Martin is allergic to horses. He didn’t always present as allergic to horses. When he was four and five years old, he did hippotherapy weekly, without problems. When he was eight years old, on a visit to Costa Rica, we went horseback riding on the beach: Martin, Adrian, my brother-in-law Pancho, and I. We rode for an hour. I was second in line; Martin, wearing shorts and a small t-shirt, was third. Every few minutes I turned around to glance at him, make sure he was still riding comfortably. I saw no issues. But when we arrived back at the stables, and I was able to see Martin up close, I could see that he was covered in a red rash. Rashed on his arms. Rashed on his legs and, I soon discovered, on his chest and belly. Most of all, rashed on his face, which was red and bumpy. “What’s wrong with me?” he exclaimed and burst out crying. I checked his breathing (it was okay), took him back to our rental house, and put him in the shower. With good scrubbing and an antihistamine, the rash dissipated.

After the Costa Rica experience, I asked Martin’s allergist—a mainstream doctor, not focused on ASD—to test Martin for a reaction to horses. The doctor agreed, though he had to order a special skin test. When it was finally available and administered, the test left no doubt: Martin’s forearm immediately swelled into a red bump. No more horses.

On that same Costa Rica trip (August 2016), we discovered Martin had become allergic to red meat.Sixteen months earlier, in February 2015, in South America, Martin was eating beef with roast potatoes when a red rash formed around his mouth.(That trip, however, he’d ridden horses with his cousins, no problem.) Still I didn’t realize that red meat, which he rarely ate, was the issue; of the Costa Rica trip, I wrote: “He had two allergic reactions, one to a horse that left his face bumpy and itchy, and one to an unidentified food irritant (restaurant) that caused a rash to spread from the corners of his mouth down his neck.” Subsequently I put the pieces together and stopped letting Martin eat beef—but it would be more time yet before I figured out that all red meats were problematic, not just beef. (That discovery, in a “bison incident,” is described here.)

This summer, in Costa Rica again, Martin’s day camp was having an activity in which the kids rode horses to a remote waterfall. I wondered: The allergy came on when Martin was already six (or seven? or eight?) years old. Does he still have it? These Johnny-come-lately allergies—do they stick around? I wanted Martin to be able to participate in the horseback-riding activity, and not to experience one more factor differentiating him from other kids.

So I acted recklessly. (Maybe?) I told the camp director that Martin is allergic to horses. I told her about Martin’s reaction two years earlier, also in Costa Rica. I said I was going to dress Martin in long sleeves, long pants, and high socks, and send him to camp. I asked her to let Martin give the activity a try and see what happened. I reminded her that Martin always carries antihistamine in his backpack, just in case.

Mid-morning, I received a message from the camp director. Martin had only been on the horse a few minutes when he got a terrible rash. She took him off the horse immediately and administered his antihistamine. The reaction was severe enough that she also took him directly to a shower to wash. Thankfully, he was better within a short time.

That’s that. Martin has become allergic to horses, possibly permanently, just as he has become allergic to cats and dogs and has become allergic to red meat.

I am, of course, back to pondering why Martin has developed allergies as he continues to heal. I still think the most likely explanation is that he had these allergies (with the possible exception of red meat, which may or may not be related to Lyme disease) all along, but previously his immune system was neither strong nor responsive enough to mount the proper response. Whereas allergies themselves represent flaws in immune function, perhaps one day Martin’s full recovery will mean the allergies dissipate along with the remaining vestiges of autism.

Today, let’s not dwell on the allergies, and what they might mean. Instead, let’s focus on this: According to the camp director in Costa Rica, Martin didn’t freak out, not even when he was covered in a rash and pulled away from the other kids. She said he was upset for a minute or two, then calmed down. Two weeks later, when the activity again was horseback riding, I offered Martin a choice: He could go to camp and play games or surf while the other kids rode (the director had offered this alternative), or he could take the day off and go to the beach with Uncle Eddie. Martin contemplated for a while, then chose to take the day off. It seemed like a reasonable choice, and it wasn’t a big deal.

Because now, not everything has to be a big deal.