ABSTRACT
BACKGROUND: The use of herbal supplements is common, yet little is known about their pharmacologic properties. The purpose of this study was to assess the effects of 23 commonly used herbal supplements on histamine skin prick testing (SPT). METHODS: Fifteen healthy volunteers participated in a double-blind, placebo-controlled, single-dose, crossover study. Wheal and flare responses to SPT with histamine phosphate (1 mg/ml) were measured before and 4 h after administration of each of the 23 popular herbal supplements, fexofenadine (60 mg) and placebo. Wheal and flare areas were recorded with tracings performed 10 min after the prick test and measured with a PC-digitizer using stereometric software. RESULTS: Fexofenadine significantly suppressed the wheal (P < 0.001) and flare (P = 0.02) areas compared with placebo. None of the herbal supplements caused significant suppression of the wheal and flare areas compared with placebo (P > 0.10). CONCLUSION: When taken in single-doses, the popular herbal supplements tested did not significantly affect the histamine skin response. Therefore, it seems unnecessary for clinicians to ask patients to discontinue these herbal supplements prior to allergy skin testing.
Subject(s)
Histamine , Plant Preparations/pharmacology , Skin Tests , Skin/drug effects , Terfenadine/analogs & derivatives , Cross-Over Studies , Double-Blind Method , Gastrointestinal Diseases/chemically induced , Histamine H1 Antagonists/pharmacology , Humans , Plant Preparations/adverse effects , Terfenadine/pharmacology , Time FactorsSubject(s)
Immunotherapy/adverse effects , Vocal Cord Paralysis/etiology , Acute Disease , Female , Forced Expiratory Volume/physiology , Humans , Middle Aged , Rhinitis, Allergic, Perennial/complications , Rhinitis, Allergic, Perennial/physiopathology , Rhinitis, Allergic, Perennial/therapy , Treatment Failure , Vital Capacity/physiology , Vocal Cord Paralysis/physiopathologyABSTRACT
In contrast to acute urticaria, etiology cannot be identified in most cases of chronic urticaria. Recent evidence suggests that a subset of patients with chronic urticaria may have an autoimmune basis for their condition. The demonstration of antithyroid autoantibodies in some patients with chronic idiopathic urticaria (CIU) provides support for an association. However, the discovery of a positive skin test response to intradermal injection of autologous serum in as many as 60% of patients with CIU led to the identification of autoantibodies to IgE and the alpha-chain of the high-affinity IgE receptor, Fc epsilon RI alpha. Additional studies have demonstrated that some of these autoantibodies are capable of releasing histamine from donor basophils and mast cells. This article reviews the literature that addresses a possible autoimmune etiology in a subset of patients with CIU. Urticarial vasculitis is differentiated from chronic urticaria based on clinical features and biopsy findings of leukocytoclastic vasculitis. Most cases of urticarial vasculitis are secondary to an underlying systemic disease. The presence of autoantibodies has also been demonstrated in a subset of patients with primary urticarial vasculitis. This article briefly reviews some of this data.
