Why can't you blow dry the air when you have urticaria?

Many people may not understand why people with urticaria cannot be exposed to wind. Urticaria is a common skin disease that causes redness, some in flakes, some slightly higher than the skin, and is accompanied by symptoms such as pain and itching. There are many causes of measles. When you sweat, the pores on your body are open, and you are prone to this disease if you are exposed to the wind. Let’s take a closer look at why people with urticaria should not be exposed to wind.

1. Skin scratch urticaria/artificial urticaria

The patient's physiological response to weak external mechanical stimulation is enhanced, causing wheals on the skin. After scratching, or when wearing tight belts or garters, the patient will develop local wheals and itching.

2. Delayed dermatographism

Skin scratches will cause wheals and erythema 6 to 8 hours after stimulation, and the wheals will last for 24 to 48 hours. There is more than one delayed skin lesion, and small segments or dots are formed along the scratch. The lesions are deeper or wider, and even expand to both sides to form lumps. Local fever and tenderness.

3. Delayed pressure urticaria

The rash develops 4 to 6 hours after local skin pressure is applied and usually lasts 8 to 12 hours. Symptoms include localized, deep, painful swelling, which may be accompanied by chills, fever, headache, joint pain, malaise, and a mild increase in white blood cell count. Large local swelling resembles angioedema and is prone to occur on the palms, soles, and buttocks. There may be a 24-hour incubation period before the lesions occur.

4. Cholestatic urticaria

The rash is characterized by the occurrence of diffuse small wheals of 1 to 3 mm in size except on the palms and soles, with obvious surroundings. Satellite wheals can sometimes be seen among them, or tiny sparse wheals with or without red halos may be seen. Sometimes the only symptom is itching without wheals. The damage lasts from 30 to 90 minutes, or up to several hours. It mostly occurs during or shortly after exercise, accompanied by itching, tingling, burning, heat or skin irritation. It can also be triggered by heat or emotional tension.

5. Cold urticaria

It can be divided into two types: familial and acquired. The former is relatively rare and is inherited in an autosomal dominant manner. A delayed reaction occurs half an hour to four hours after exposure to cold. The rash is a non-itchy wheal that may have a cyanotic center surrounded by a pale halo. The rash lasts for 24 to 48 hours and has a burning sensation, accompanied by systemic symptoms such as fever, joint pain, and increased white blood cell count. The latter is more common, and patients often experience it when the temperature drops suddenly or after contact with cold water. Within minutes, itchy edema and wheals occur locally, most often on the face and hands. In severe cases, other parts of the body may also be affected. Headache, flushing of the skin, low blood pressure, and even fainting may occur.

6. Solar urticaria

A few minutes after the skin is exposed to sunlight, itching, erythema and wheals quickly appear locally. The wheal disappears after about 1 to several hours. The rash may be accompanied by chills, fatigue, fainting, and intestinal cramps, which disappear within a few hours.

7. Contact urticaria

It is characterized by wheals and erythema when the skin comes into contact with certain allergens. It can be divided into two categories: immune mechanism and non-immune mechanism. Non-immune disease is caused by the direct action of primary irritants on mast cells to release substances such as histamine. Almost all contacts will become ill without the need for substance sensitization. The immunity is a type I allergic reaction, and specific IgE antibodies can be detected.

In addition, there are rarer types of urticaria such as heat urticaria, exercise urticaria, tremor urticaria, aquagenic urticaria, adrenergic urticaria, and electrical urticaria.

1. General treatment

Because the causes of urticaria vary, the treatment effects are also different. The specific treatment measures are as follows:

(1) Eliminate the cause. Every patient should strive to find the cause of the attack and avoid it. If the cause is infection, the infected lesions should be treated actively. If the allergy is caused by drugs, the allergy medication should be stopped; if the allergy is caused by food, find out the allergic food and do not eat this food again.

