She did a skin prick test right there in her office. Twenty different allergens. Little pricks on my forearm, each one labelled.
"We'll wait fifteen minutes," she said.
When she came back, I watched her face change.
Three of the test sites had welts the size of twenty-cent coins. Red. Raised. Angry.
She pointed to the largest one.
"This is dust mite allergen. Der p 1. This is one of the strongest reactions I've seen."
I stared at her. "Dust mites? That's what's doing this to me?"
She pulled up a photo on her screen.
A microscopic creature. Eight legs. Pale, translucent, covered in tiny bristles. It looked like something from a horror film.
"This is a dust mite," she said. "They're a quarter of a millimetre long. Completely invisible. And right now, there are likely between one and two million of them living in your mattress."
My stomach dropped.
"They feed on dead skin cells — which you shed constantly. They burrow deep into the fibres of your mattress, your pillows, your carpet. You can't vacuum them out. You can't wash them out. They're too deep."
I felt sick.
"But here's what's actually making you ill. Each mite produces roughly twenty fecal pellets per day. Those pellets contain a protein called Der p 1. It's a potent allergen. The pellets are microscopic — they become airborne easily — and when you sleep, your face is just inches from the source."
She let that land.
"You've been inhaling millions of allergen particles every night for years. Your immune system has been in overdrive the entire time — fighting something you can't see, can't smell, and didn't know was there.
That's why you're exhausted. That's why you're congested. That's why every test comes back normal — because you don't have a disease, Margaret. You have an environmental trigger that's been attacking your body while you sleep."
I sat there in silence.
Three years.
Three years of doctors telling me nothing was wrong. Three years of wondering if I was weak.
If I was losing it. If this was just what getting old felt like.
And it was dust mites. In my own bed.