Section I. Neurodermatitis
Neurodermatitis, also known as chronic simple moss, is a chronic inflammatory disease characterized by mossy skin and intense itching. It is generally believed that the occurrence of this disease may be due to cortical inhibition and excitation dysfunction, mental tension, anxiety, depression, local stimulation (such as friction, sun expectation, sweating), as well as indigestion, alcohol consumption, eating spicy, etc. can trigger or aggravate the disease.
Etiology]
The cause of the disease is still unclear, it is generally believed that the dysfunction of the nervous system, cortical excitation and inhibition process imbalance related to the causes of neurodermatitis are mainly the following.
1, mental factors: currently considered to be the main trigger for the occurrence of the disease, mood swings, excessive mental tension, anxiety, sudden changes in the living environment, etc. can make the disease aggravated and repeated.
2, gastrointestinal tract dysfunction, endocrine system function abnormalities, chronic lesion infection in the body and allergy, may also become causative factors.
3, local stimulation: such as friction caused by hard collar, chemical stimulation, insect bites, sunlight exposure, scratching, etc., can induce the occurrence of the disease.
Histopathology: dense orthotypic hyperkeratosis, occasionally incomplete keratinization, spiny layer hypertrophy, epidermal protrusions uniformly prolonged, intracellular and intercellular edema in the spiny layer, increased pigment granules in the basal layer, thickened collagen fibers in the dermal papillae, vertical arrangement, scattered infiltration of lymphocytes around the superficial blood vessels, epidermal hyperkeratosis, spiny layer hypertrophy, epidermal protrusions prolonged, may be accompanied by mild sponge formation, capillary hyperplasia in the dermis, vascular There is lymphocyte infiltration around the dermis, or dermal fibroblast proliferation and fibrosis can be seen.
Clinical manifestations
1. The rash is usually found on the neck, extremities and lumbar region, N fossa, vulva;
2, self-conscious itching, chronic course, can be recurrent or persistent;
3, there is often local itching, after repeated scratching and rubbing, local corn-like green bean-sized round or polygonal flat papules, skin-colored, light red or light brown, slightly shiny, and later the number of rashes increased and fused into pieces, becoming a typical moss-like lesions, lesions of different sizes and shapes, surrounded by a small number of scattered flat papules;
4. Clinically, it is divided into limited type and disseminated type. The former is more common.
(1) limited neurodermatitis: more than 90% of them are found on the neck, followed by the elbow, sacrum, eyelid, N fossa, etc. Firstly, they feel local itching, and then appear clusters of normal skin color or light brown, light red polygonal flat papules, slightly shiny, covered with a small amount of chaffy scales, and then the papules fuse with each other to form patches, and the skin is gradually thickened due to itching and scratching, forming mossy lesions with clear boundaries. Scratch marks and blood crusts are common around the affected lesions.
(2) Diffuse neurodermatitis: the lesions are similar to limited neurodermatitis, but widely distributed, involving the head, limbs and trunk, etc., itchy, especially at night, affecting sleep, the disease is chronic, prone to recurrence, due to frequent scratching can be secondary to eczema-like changes or secondary infections occurring folliculitis, boils, etc.
Diagnosis
1, the disease is common in young and middle-aged people, with intense itching first, followed by skin lesions.
2, the rash is flat papules, moss-like changes, no exudation.
3. The rash is usually found on the neck, extremities, lumbosacral region, N fossa, and vulva.
4. The course of the disease is chronic and often recurrent.
Treatment
I. Treatment principles
1, remove the possible causes, such as mood swings, or neurasthenia can be given to sleep sedative drugs.
2, avoid stimulation, such as repeated local scratching, hot water scalding, detergent use and other adverse stimuli. Avoid stimulating diet such as wine, strong tea, coffee and spicy food.
3.Anti-itch, antihistamines, intravenous and local closed treatment, topical corticosteroid ointment, hard cream and tar preparations can be given.
4.Physical therapy, including superficial X-ray irradiation, isotope 32 phosphorus, 90 strontium dressing, liquid nitrogen freezing, radium, magnetic therapy, wax therapy, mineral bath and photochemotherapy.