(2) Avoid inducing factors. For example, for cold urticaria, you should keep warm; for acetylcholine urticaria, you should reduce exercise, sweating and mood swings; for contact urticaria, you should reduce the chance of contact.

2. Medication

(1) Antihistamine drugs ①H receptor antagonists have strong anti-histamine and anti-other inflammatory mediator effects and are effective in treating various types of urticaria. Commonly used H1 receptor antagonists include diphenhydramine, cyproheptadine, chlorpheniramine, acrivastine, cetirizine, mizolastine, loratadine, ebastine, azelastine, desloratadine, etc.; when single treatment is ineffective, two different types of H1 receptor antagonists can be used in combination or in combination with H2 receptor antagonists. Commonly used H2 receptor antagonists include cimetidine, ranitidine, famotidine, etc. It is effective for acute, chronic urticaria and cold urticaria. Dosage varies from person to person. ② Doxepin is a tricyclic antidepressant that is particularly effective for chronic urticaria and has fewer adverse reactions. Doxepin is a better choice of drug for patients with urticaria who are not responsive to traditional antihistamines.

(2) Drugs that inhibit mast cell degranulation and reduce histamine release ① Meta-hydroxyisobutyrine sulfate is a β2 adrenergic receptor stimulator that can increase the concentration of cAMP in the body, thereby inhibiting mast cell degranulation. ② Ketotifen inhibits mast cell degranulation and prevents the release of inflammatory mediators (such as histamine, slow-reacting substances, etc.) by increasing the concentration of cAMP in the body. Its suppressed. It is stronger and faster than sodium cromoglycate and can be taken orally. ③Sodium cromoglycate can block the binding of antigen and antibody and inhibit the release of inflammatory mediators. If used in combination with glucocorticoids, the dosage of the latter can be reduced and the therapeutic effect can be enhanced. ④ Tranilast reduces the release of histamine by stabilizing the mast cell membrane.

(3) Glucocorticoids

It is a second-line drug for the treatment of urticaria. It is generally used when severe acute urticaria, urticarial vasculitis, pressure urticaria are ineffective with antihistamines, or when chronic urticaria is severely stimulated. It is given by intravenous drip or orally, and long-term use should be avoided. Commonly used drugs are as follows: ① prednisone; ② triamcinolone; ③ dexamethasone; ④ diprosone. In emergency situations, hydrocortisone, dexamethasone, or methylprednisolone is given intravenously.

(4) Immunosuppressants

When patients with chronic urticaria have an autoimmune basis, the disease recurs, and the above treatments cannot achieve satisfactory results, immunosuppressants can be used. Cyclosporine has a good therapeutic effect. Azathioprine, cyclophosphamide, methotrexate and immunoglobulin can all be tried. Tripterygium wilfordii also has a certain therapeutic effect. Due to the high incidence of side effects of immunosuppressants, they are generally not recommended for the treatment of urticaria.

1. Cholestatic urticaria

It often occurs in adolescence, after exposure to heat (hot drinks, hot baths), emotional excitement, and exercise. The rash is characterized by small wheals of 1 to 3 mm in size with red halos on all sides, mostly on the trunk and proximal extremities, and is pruritus. Some patients also have gastrointestinal symptoms, such as abdominal pain, diarrhea, etc.

2. Solar urticaria

The main phenomenon is that after the skin is exposed to sunlight for a few seconds to a few minutes, itching, erythema, wheals, and angioedema will occur rapidly and last for 1 to 2 hours. It is more common in women.

3. Compression urticaria

It occurs after the skin is subjected to heavier and longer-lasting pressure for 4 to 6 hours. Diffuse, unclearly defined edematous painful plaques occur in the compressed area, involving the skin and skin tissue. It is more likely to occur on the palms, soles and buttocks and usually lasts 8 to 12 hours. Sometimes it may be accompanied by chills, headache, joint pain, and general discomfort. The mechanism of attack is related to kinins.