pruritus
Introduction
Introduction to pruritus Cutaneous pruritus (cutaneous pruritus) refers to a clinically abnormal skin disease with no primary lesions and pruritus. In the course of sputum, secondary skin damage such as scratches, blood stasis, etc. may occur due to scratching. According to the extent or location of skin itching, it can be divided into two categories: limited and generalized. basic knowledge The proportion of illness: 1% Susceptible people: no special people Mode of infection: non-infectious Complications: Eczema
Cause
Cause of pruritus
Body factor (35%):
Including systemic diseases such as endocrine diseases (diabetes, hyperthyroidism, carcinoid syndrome, etc.), hepatobiliary diseases (primary biliary cirrhosis, biliary obstruction, etc.), kidney disease (chronic renal failure, chronic hemodialysis), blood Disease (iron deficiency anemia, polycythemia vera, etc.), malignant tumors (lymphoma, leukemia, etc.), neurological diseases (myelopathy, paralytic dementia, etc.), infectious diseases (AIDS, tuberculosis, filariasis, etc.) Wait.
Physical and chemical factors (30%):
It is related to physical (heat, cold, etc.), mechanical (friction, etc.), chemical stimulation (acid and alkali, etc.), food (spicy food), drugs (belladonna, cimetidine, chloroquine, etc.).
Other factors (35%):
Defects in autoimmunity, resulting in low resistance, allergic constitution, pathogenic bacteria cause skin disease through direct contact or indirect contact.
Pathogenesis
Due to systemic diseases, physical, mechanical, chemical stimuli, food, drugs and other factors force nerve or mental factors to participate in the disease, the body produces mediators related to pruritus (such as histamine, kinin, prostaglandins, substance P, opioids) Etc.) causes itching of the body.
Prevention
Skin pruritus prevention
1. Find the cause and remove it.
2. Avoid various stimulating factors, such as excessive scratching, boiling water, applying detergent, drinking alcohol, and eating spicy food.
3. Early diagnosis and early treatment.
Complication
Pediatric pruritus complications Complications eczema
Itching pruritus is more common in sweaty hands and feet, patients with sweat herpes, itching of the external auditory canal is caused by excessive mechanical stimulation such as sputum or ear spoon, often followed by eczema or purulent infection.
Symptom
Symptoms of pruritus Common symptoms Skin itching itchy benign reaction changes scrotal itching anal itching calf itching dry pregnancy pruritus pediatric hip itching thigh medial itching thigh long red
1. Paroxysmal severe itching: Itching often occurs at regular intervals, generally with mental changes, before going to sleep, temperature changes, drinking and eating spicy foods are most likely to cause, once attacked, often unbearable, must be strongly scratched, sometimes even with the help of instruments Scratching, until the skin breaks blood, feels pain, can stop.
2. No primary damage: due to frequent scratching, the skin often has scratches, blood stasis, pigmentation, eczema, moss and other secondary damage.
3. The incidence of this disease varies with age and season, generally more common in the elderly (senile pruritus), winter and summer prone (winter pruritus, summer pruritus), in winter, spring can be more In the summer, it is light in winter.
4. P.universalis: It usually starts from one place, gradually spreads, and even spreads throughout the body. It is more common in the elderly. In addition to the atrophy and dryness of the aged skin, it is easy to occur, visceral cancer, liver disease. Systemic diseases such as diabetes are easily associated with this disease.
5. P.localis: Itching is limited to a certain part, and it can be invaded at the same time, mostly related to local factors, generally the vulva, anus, head, calf, palmar, external auditory canal, etc. More common.
(1) genital pruritus: both men and women can occur, more common in middle-aged, males often in the scrotum (scrotic pruritus P. scroti) can be extended to the base of the penis, women more common in the labia majora (Female pruritus P.vulvae) And its vicinity, genital itching is changed to chronic due to improper treatment or abuse of irritating drugs, the skin is characterized by infiltration and hypertrophy, easy to be followed by eczema, itching is severe, the course of disease is prolonged, and it has not healed for many years.
(2) Anal pruritus (P.ani): Chinese medicine refers to the itch of the valley, which is thought to be related to the dampness of the large intestine and the accumulation of insects. Itching is generally confined to the anus and its surrounding skin. It is more common in middle-aged men and suffering from tsutsugamushi disease. Children, anal itching increased at night, can find mites and find mites eggs: (higher positive detection rate at night), adults are caused by hemorrhoids, anal fissure, etc., a few patients can not find obvious reasons Often, due to repeated scratching, local moist, so that the perianal skin appears infiltration, erosion, wrinkle hypertrophy, radial splitting, eczema or mossy changes.
(3) scalp pruritus (P. capitis): more common in patients with scalp seborrheic, especially at dawn when the scalp is itchy, often secondary to eczema, folliculitis or phlegm.
(4) P. cruris: mainly found in calf varicose veins, ichthyosis or dry skin, cold stimulation, ligaments and leggings are often the cause of tension.
Examine
Examination of pruritus
Auxiliary inspection
1. Local examination: skin lesion examination, skin disease examination.
2. Etiology check: If the diagnosis is unknown, there are visceral diseases, and it is necessary to check the specific cause when the visceral tumor needs to be excluded.
Diagnosis
Diagnosis and diagnosis of pruritus
According to the initial itching, only the original itching, and no primary skin lesions, while excluding eczema, neurodermatitis, rickets, hemorrhoids and other diseases, can make the diagnosis of the disease, after the diagnosis, to further judge the systemic (or Generalized) is still limited, and it is more important to find the cause of itching. For this reason, a comprehensive physical examination and necessary laboratory tests are needed for more effective treatment.
Skin pruritus is associated with eczema, neurodermatitis, rickets, hemorrhoids and other diseases. It has more intense itching, but the most basic difference is that the former has no primary skin, while the latter has, and rickets can find adult worms. Or eggs; acne is more common in some special parts such as finger joints, characteristic tunnels, acne nodules, collective infection, can find mites or eggs.
