Ok so context, before I hit puberty my blood must have been delicious because I was getting bitten by anything with bitey parts, this may be relevant, I'm not sure.

Anyway one day I notice a dark mark on my arm, I study it for a moment and realise it's growing, not outwards across the skin like a rash, but upwards out of my body. It looked like a column of mostly dry soil, it eventually grew to almost 2cm before it just sort of stopped and fell off, didn't leave a trace behind.

This incident has been stuck in my head for 20 years and I can't make sense of it. My assumption, looking back, is that some sort of parasite had made its home in my skin (mi epidermis es tu epidermis) and I may have witnessed a simple defecation.

It may have emerged from (what I assumed to be) a bug bite but that detail eludes my memory at the moment.