Autoimmune Theories of Chronic Spontaneous Urticaria
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They can be a useful long-term alternative to using corticosteroid tablets because they don't carry the same risk of causing wide-ranging side effects. An increased dose may be recommended if your symptoms don't respond to treatment. Increasing the dose can often help control symptoms that previously didn't respond to treatment.
In this subset of patients, IgG anti-FcεR1α pathologically induced histamine release irrespective of the degree of IgE sensitization of the basophils. As proof of concept, histamine release was effectively neutralized in a concentration-dependent manner by preincubating donor basophils with soluble fragment of FcεR1α prior to the addition of purified IgG from sera of patients with CSU. Traditionally we add “stomach-ulcer treatment” medication such as Cimetidine and Ranitidine which are known to also dampen down histamine release. Ranitidine containing a chemical NDMA has been implicated in a recent cancer scare. Occasionally we need to add sedating antihistamines such as Chlorphenamine or Hydroxyzine at night to get urticaria control.
While cellular signaling defects may account for some cases of CSU, the autoimmune theory is the more widely accepted hypothesis to explain the inappropriate activation of mast cells and basophils in patients with chronic spontaneous urticaria. In a sentinel study conducted by Grattan et al., 12 patients with chronic urticaria were subjected to intradermal autologous serum injection . Seven of the 12 subjects mounted a positive wheal-and-flare reaction to this test, and fewer of these patients described a history of disease exacerbation with application of pressure when compared to patients with a negative injection test. This suggested that these patients with a positive result were less likely to have an inducible urticarial syndrome.
If the itchiness is causing you discomfort, antihistamines can help. Antihistamines are available over the counter at pharmacies – speak to your pharmacist for advice. Your GP will usually be able to diagnose urticaria by examining the rash.
When renal crisis is suspected, blood pressure should be carefully controlled. Kaposi's sarcoma has been reported to occur in patients receiving corticosteroid therapy. Discontinuation of corticosteroids may result in clinical remission. Adrenal cortical atrophy develops during prolonged therapy and may persist for years after stopping treatment. Withdrawal of corticosteroids after prolonged therapy must therefore always be gradual to avoid acute adrenal insufficiency, being tapered off over weeks or months according to the dose and duration of treatment. During prolonged therapy any intercurrent illness, trauma or surgical procedure will require a temporary increase in dosage; if corticosteroids have been stopped following prolonged therapy they may need to be temporarily re-introduced.
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