prurigo

Introduction

Introduction to pruritus Prurigo is a general term for a group of acute or chronic inflammatory skin diseases, which occurs in the pruritic skin disease of the extremities. Most of the skin lesions are isolated papules or nodules. After the infection, pigmentation is left, and local skin lesions are severely itchy. The course of the disease is chronic, sometimes unhealed for months or years, pruritus has different names, and there is no consistent classification. Due to different clinical manifestations, pruritus is classified as pediatric pruritus, common pruritus, nodular pruritus, pruritus of pregnancy and pruritus in summer. The cause of this disease is unknown. Most scholars believe that it is related to hypersensitivity reaction, and may also be related to neuropsychiatric factors and genetic allergies. Other factors such as insect bites, food or drug over-infection, gastrointestinal dysfunction, pregnancy and endocrine disorders Etc. also often has an impact. basic knowledge The proportion of illness: 30% Susceptible people: no special people Mode of infection: non-infectious Complications: skin disease pruritus

Cause

Cause of pruritus

Externally sensitizing contact, daylight (25%):

Some scholars believe that allergic contact, sunlight, food and drug allergies, in addition to digestive system dysfunction, lesion infection, malignant tumors in the body, neuropsychiatric factors may be related to the occurrence of this disease .

Genetics (20%):

It is generally believed to be related to allergic reactions. Some patients have a family history of allergies. Chinese medicine believes that this disease is caused by spleen deficiency and dampness, and the external sense of wind and evil is caused by fumigation of the skin, or liver qi stagnation, stagnation of heat, and complex wind and evil. Caused by skin.

Endocrine changes (30%):

Therefore, pediatric pruritus is associated with atopic dermatitis, and some have papular-like urticaria first, and pruritus is related to insect bites. Because of the pruritus of pregnancy, it is self-healing after delivery, so some people think that it is related to endocrine changes.

Prevention

Itching prevention

Because the pathogenic factors of this disease are more complicated, it is often difficult to affirm the cause of the disease, which brings certain difficulties to the treatment. It is best to find the cause, cure it, prevent insect bites, and correct the symptoms of gastrointestinal dysfunction such as diarrhea and constipation. Those who have lesions should be treated, pay attention to improve nutrition and health.

Complication

Itching complication Complications, skin disease, pruritus

Due to long-term friction and scratching, bleeding and blood stasis, the surrounding skin often has pigmentation and mossy changes, sometimes similar to coin-like eczema.

Symptom

Symptoms of pruritus Common symptoms Pediatric pruritus, itching, papules, acne nodules, herpes, herpes

1. Pediatric pruritus, also known as Hebra pruritus or early-onset pruritus, mild pruritus, mostly in childhood, skin lesions start mainly red papules, miliary to mung bean size, can also be wheal or papule-like urticaria-like rash, after Become an arcuate nodular papule or small nodule damage, due to scratching, blood stasis or eczema-like changes, the extremities of the extremities are common, but the back, head and face can occur, and the symptoms are severely itchy. After the rash subsides, there is pigmentation, and it can be repeated. A small number of patients continue to adulthood, and the axillary and inguinal lymph nodes can be swollen.

2. Prurigo Vugaris (Prurigo Simplex), also known as Prurigo Simplex, is more common in middle-aged men and women, the damage is a circular round pimples, mung bean to pea size, the number is variable, there are tiny blisters on the top of the pimples, but The blister is often scratched and not seen. The surface of the blister is left with serous scarring, and the damage appears in batches, causing severe itching. Due to long-term scratching, scratches, mossy and pigmentation may occur, and a few cases remain a bit. Scarred.

The rash occurs in the extremities and the torso, buttocks, etc., and the damage naturally disappears in a short period of time, but sometimes it recurs.

3. Prurigo nodularis (also known as Urticaria Perstans Verrucosa) damage from reddish or red pimples, quickly becoming a dome-shaped solid nodule, from peas to nail size Generally, it is grayish brown or reddish brown, which damages the surface keratinization, rough and scorpion-like. It has a firm feeling of touch, and it is violent and itchy. Due to long-term friction and scratching, bleeding and blood stasis appear, and the surrounding skin often has pigmentation. And mossy changes, sometimes similar to coin-like eczema.

Damage often occurs in the extremities, especially in the lateral extension of the calf. The back or other parts can also occur. The number is variable. The nodules have a tendency to align along the limbs. This disease is more common in adults, with women accounting for the majority, chronic After, it will not heal for a long time.

4. Pregnancy pruritus (Prurigo gestationis) often occurs in women in the second pregnancy, a small number of patients can also be seen in the first pregnancy of pregnant women, the damage occurred in the third to fourth month of pregnancy, or the last two months of pregnancy The rash is reddish papules, herpes or wheal-like damage. A few patients have similar damage to erythema multiforme. Symmetry is distributed in the trunk, buttocks, thighs and even the whole body. It is violent and itching. Traces, bloody and mossy changes, most patients with skin rash after childbirth naturally, a small number of patients can not immediately decline after delivery, for several months or years, pregnant women with severe rash can have stillbirth.

5. Summer Prurigo Some scholars believe that the disease is mild summer vesicular disease (hydroa aestivale) or acne vacciniforme (hydroa vacciniforme), which is a wheal-like papule, which can cause blisters and itching is severe, but No acne-like damage occurs, and scars are not left after the rash subsides, often occurring in adults.

Examine

Itching rash

Mainly for pathological biopsy: non-specific lichen-like tissue reaction, epidermal keratosis, epidermal hyperplasia, intercellular edema, basal cell liquefaction, perivascular cell infiltration and vasodilation, pigmentation incontinence were observed.

Occasionally, eosinophils in peripheral blood increased.

Diagnosis

Diagnosis of pruritus

diagnosis

According to the rash, the erythema is mostly erythema, papules, nodular damage, symmetrical arcing occurs, and the extremities are stretched to the side, especially the upper limbs. The rash is followed by pigmentation patches, with severe itching, chronic disease, and is not difficult to diagnose.

The pathological changes of the disease are non-specific chronic inflammation, hyperkeratosis and parakeratosis of the epidermis, hypertrophy of the spinous cell layer, edema in the epidermis, blisters in the superficial epidermis, mild edema in the dermis, and lymphocytic infiltration around the blood vessels. The pathological epidermis of nodular pruritus has obvious hyperkeratosis and acanthosis, papillary hyperplasia, superficial dermal tissue cells, and lymphocyte infiltration.

Differential diagnosis

1. Papular urticaria: The onset of the disease is seasonal, mostly in the summer and autumn. The rash is a prismatic wheal or a blister, with a short course and no lymphadenopathy.

2. Herpes-like dermatitis: rash of blister or bullous symmetry, symmetry occurs, most patients have gluten enteropathy, histopathological specific changes, direct immunofluorescence examination of the dermal papilla IgA and C3 particles Sinking.

3. Sacral lichen planus: The rash is a thickened plaque with a rough surface, with scaly scales on the surface, histopathology with lichen planus, and neurodermatitis.

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