Itchy skin in uremia is one of the most uncomfortable symptoms of uremic patients, which is annoying and seriously destroys the quality of life of patients and seriously affects the psychological condition of uremic patients, leading to boredom, mental depression and even suicidal tendencies in severe cases. According to statistics, its incidence is about 37%-90% in hemodialysis patients, 25%-70% in abdominal dialysis patients, and about 25%-59.3% in patients with chronic renal failure who are not on dialysis, with 20% of generalized itching and 30% of local itching.
The main manifestation is generalized and localized pruritus of varying degrees, with the forehead, back of the neck and forearm palms being the typical sites of occurrence. The itching can be paroxysmal, with varying durations, and there is a marked difference in the degree of itching between daytime and nighttime, often relieving itself and then recurring. The following lesions may also appear due to scratching.
1, simple moss, a localized mossy, consisting of isolated limited patches, about 2-10 cm in size, often appearing on the side of the forearm, scrotum, groin and anal perineum area.
2. Pruritic nodules, which are polymorphic brown nodules, often covered by scales, scabs and scratches.
3. Keratotic plaques, which are red or violet lesions, 3-12 mm in size, with typical central plugs, often appearing on the side of the body of the limb and on the palms of the hands and feet.
The causes of its occurrence may be related to the following factors.
1, reduced moisture content of the skin, dry disease or “dry skin” is one of the most common skin conditions in uremic patients. Dryness may indicate atrophy of the sebaceous or sweat glands, as well as a defect in their exocrine function, which causes itching.
Peripheral neuropathy is a common comorbidity in patients on maintenance hemodialysis, with an indescribable mosquito walking sensation, deep itching and tingling.
3.Increased ion concentration in the skin, many dialysis patients have hypercalcemia, hypomagnesemia, and hyperphosphatemia.
4. Parathyroid and secondary hyperparathyroidism. It has been reported that pruritus can be rapidly reduced after parathyroidectomy or after treatment with medication.
5. Elevated plasma histamine levels. Histamine is mainly secreted by skin columnar cells, basophils, platelets, and columnar cells of the peritoneum and bronchi, and is synthesized, stored, and cleared in the kidneys.
6, dialysis-related pruritus, the frequency and degree of uremic pruritus occurring after the start of dialysis is increased, dialysis increases the patient’s contact with pruritogenic substances, such as: heparin, sterile iodine, potassium permanganate, puncture needles containing nickel, sterile antiseptic, epoxy resin, formalin, ethylene oxide, etc
7. Possible immune reaction.
What are those treatment measures for uremic patients with itching symptoms? In general, because the cause of its occurrence is multifactorial, treatment can take comprehensive therapeutic measures so as to achieve relief of symptoms.
The first step is to improve the frequency and mode of dialysis, which includes: adequate dialysis (3 times/week, 5h/time): increasing effective dialysis can improve pruritus symptoms. It is well recognized that metabolite retention in uremic patients is associated with the development of pruritus; pruritus is treated with dialysis tandem with a resin perfuser, which can remove some of the medium and large molecules of toxins. Recently, it has been reported that blood perfusion can effectively reduce the concentration of histamine in the blood and stop itching; closed-circuit circulation before dialysis: 0.9% sodium chloride is used to pre-flush the vascular circuit before dialysis. Closed circuit for 10-20 min to clear the allergy caused by the retention of chemical disinfectant in the vascular pathway; magnesium-free dialysis solution: it has been reported that pruritus is related to serum magnesium value, and itching can be stopped with magnesium-free dialysis solution, but its effect is yet to be confirmed by further studies.
Secondly, patients’ serum calcium, phosphorus, PTH, B2 microglobulin levels were monitored and detected. If PTH is high, a low phosphorus diet should be strictly followed and phosphorus-lowering drugs should be applied, eaten with rice and mixed with rice to facilitate full absorption of phosphorus from food. After the calcium and phosphorus standards are reached, vitamin D3 should be added; Cinacalcet activates calcium receptors in the parathyroid glands, thus reducing the secretion of parathyroid hormone (PTH).
It regulates the behavior of parathyroid calcium receptors by enhancing the sensitivity of the receptors to calcium levels in the bloodstream, which can result in lowering levels of parathyroid hormone, calcium, phosphorus and calcium-phosphorus complexes; improving osteoporotic bone softening; reducing vascular calcification; reducing skin calcification and ulcers; and reducing parathyroid hyperplasia. Parathyroidectomy: After parathyroidectomy, the patient’s serum calcium values drop and the itching fades or is reduced, while itching will reappear when the blood calcium returns to normal.
Once again in terms of life care need to
(1) Keep the skin clean: bathe regularly, change clothes regularly, and bathe without irritating soap. If your body allows, take a warm water bath or sauna every week to eliminate itchy substances and wet the skin.
