioedema, etc. .

Urticaria is both an independent disease and a skin manifestation of some diseases. There are many diseases that can cause urticaria, such as infectious diseases: parasitic infections (roundworms, tapeworms, etc.); bacterial infections (caries, alveolar abscess, tonsillitis, otitis media, sinusitis, etc.); viral infections such as Hepatitis B; fungal infections such as tinea pedis, etc .; systemic diseases (such as diabetes, hyperthyroidism, and even underlying tumors in the body).

Pediatric urticaria examination

Usually no more tests are needed for urticaria. Acute patients can check their blood routine to see if the disease is related to infection or allergies. Chronic patients, such as severe disease, long course of disease, or poor response to conventional doses of antihistamine treatment, can consider blood routine, fecal eggs, liver and kidney function, immunoglobulin, red blood cell sedimentation rate, C-reactive protein, complement And various autoantibodies. If necessary, allergen screening, food diary, autologous serum skin test (ASST) and Helicobacter pylori infection identification can be carried out to rule out and determine the role of related factors in the pathogenesis. An allergen skin test is one of the common methods for finding allergens. The skin allergen test is performed by performing multiple puncture of the allergen skin test solution on the subject's upper arm to observe the allergic reactions of various foods. Positive results require a comprehensive clinical analysis to determine whether they are allergens.

Diagnosis of urticaria in children

It is not difficult to diagnose according to the clinical manifestations of this disease. The key is to determine the cause (allergen).

Differential diagnosis of urticaria in children

It is mainly distinguished from urticaria vasculitis. The main point is that the wind mass of urticaria vasculitis usually lasts for> 24 hours. Pigmentation remains after the skin lesions are recovered, and pathology suggests vascular inflammation. It also needs to be distinguished from other diseases that manifest as wind mass or angioedema, such as urticaria drug eruption, serum sickness-like reaction, papular urticaria, Staphylococcus aureus infection, and hereditary angioedema.

Pediatric urticaria treatment

1. Find and clear allergens

Treatment of the diseases that cause urticaria, autoimmune urticaria is difficult to treat, and intravenous immunoglobulin or plasma dialysis can relieve symptoms.

2. Apply antipruritic lotion topically

Such as calamine lotion (with menthol) or zinc oxide lotion.

3. Drug treatment

(1) Oral antihistamines. Commonly used first-generation antihistamines include chlorpheniramine maleate, promethazine hydrochloride, diphenhydramine, doxepin, and ketotifen; second-generation H1 Receptor antagonists have the advantages of good curative effect and no obvious central inhibitory effect. They can be used in children over 2 years of age. Second-generation antihistamines include cetirizine hydrochloride, loratadine, levoctirizine, and desloride. Statin, fexofenadine, atorvastatin, ebastine, ibistine, mizolastine, olostatin, etc. Take it orally once daily. Calcium and vitamin C can reduce the permeability of capillaries, which is conducive to the relief of symptoms. H2 receptor antagonists (such as cimetidine and ranitidine) combined with H1 receptor antagonists can treat acute urticaria with obvious abdominal pain. Cyproheptadine can be used for the treatment of chronic or cold urticaria.

(2) For stubborn cases, prednisone tablets can be used orally or hydrocortisone intravenously, but not for conventional medication.

There are significant differences in the minimum age limit and dosage of different drugs, and they should be used in accordance with the drug specifications. In children who fail to treat, the first-generation (night use) and second-generation (day use) antihistamines can be combined, but care should be taken to avoid sedative antihistamines in school-aged children.

4. Symptomatic treatment

Children with bronchospasm or laryngeal edema can be injected subcutaneously with 1: 1000 epinephrine solution.

5. Desensitization treatment

For chronic urticaria that is not treated well with conventional drugs, corresponding desensitization treatment can be given according to the results of the allergen skin test, which can often achieve a certain effect.

Prognosis of urticaria in children

The treatment of acute urticaria in children is relatively easy, and anti-allergic treatment, the rash in most children can quickly disappear. The treatment time of chronic urticaria needs to be prolonged. A few patients have recurrent episodes of chronic urticaria, which is called chronic refractory urticaria. This type of urticaria often brings great difficulties to treatment because the allergen cannot be detected.

Urticaria prevention in children

1. Focus on diet

The incidence of urticaria is related to diet, and certain foods may be the cause. For example, fish and shrimp seafood, canned foods containing artificial additives such as artificial colors, preservatives, yeasts, pickled foods, beverages, etc. can induce urticaria. In addition, irritating foods such as too hot and sour will also reduce the digestive function of the gastrointestinal tract, leaving food residues in the intestine for too long, resulting in peptone and peptides, increasing the chance of body allergies.

2. Pay attention to hygiene

Preventing mites in the home is important; keep pets such as cats and dogs at home. Keep children away from pollen-like substances, and avoid moving around the bottom of trees and grass.

3. Pay attention to weather changes

Keep warm to avoid cold urticaria; children with urticaria should wear loose and breathable clothing to avoid irritation to the affected area.

4. Pay attention to drugs

Some drugs can cause urticaria, such as antibiotics such as penicillin, tetracycline, chloramphenicol, streptomycin, sulfa drugs, polymyxins, analgesics, aspirin and other antipyretic analgesics. If you have allergic symptoms when using these drugs, you should stop using them immediately, and use urticaria combination therapy in time.

5. Pay attention to rest

Ensuring adequate sleep and regular life to enhance the body's immunity.