Second, the principles of drug use
1, general patients can be given one to two antihistamines, intravenous and local closed treatment, topical corticosteroid ointment, hard cream and consular tar and other preparations to stop itching.
2, generalized or severe patients can be given oral corticosteroids or physical therapy.
Prevention
1, avoid emotional impulse, avoid scratching with hands or hot water scalding.
2, should not wear hard underwear, so as not to stimulate the skin.
3, avoid alcohol and tobacco, chili and other irritating food, eat more light food and fruit
Section II pruritus
Pruritus is a skin sensation (often uncomfortable) that causes scratching, rubbing, gouging, and in some extreme cases can even be seen to make the skin mutilate to get relief. Pruritus/pruritus (the two terms can be used interchangeably) is the most common symptom in patients with dermatological conditions, and itching is present in almost all inflammatory skin conditions.
Pruritus is a skin disease with only pruritus without primary lesions and is common clinically, especially in the elderly. It can be divided into two types: generalized and limited pruritus.
[Etiology].
The etiology of this disease is complex, systemic pruritus is mostly related to some chronic visceral diseases, local bad stimulation is often the external cause of triggering and aggravating the disease, but also closely related to limited pruritus.
I. Internal causes
1, visceral diseases Stomach, intestines, liver, kidneys and other visceral organs occur functional or organic diseases; certain tumors such as leukemia, lymphosarcoma, malignant lymphoma, etc.
2, neuropsychiatric system disorders, cerebral arteriosclerosis, neurasthenia, neurosis patients have some kind of hallucinations, think there are bugs in the skin and feel itchy, some develop the habit of scratching.
3, endocrine disorders, pregnancy, menstrual disorders or ovarian disease often cause pruritus of the female genitalia. Pruritus in the elderly may be related to lower levels of sex hormones in the body. Patients with thyroid disease can have pruritus.
4, in addition to the above, focal infections, drugs, diet (alcoholism), food allergies and parasitic or fungal infections can cause generalized or restricted pruritus.
Second, external causes
1, temperature changes, winter pruritus and summer pruritus patients are extremely sensitive to changes in temperature. Bedding too hot, sudden heat or cold may cause the onset of pruritus.
2, mechanical friction or physical and chemical factors of stimulation can cause local itching. For example, some people are sensitive to wool, some alkaline soap, wearing chemical fiber woolen fabrics.
3.In addition, disinfectants, insecticides, deodorants, dyes and other irritants can make the local skin itchy.
Clinical manifestations
1.Limited pruritus: clinically most common in the anus, female pubic and scrotum and other parts
(1) anal pruritus: the most common limited pruritus, mostly in middle-aged men, often confined to the perianal area, sometimes spreading forward to the scrotum, backward to both sides of the buttock groove, women can also develop, children with pinworm disease can also cause anal pruritus, the skin around the anus is often grayish white or pale white impregnation, anal crease hypertrophy, due to scratching and the occurrence of radiation chaps; sometimes secondary infection; After a long time, the skin around the anus thickens and becomes mossy, and pigmentation can also occur.
(2) Female pruritus: mainly occurs in the labia majora and labia minora, and also in the pubic frenulum and clitoris. Due to itching, the skin of the vulva is thickened and impregnated with gray, and the clitoris and vaginal mucosa are red, swollen and eroded.
(3) scrotal pruritus: itching occurs in the scrotum, but can also spread to the penis or anus, due to constant scratching, scrotal skin hypertrophy, and pigmentation changes, or moss-like changes, some patients can see vesicles, oozing and crusting and eczema-like changes.
Some patients feel itchy all over the body and need to brush the skin with iron brushes or wash with hot water until the skin bleeds and feels pain and burning, then the itchiness is temporarily reduced, often with heavy itching in the evening. Due to the intense itching and constant scratching, scratch marks, blood scabs, or striped scratches can appear, and sometimes there are eczema-like changes, mossy changes or pigmentation, and the scratched skin is also prone to infection and boils or folliculitis.
3, pruritus in the elderly: occurs in the elderly tend to be the most itchy trunk; winter pruritus appears in the cold season, induced by the cold, the patient is often off to sleep, began to feel intense itching on the inside of the front side of the femur, calves and other parts, the more you scratch, and the more itchy the more you scratch until local bleeding.
