新人999如何治疗风疙瘩配图，仅供参考
Treatment# General measures
Initially it is helpful to explain to patients what urticaria is and that very often it is not due to ‘an allergy’. They may be reassured that in nearly all cases there is no serious underlying medical problem causing the rash; that safe,effective treatments are available and that the long-term prognosis is usually good. A patient information leaflet,such as that available from the British Association of Dermatologists,is helpful.
Next,if any obvious triggering factors have been identified from the history these should be eliminated,wherever possible. For example,specific food triggers should be excluded from the diet; treatment with aspirin,NSAIDS and codeine should be stopped; physical triggers such as coldand heat should be avoided whenever possible; and clinical thyroid disease or underlying infection treated. Anti-pruritic,cooling skin lotions such as calamine lotion or 1% menthol in aqueous cream may help to relieve itching.
The initial medical treatment for urticaria is a standard dose of a second-generation H1 anti-histamine. These drugs penetrate the blood–brain barrier to only a slight extent and so cause fewer central nervous system side effects than the older first-generation anti-histamines,although symptoms such as sedation and psychomotor impairment may still occur. Seven such anti-histamines are licensed for use in the United Kingdom: Cetirizine,desloratidine,fexofenadine,levocetirizine,loratidine and mizolastine,which are all given once a day,and acrivastine which is given three times a day,and may therefore be less effective and convenient to use. Cetirizine and levocetirizine and loratidine may have clinically useful ‘anti-inflammatory’ properties at therapeutic doses. Cetirizine may cause drowsiness in some patients and mizolastine is contra-indicated in patients with cardiac disease; prolonged Q-T interval; or severe liver disease. Dose reductions may be needed if there is renal impairment. Clinical response and tolerability may be better with one second-generation H1 anti-histamine than another,so if symptoms are not well controlled or the patient notices side effects with the first drug chosen,a second drug should be tried. Often,symptom control is improved if the dose of anti-histamine is increased to twice daily. This is above the licensed recommended dose; however,‘off-label’ dosages are recommended widely . A night-time dose of one of the older first-generation,sedating H1 anti-histamines,such as chlorphenamine or hydroxyzine,may help patients to sleep. Empirically,anti-histamine treatment is usually prescribed for 3–6 months (or longer if the patient has angioedema associated with the urticaria) and is tailed off gradually. Episodic urticaria may be treated with stat doses of anti-histamines as required.
If the urticaria remains unresponsive to high-dose H1 anti-histamines,H2 anti-histamine treatment,at standard dosage,may be added. This is an off-licence use of these drugs,but there is evidence that combined H1 and H2 anti-histamine treatment gives better symptom control than H1 anti-histamine treatment alone . Unlike cimetidine,ranitidine does not inhibit oxidative hepatic drug metabolism and so has less potential to cause drug interactions.
In patients with very severe acute urticaria,associated possibly with angioedema or systemic symptoms,a short course of oral steroids is indicated. Dose and duration of the treatment is determined by the patients weight and clinical response. Prolonged courses of oral steroids for chronic urticaria should be avoided whenever possible,and if long-term steroid treatment is considered necessary,the patient should be followed-up regularly and prescribed prophylactic treatment against steroid-induced osteoporosis at an early stage . Oral steroids may be needed for urticarial vasculitis (see below) or severe delayed pressure urticaria.
# Dietary interventions
An objective trial of a low salicylate diet may be indicated in patients who give a clear history of having developed more severe urticaria,or even angioedema or bronchospasm,after taking aspirin or NSAIDs and,particularly,if the patient also responds to LTRA treatment . It is important to explain to the patient that the diet should not become more troublesome than the urticarial symptoms themselves and it may be simpler for patients to take a regular dose of an anti-histamine,rather than continue on a strict exclusion diet.
In children,an objective trial of a low E numbers diet may be helpful,especially if the clinical history suggests that episodes of urticaria may be related to ingestion of foods which are high in E numbers.
# Patients with severe urticaria unresponsive to standard treatments
In a very small number of patients,severe,debilitating urticaria,associated possibly with airway angioedema,bronchospasm and hypotension,persists despite treatment with high-dose H1 anti-histamines; H2 anti-histamines and/or LTRA; corticosteroids; and,perhaps,dietary interventions. These patients usually have autoimmune urticaria and cyclosporin treatment has proved effective in about 65% of such patients in a randomized double-blind study . Longer courses of cyclosporin may give a lengthier clinical response ; however,the optimum dose and length of treatment have not yet been established. Tacrolimus and mycophenolate mofetil have also been effective in open-label studies. Results of intravenous immunoglobulin treatment in small numbers of patients have been variable . The current recommendation from the clinical guidelines for the use of intravenous immunoglobulin is that intravenous immunoglobulin should not be used unless all other therapies have failed. If patients require immunomodulating therapies,referral to a specialist centre is recommended.","department":"
