ABSTRACT
The treatment of chronic urticaria, as with virtually all other types of urticaria, begins with antihistamines as described in the preceding chapter. The amount and type used depend on the severity of urticaria and can be as simple as employing one of the second-generation antihistamines such as fexofenidine (1,2) deslora tidine (3), cetirazine (4,7), or high dosages of sedating antihistamines such as hydroxazine (50 mg four times daily) or a comparable dosage of diphenhydramine or doxepin (8). The latter agents are particularly useful for treatment of patients with severe disease in whom the nonsedating antihistamines provide only minimal relief. Their efficacy may rela te to properties other than blockade of H I-receptors such as effects of mast cell and basophil degranulation (5,6) or influx of cells [CD4(+) lymphocytes, monocytes, eosinophils and neutrophils] characteristic of chronic urticaria and delayed pressure urticaria (6). Somewhat greater antihistamine effect may be observed upon addition of an Hrreceptor antagonist because approximately 15% of cutaneous venule histamine receptors are of this subtype (7-9). Blockade of the H I-receptors is, however, required to observe any effect. Hrreceptor antagonists also are useful if corticosteroid is required to control severe chronic urticaria and
angioedema, since these agents provide protection against the consequences of steroid-induced hyperacidity. This chapter will deal primarily with agents other than antihistaminics and will report on studies demonstrating efficacy and comment on the utility (or Jack thereof) of modalities that require further investigation.