4, systemic disease-related itching
(1) Uremic pruritus: often systemic, refractory, and severe symptoms, with dialysis-associated pruritus can be episodic, milder, or confined to the dialysis catheter site, face, or legs, with an incidence of 10% to 40%. Complications such as chronic lichen simplex and nodular itch rash may occur. Many patients are associated with dryness, and appropriate systemic skin care and improvement of dry skin with emollients is the most basic treatment.
(2) Cholestasis-associated pruritus: The typical manifestation of pruritus is widespread pruritus, with the special feature that pruritus may involve the palms and plantars of the hands and feet and may be associated with jaundice. Treatment focuses on the removal of possible pruritogen in the circulation, with endogenous opioid receptor antagonists (naltrexone, nalmefene, naloxone) as the treatment of choice, followed by the liver enzyme inducer rifampicin.
(3) Hematologic-associated pruritus: common true erythroblastosis, Hodgkin’s disease, T-lymphocytoma, leukemia, multiple myeloma, Waldenstrom’s macroglobulinemia, and systemic mastocytic hyperplasia. More than 1/3 of patients with true erythroblastosis have pruritus, often caused by temperature changes or occurring minutes after bathing.
(4) Endocrine disease-related pruritus: diabetic pruritus is more often confined to the perianal and external genital areas and can generalize throughout the body. Hyperthyroidism can be associated with pruritus and may be related to increased blood flow to the skin and persistent elevated skin temperature. Increased parathyroid hormone secondary to renal disease plays a role in uremic pruritus. Pruritus occurs in patients with primary hypoparathyroidism and may be associated with dry skin and cutaneous Candida infection. Pruritus and chronic urticaria may also be associated with autoimmune thyroiditis and autoantibodies against certain thyroid components.
(5) Pregnancy-associated pruritus: generally intense pruritus in the abdomen, which may extend to the thighs, chest, upper extremities and buttocks, and is easily combined with itchy rash and folliculitis in the second trimester and urticaria in the third trimester.
(6) Malignancy-associated pruritus: In patients with lymphoma and advanced malignancy, malignancy-associated pruritus is common and often causes intractable generalized itchy skin. Chemotherapeutic drugs and radiotherapy can also cause pruritus, but this pruritus is usually self-limiting. So far, the best treatment for this malignancy-associated itch is paroxetine.
(7) HIV-associated pruritus: Pruritus is an early symptom of AIDS, and patients can have several pruritic skin conditions or systemic diseases occurring simultaneously. Pruritus can also be an early primary symptom of HIV infection. Eosinophilic folliculitis with intense pruritus occurs in HIV-positive patients with a total CD4+ T-cell count of less than 300/μl, and its occurrence is associated with elevated serum IgE and can also occur suddenly after antiretroviral therapy.
5. Neurogenic pruritus: stroke, multiple sclerosis, brain tumors, and brain abscesses can have sudden onset, unilateral, persistent pruritus, sensory abnormalities, hyperalgesia, or pain, and usually sensory abnormalities are more common than pruritus in these patients. The affected area often has hyperpigmentation and/or scratch marks. Application of capsaicin ointment that depletes axonal substance P is a safe and effective treatment for localized neurogenic pain and neurogenic pruritus.
6. Parasitic paranoia: a rare psychosomatic disorder that occurs in young people and middle-aged and older women. Patients stubbornly believe that they are infected with parasites. The patient scratches the skin to remove the infestation. Skin ants are often the first symptom described by the patient as a crawling, biting or stinging sensation. Some patients also describe to the physician in detail how the parasite infection occurred, how the parasite multiplied in the body and its life history. Patients often try multiple methods to eliminate the non-existent parasite, sometimes moving several times to get away from the parasite, and avoiding social interaction for fear of transmitting it to others. Some patients often provide dander, lint, scraps of paper or other specimens to confirm the presence of the parasite, a characteristic behavior known as the “matchbox sign” (i.e., patients often bring in matchbox specimens). Patients with this disorder may have skin lesions, mainly in the form of mild epidermal peeling, nodular itchy rashes or visible ulcers, which are artificially caused by the patient’s attempts to dig out the parasite. Parasitic paranoia is usually diagnosed by history alone, but a detailed dermatologic examination must be performed to rule out a true parasitic infection or other skin disease. Other psychological factors such as anxiety, depression, and severe psychopathy can cause pruritus.
