Dear Dr. K: My friend and I, who have both been on allergy shots for four years, went off them. My friend remains allergy-free, but my allergies are coming back again. What gives? That is a simple question to ask, but a more difficult one to answer. Let’s start with how allergy shots work. Actually, we should call them allergy vaccines because all vaccines lead to the production of protective antibodies (called IgG). For example: in the case of tetanus vaccine, it leads to antitetanus antibodies. Similarly, an allergy vaccine against ragweed leads to protective IgG antibodies against ragweed. These IgG antibodies interfere with the allergic antibody (IgE) from interacting with ragweed and hence, prevent the allergy symptoms. The longer a person receives an allergy vaccine, the greater the level of protective antibodies. Everyone who receives allergy shots experiences this response. A second benefit of allergy shots is to gradually turn off IgE production. Unfortunately, this doesn’t happen in everyone. It’s the diminution of IgE that leads to long-term remission from the allergies. Your friend undoubtedly has had this benefit.  A few other issues are worth mentioning. People living in southern climes tend to need allergy shots longer than their northern neighbors. The absence of winter freezes leads to higher levels of both indoor and outdoor allergens year-round. Outdoors is obviously more challenging as there is a year-round growing season. Indoors, both mold and dust mites persist through the winter. This is because of persistent indoor humidity. Up north, the months of dry heating kills indoor mold and dust mites. Finally, there is the issue of animal allergy. People with dog and cat allergy tend to need these allergy shots for a longer period — especially for cat allergy.

which leads to sleep deprivation and symptoms of anxiety and depression. For many people with this measure of eczema, topical therapies just don’t work. The available systemic treatments are often associated with significant toxicity or side effects. Hence, there is a great need for a safe and effective long-term therapy. Dupilumab seems to fit this need. The two main side effects were injection site swelling (8 to 19%) and conjunctivitis (2 to 5%).