A week later, Kahwash received an email from the woman through his patient portal. She was still miserable — still covered with hives, still not sleeping at all. What was the next step? He immediately ordered an intravenous medication known as omalizumab.
Just Give Me the Steroids!
This monthly medication — often used to treat severe asthma — is a lab-made antibody that attaches itself to the mast cell to prevent the release of histamine. In one study, the drug eliminated both itching and hives in about half of patients who took it, and nearly everyone felt better after three months on it.
After six weeks on the omalizumab, the woman got back in touch. Just give me the steroids, she pleaded. That was the only thing that helped. To Kahwash, daily low-dose steroids were a last resort. Prednisone had too many side effects to use long-term until all other avenues had been exhausted. And he had one more option: a powerful but targeted immune-system suppressor called cyclosporine. It is most commonly used in organ transplantation. This was a big gun, but it was still preferable to prednisone. Kahwash started her on a low dose of cyclosporine.
Her next appointment with him was three weeks later. When she arrived, Kahwash was shocked to see that her hives were just as bad as they were when he first saw her. Had the diagnosis been wrong? People often think that hives are a response to an outside trigger — an allergic reaction — but that’s almost never the case with urticaria that lasts for weeks. C.I.U. is usually caused by overreactive mast cells. What makes them overreact is still not well understood. Still, treatment is usually straightforward. But Kahwash hadn’t made a dent in this patient’s hives despite high doses of two antihistamines, two mast-cell stabilizers and cyclosporine.
So what else could this be? There are a handful of autoimmune diseases that can cause chronic hives. A form of autoimmune thyroid disease can do it. Lupus too. It’s a rare symptom in both, but possible. Another disease, mastocytosis, involves the body simply creating too many mast cells, with that proliferation causing all sorts of misery, including chronic hives. Finally, a handful of food allergies might do this. These mostly occur in children, and usually the reaction comes right after the food is eaten, so the link between food and reaction is rarely a mystery.
But there is an exception, an allergy described just over a decade ago — an allergy to meat. Many people who have this allergy report that their worst symptoms happen in the middle of the night, hours after a meat-filled dinner. All these possibilities were rare, but so were her tough-to-treat hives. Kahwash sent the patient to the lab to get tested for each of them and started her on a higher dose of cyclosporine.
A Small Price to Pay
The test results came back the following week. Her thyroid was fine. It wasn’t lupus. It wasn’t mastocytosis. The test for the meat allergy took longer. But it finally provided the answer: The patient had developed an allergy to meat.
Kahwash had seen this allergy in a handful of his patients and knew it was a strange one. Most allergies are triggered by proteins, but this was a reaction to galactose-α-1,3-galactose (known as alpha-gal for short), a sugar. And the reaction to the allergen took hours, not minutes, to appear. Strangest of all, this allergy is triggered by a tick bite. In the United States, the lone star tick, found predominantly in the Southeast, has been identified as the vector. In other countries — it has been reported on every continent except Antarctica — other ticks are involved.