Examination and diagnosis
1.Detailed medical history.
2.Check the skin mucosa and its appendages carefully and comprehensively to assess primary and secondary damage, distribution status, dryness of the skin and skin signs of systemic diseases.
3. Evaluation of patients with unexplained generalized pruritus may require laboratory tests. These include blood tests, tests of internal organ functions and diseases such as liver and kidney and other relevant tests.
4.According to the clinical manifestations of only pruritus without primary lesions, secondary lesions may appear due to scratching; pruritus varies in severity, often worsens paroxysmally, and is related to emotions, climate, diet and other factors; some patients with recurrent episodes may show some symptoms of neurological weakness; limited pruritus can be diagnosed mostly in the anus, scrotum and female genitalia.
【Treatment】
A. Treatment principles
1, clear etiology targeted treatment. Exclude visceral diseases related to pruritus and treat related diseases.
2, if the cause is unknown, cooling treatment can be used; control external factors that can aggravate skin itching, such as scratching, hot water scalding, irritating diet, etc.; dry skin appropriate application of moisturizers.
3, internal antihistamines and sedative-hypnotics.
4.Limited patients can be treated with superficial X-ray radiotherapy or local closure. Severe cases can be closed with intravenous calcium injection and procaine.
5. Topical corticosteroid cream or antipruritic agent. Older patients can be treated with sex hormones.
Topical antipruritic treatment
Topical anti-itch drugs include capsaicin ointment, 1% doxepin cream, 1% menthol, salicylic acid, tacrolimus and pimecrolimus. Topical glucocorticoids can reduce the itching caused by inflammatory skin diseases; it is not strictly an anti-itch agent.
Third, systemic anti-itch drugs
1, antihistamines: H1 receptor antagonists are commonly used, and are currently divided into first-generation and second-generation antihistamines. The first generation of antihistamines have a short half-life, requiring 3 times / d administration, easy to produce central inhibition, in addition to the treatment of severe itching, but also to reduce the associated anxiety, the representative drugs chlorpheniramine, benadryl, etc.. Second-generation antihistamines have a long half-life and can be administered once/d. They do not cross the blood-brain barrier, have a low incidence of central inhibition, and are suitable for daytime use, with cetirizine, loratadine, and imipramine as representative drugs. Pruritus induced by histamine is only mediated through H1 receptors, and anti-H2 receptor antagonists are ineffective in treating pruritus.
2. Inhibition of itch transmission in the center: μ-opioid receptor antagonists such as naloxone and naltrexone have been used to treat pruritus associated with cholestasis, uremia, and skin diseases. Κ-opioid receptor agonists (e.g., nalfurafine) also inhibit μ-opioid receptor effects and can treat severe pruritus. Butorphanol (butorphanol) is an opioid receptor agonist-antagonist analgesic with both Κ-opioid receptor agonist activity and μ-opioid receptor antagonist activity to suppress itching.
3, reduce the central sensation of itching: oral antidepressants such as mirtazapine can reduce itching in some patients. It can be used to treat nocturnal pruritus, and paroxetine can significantly reduce itching.
4. Blockage of nerve afferent pathways: thalidomide has an anti-itch effect on some skin conditions such as itchy nodules, eczema and senile pruritus. Gabapentin is an effective antipruritic drug, especially for pruritus of the brachio-radial junction, pruritus caused by multiple sclerosis and neuropathic pruritus. It modifies the sensation and itching associated with nerve damage.
5. Immunosuppressive/anti-inflammatory drugs: Skin conditions requiring systemic use of glucocorticoids include severe dermatoses, maculopapular dermatoses, vasculitis, autoimmune/connective tissue diseases, and neutrophilic dermatoses. Other drugs include azathioprine, morte-macrolimus, cyclosporine, tacrolimus, etc.