Urticaria: Treatment, symptoms, advice and help
Urticaria refers to an area of focal dermal oedema secondary to a transient increase in capillary permeability producing wheals and itching.
Signs & symptoms of urticaria: Diagnosis
Wheals (raised areas surrounded by a red base) from urticaria can appear anywhere on the surface of the skin, often accompanied by itching. < 6 weeks (acute urticaria).If it lasts for < 6 weeks it is called acute urticaria and > 6 weeks (chronic urticaria).If individual wheal lasts for < 24 hrs it is called urticaria and > 24 hrs is called urticarial vasculitis.
Causes and prevention of urticaria
Allergens (in foods, inhalants and injections), drugs, contact with animal saliva, latex, physical stimuli (e.g. heat, cold, pressure, sun, water),infections (e.g. viral hepatitis, infectious mononucleosis, HIV infection), autoimmune conditions (e.g. systemic lupus erythematosus, pregnancy intestinal parasites) Urticarial Vasculitis may be caused by Hepatitis B or systemic lupus erythematosus.
On certain body sites such as the lips or hands the oedema spreads and is traditionally referred to as angioedema. The swelling lasts less than 24 hours. Acute urticaria may be associated with angioedema of the lips, face, throat and rarely, wheezing, abdominal pain, headaches and even anaphylaxis.
Certain investigations may be needed to identify the probable cause. C1 esterase inhibitor may be quantitatively reduced in hereditary angioedema. A skin biopsy may be helpful in urticarial vasculitis is suspected. Non-sedative antihistamines such as loratadine or dexofenadine, or antihistamines such as cetrizine, are effective for one-third of patients with chronic urticaria, one-third show moderate benefit, whilst the results in the remaining third are minimal. If a patient fails to respond to one of these agents after 2 weeks of therapy adding in an H2-blocker such as cimetidine or ranitidine may help. A number of other agents have been used, including mast cell stabilizers and leukotriene inhibitors and systemic corticosteroids. Urticaria may be precipitated by aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) and it is advisable to suggest alternatives such as paracetamol.