Table 2:
Examples where the presence of IgE and antigen elicits no reaction Examples where the presence of IgE and antigen elicits no reaction Examples where the presence of IgE and antigen elicits no reaction Examples where the presence of IgE and antigen elicits no reaction
Fact Explanation Explanation
Drug tolerance during initial IgE sensitization
During an e.g. 10d therapy with amoxicillin, no symptoms appear, although specific IgE is already formed and MC are sensitized During an e.g. 10d therapy with amoxicillin, no symptoms appear, although specific IgE is already formed and MC are sensitized
Bee keepers tolerate bee stings when they carry IgE to bee venom. Bee keepers with IgE (and often IgG) to bee venom react with urticaria and (often mild) anaphylaxis in springs after the first bee stings, which subsides as the season carries on. Bee keepers with IgE (and often IgG) to bee venom react with urticaria and (often mild) anaphylaxis in springs after the first bee stings, which subsides as the season carries on.
Bee or wasp allergic individuals tolerate 50µg venom already after 3,5hrs of immunotherapy (23). Protocol: S.c injection of increasing concentrations of venom (0.1 µg - 1 µg - 10 µg - 20 µg - 30 µg - 50 µg (>111mg)) within about 3.5 h. Transient MC-unresponsiveness is achieved in IgE-sensitized individuals after 3.5 h with a tolerance of 50µg venom; Further injections (100µg) are well tolerated at day 7, 21 (22, 23). Protocol: S.c injection of increasing concentrations of venom (0.1 µg - 1 µg - 10 µg - 20 µg - 30 µg - 50 µg (>111mg)) within about 3.5 h. Transient MC-unresponsiveness is achieved in IgE-sensitized individuals after 3.5 h with a tolerance of 50µg venom; Further injections (100µg) are well tolerated at day 7, 21 (22, 23).
Drug desensitizations can be achieved within a few hrs. Multiple schemes of desensitizations of IgE-mediated reactions to drugs exist (20, 21). Desensitization is achieved by starting with very low drug concentrations and increasing stepwise (30min intervals) until the normal daily drug dose is achieved in 4-6hrs. This desensitization is tolerated without symptoms. It is repeated after ca. 4 weeks before the next drug therapy. Multiple schemes of desensitizations of IgE-mediated reactions to drugs exist (20, 21). Desensitization is achieved by starting with very low drug concentrations and increasing stepwise (30min intervals) until the normal daily drug dose is achieved in 4-6hrs. This desensitization is tolerated without symptoms. It is repeated after ca. 4 weeks before the next drug therapy.
Sensitization without symptoms in spite of allergen exposure is frequent. Many sensitized individuals (IgE, skin test reactivity) do not show allergy symptoms. E.g. in the pollen season, the sensitized but not allergic individuals tolerate the pollen exposure without symptoms (ca 20µg inhaled major allergen/season). The skin tests are positive, as the local allergen concentration in skin testing is high (also ca. 10-20µg/ml major allergen) (26,27). Many sensitized individuals (IgE, skin test reactivity) do not show allergy symptoms. E.g. in the pollen season, the sensitized but not allergic individuals tolerate the pollen exposure without symptoms (ca 20µg inhaled major allergen/season). The skin tests are positive, as the local allergen concentration in skin testing is high (also ca. 10-20µg/ml major allergen) (26,27).