(2) Keep enough sleep: take sedative once a night, most patients report better sleep, the itchiness has also been alleviated.
(3) Keep the bowels open, 1-2 times a day, if the blood potassium is not high, to low protein diet, eat more coarse fiber vegetables.
(4) Topical corticosteroid creams such as DXM or urea creams of various antipruritic agents can be applied to the scratching area (5) Skin emulsions and moisturizers for dry skin can be used.
Measures that can be taken in terms of drug treatment include
(1) If necessary, calcium, procaine intravenous closure or lidocaine 100mg with 5% sugar water 100ml IV, Sormidor 1 tablet orally, alprazolam 0.4mg orally, any one of them according to individual adaptation.
(2) Apply erythropoietin to reduce pruritus and lower plasma histamine levels in patients with high plasma histamine levels.
(3) Oral loratadine and other antihistamines and calming hypnotics; the most commonly used oral medications. However, their anti-malarial effect is limited.
(4) Some specialist drugs can also be effective from time to time. Thalidomide can reduce peripheral itching irritation and block the vicious cycle of itching and scratching. Silva et al. reported: 29 cases of refractory uremic pruritus with thalidomide and placebo in a crossover double-blind efficacy observation, the total effective rate was 81%, that this drug is effective for intractable pruritus that other drug treatment is ineffective, the dosage of 100mg/d. Of course, thalidomide should pay attention to its side effects, common are dryness of the mucous membrane of the mouth and nose, dizziness, lethargy, high sleep, nausea, abdominal pain, constipation, facial swelling, facial erythema, allergic reactions and multiple neuritis, etc.
(5) Sex hormone therapy may be considered in elderly patients if necessary.
(6) Oral activated carbon: It has been reported that the patient took 6 grams of activated carbon and five-carbon sugar, and the itching symptoms disappeared after 8 weeks. The mechanism may be that activated carbon can absorb the itch-causing substances in the intestine.
(7) Extirpine: Extirpine has been used for pruritus associated with blocked xanthogranuloma and true erythrocytosis. It has been reported that the administration of 5 g of bilirubin twice a day can suppress the onset of pruritus. The effect may be related to its ability to remove some unknown organic acid that causes pruritus in uremia, but it causes side effects such as nausea and constipation and lasts for up to 3 days after discontinuation of the drug.
(8) Heparin: Some patients with pruritus due to allergy to porcine or bovine heparin can be switched to other types of heparin to remove this allergy-induced pruritus. It has also been reported that intravenous infusion of heparin 75-100 mg twice a day for 2-3 weeks can eliminate pruritus, and its effect can last for several days to weeks.
(9) Ergot Bromide: It is a dopamine receptor agonist and partial alpha-adrenergic blocker. It has been found that oral administration of 30 mg of ergot bromoxynil and 5 mg of static drip in dialysis can make the pruritus disappear, but the pruritus recurs 24-48 hours after stopping the drug, while oral administration of 30 mg day by day reduces or disappears the pruritus in most patients after 6 months. The effect is presumed to be related to the blockage of alpha-adrenergic activity.
(10) Meperidine: This is a mast cell stabilizer, the mechanism of action may be through blocking the formation of mast cell derivatives. There are reports of 5 patients taking 2-4 mg of meperidine for a total of 8 weeks, the symptoms were significantly reduced, and in 2 cases the effect lasted for 2 years.
(11) Naloxone: This is an opioid receptor blocking agent. The trial confirmed that 0
(12) Naloxone: It is an opioid receptor blocker.
(12) Neurontin: It is an extract made by filtration inoculation in rabbits after epidermal inflammation. Fifteen minutes after the start of hemodialysis, there is a significant increase in c3a in the blood causing itching, and neurotoxin can stop itching by inhibiting C3a activation. Steroids have been reported to significantly improve pruritus when other treatments for severe uremic pruritus fail.
There are also a number of other therapies
(1) Ultraviolet therapy: Many studies have shown that ultraviolet radiation is effective for pruritus uremicus. This may be due to the fact that UV-A reduces the activity of certain circulating itch-causing substances or activates vitamin D to reduce the concentration of phosphorus in the skin, thus stopping itching. Treatment with both UV-A and UV-B (wavelength 320-400 nm) has also been used, and the mechanism of action may be related to the reduction of higher vitamin levels in patients with uremic pruritus. It has also been reported that UV-A is effective but UV-B is ineffective, probably due to the high dose of UV-B that destroys cells and increases blood histamine levels.
(2) Superficial x-ray radiotherapy or local closure may be used for limited patients;
(3) Electroacupuncture stimulation: This is a modified Chinese method that can be used to treat pruritus and can lead to increased sleep time.