Mast Cell Stabilizers for Post-tick Bite Illness

This trial explores new ways to treat ongoing symptoms after a tick-borne illness, such as Ehrlichiosis or Rocky Mountain Spotted Fever, using a combination of medications that stabilize mast cells, which are involved in allergic reactions. Participants will receive either standard care with fexofenadine or a combination therapy that adds ketotifen and cromolyn sodium, both mast cell stabilizers, to fexofenadine. The trial targets individuals who have had a tick-borne illness in the past three years and continue to experience significant symptoms affecting their daily life. As a Phase 2 trial, the research focuses on measuring the treatment's effectiveness in an initial, smaller group of people.

The trial does not specify if you need to stop all current medications, but you must avoid using diphenhydramine (Benadryl) during the study. Additionally, you cannot have used omalizumab within 6 months, systemic steroids within 28 days, or zileuton within 14 days before starting the study.

Research has shown that cromolyn sodium is FDA-approved for treating asthma and mastocytosis, a condition with an excess of mast cells in the body, indicating its general safety. Some studies report that cromolyn can start improving symptoms within 2-6 weeks, with effects lasting several weeks after discontinuation. Side effects are usually mild and may include headaches, nausea, or diarrhea.

For ketotifen, ongoing research explores its use in tick-borne illnesses, though it is also used for asthma and allergies. While specific safety information in humans is limited, it is generally considered safe for these conditions. Ketotifen can cause mild side effects such as drowsiness or dry mouth.

Researchers are excited about using mast cell stabilizers like cromolyn sodium and ketotifen for post-tick bite illness because they target the immune system differently than standard treatments. Most current therapies focus on symptom relief or antibiotic treatment, but these drugs work by stabilizing mast cells, which play a role in inflammation and allergic reactions. By preventing mast cells from releasing inflammatory substances, these treatments could potentially address the root cause of symptoms more effectively. This novel approach offers hope for better outcomes, especially for those who do not respond well to existing therapies.

Research has shown that cromolyn sodium and ketotifen can help manage symptoms of mast cell activation disorders, which may occur after tick bites. Cromolyn effectively relieves stomach-related symptoms, while ketotifen addresses allergy-like symptoms. In this trial, participants in the Mast Cell-Directed Combination Therapy arm will receive both ketotifen and cromolyn, along with fexofenadine, to evaluate their combined effectiveness. Previous users of these medications have reported manageable side effects. These treatments stabilize mast cells, which play a role in allergic reactions and inflammation. As a result, they might reduce symptoms of illnesses that occur after tick bites, such as Alpha-gal syndrome.¹⁶⁷⁸⁹