- blood tests are unnecessary for mild ordinary urticaria in patients responding to antihistamines (1)
- the choice of investigations should be guided by the clinical presentation (1)
- treatment of cause if identified
- general measures: (2)
- avoidance of triggers if known e.g. overheating, stress, alcohol, drugs
- dietary modification may be helpful - avoid foods containing salicylate, preservatives or tartrazine
- use of a cooling antipruritic lotion - calamine or 1% menthol in aqueous cream
- clear written information sheets for patients
- pharmacological measures:
- antihistamines:
- anti-H1 group of anti-histamines - eg. cetirizine, loratadine, terfenadine, astemizole - have significant anti-itch qualities with minimal sedation
- note that terfenadine and astemizole can cause cardiac QT prolongation and tachyarrythmias. These drugs should not be used in combination or with other drugs known to lengthen the QT interval e.g. amiodarone, tricyclic antidepressants. Also there is a theoretical interaction between terfenadine and grapefruit juice
- currently there are a number of non-sedating H1 antihistamines licensed for the treatment of urticaria in the U.K. These include cetirizine, desloratadine, fexofenadine, levocetirizine, loratadine, mizolastine (all taken once daily) and acrivastine (taken three times a day) (3). No single antihistamine has shown itself to be superior for chronic spontaneous urticaria. (4)
- the addition of a sedating antihistamine is helpful if sleep is disturbed by symptom
- in some cases a combination of H1- and H2 receptor antagonists (e.g. cimetidine) may be used. H2 antagonists reduce vaso-permeability and vasodilatation (1)
- a H2-antihistamine administered concurrently with an H1-antihistamine may modestly enhance relief of itching and wheal formation in some patients with urticaria refractory to treatment with an H1-antihistamine alone. However the available evidence does not justify the routine addition of H2-antihistamine treatment to H1-antihistamine treatment (2)
- although antihistamines are not proven as a teratogenic drug it should be avoided during pregnancy especially during the first trimester (3)
- chlorphenamine is the recommended drug in controlling urticaria or pruritus during pregnancy (3)
- anti-leukotrienes
- taken together with a H1 antihistamine in poorly controlled urticaria (3)
- not useful as a monotherapy
- montelukast is the drug of choice (1)
- corticosteroids
- systemic steroids are not routinely used in the management of chronic urticaria.
- however in some cases may be recommended as a short course for non-responders to antihistamines (e.g. prednisolone 40 mg daily for 3-5 days in an adult)(1,3)
- systemic steroids may be required in delayed-pressure urticaria and to control urticarial vasculitis when a course of three to four weeks in tapering dose will be required
- long-term administration should be avoided in chronic urticaria (3)
- epinephrine
- intramuscular epinephrine can be used in anaphylaxis and in severe laryngeal angio-oedema (3)
- immunomodulating therapy
- ciclosporin has been useful in resistant chronic urticaria
- plasmaphoresis, intravenous immunoglobulin, and oral tacrolimus may be used in severe resistant autoimmune urticaria (1)
- omalizumab is effective in 80% of cases but requires monthly injections and relapse is common when it is stopped. The National Institute for Health and Care Excellence (NICE) recommends omalizumab as an add-on treatment for refractory severe chronic spontaneous urticaria in adults and young people aged 12 years and over (5)
- topical corticosteroids and topical antihistamines are not recommended in the management of urticaria (1)
- emergency treatment of angioedema - 0.5-1.0 ml adrenaline 0.1% IM, 10 mg chlorphenamine (piriton) SC/IM, 100 mg hydrocortisone IV; laryngeal intubation
- a patient should be referred an immunologist or dermatologist when there is:
- urticaria with angio-oedema not involving the airway
- food or latex allergy causing severe acute urticaria
- chronic persistent urticaria (usually lasting beyond 6 weeks) which is troublesome despite the use of antihistamines and avoidance of known trigger factors
- vasculitic urticaria: suspect if lesions are painful and persistent (2)
Reference:
1. Zuberbier T, Abdul Latiff AH, Abuzakouk M, et al. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022 Mar;77(3):734-66.
2. BSACI guideline for the management of chronic urticaria and angioedema. British Society for Allergy and Clinical Immunology (Feb 2015)
3. BNF. April 2024.
4. Sharma M, Bennett C, Cohen SN, et al. H1-antihistamines for chronic spontaneous urticaria. Cochrane Database Syst Rev. 2014 Nov 14
5. Omalizumab for previously treated chronic spontaneous urticaria. NICE Technology Appraisal Guidance, June 2015