My Thumb, the Injections, and a Rusty Gear Shifter
For four weeks, something kept hurting my thumb. I had a theory. I was completely wrong.
Every spring in Berlin I get this mixed feeling — relieved the dark winter is finally over, but already dreading allergy season. I sneeze constantly, my eyes water, and it’s genuinely miserable.
A friend told me about desensitization shots. Basically a treatment where they expose you to small doses of the allergen over time until your immune system stops overreacting. I was into it, until I heard the full plan: five shots, one per week, every year, for three years. Still, I figured it was worth it.
The clinic is about 7 km from my place. I dug my bike out of storage and rode over — hillier than I remembered, which is saying something for Berlin. Got the first shot, waited thirty minutes in case of an anaphylactic reaction, and headed home. The doctor told me to watch out for any unusual symptoms.
Next day, my right thumb started hurting. Right under the nail. I figured I must’ve knocked it pulling the bike out of storage and forgot about it. Pain was gone in two days.
Week two, same thing. Shot, wait, ride home, sore thumb. This time I was pretty sure I hadn’t bumped it anywhere. I started doing the mental math — what are the odds my thumb hurts in the exact same spot, the exact same way, right after each shot? But I talked myself out of it. It had to be a coincidence. I wasn’t about to walk up to my doctor and say “hey, my thumb hurts after your injections.”
Third shot, I had a plan. I asked the doctor to give the injection in my left arm this time — just to see if my left thumb would hurt instead. I didn’t say why. On the way out I casually asked the nurse what kinds of symptoms people usually get after desensitization shots. Thumb pain wasn’t on the list. Next day: same right thumb, same spot, same ache. Alright, I was convinced. I had to say something.
Fourth visit, I told the doctor: “Every time I get the shot, my right thumb hurts. Is that a thing?” She gave me this look — somewhere between confused and trying not to laugh — and said no, she’d never heard of that. Ever. I left pretty sure she thought I was making it up.
Riding home, I hit an uphill stretch and went to shift gears. The shifter was stiff as hell, like it hadn’t been oiled in years — because it hadn’t. I squeezed harder than usual to get it to move.
Oh.
It wasn’t the shot. It was the bike.