First off, if anyone can actually diagnosis and/or give me any idea of what this it will be GREATLY appreciated, so, here is my story:
Around March of this year my girlfriend noticed I had these weird spots on my lower back. There were around four or five of them. The largest was nearly the size of a penny. I don't have any pictures of these spots, but I will try to provide a description. At first glance, my dad simply asked me if someone had been putting their cigarettes out on my back. They were almost perfectly circular, and had a scab in the middle. Not really raised from my skin, but more of an inset type scab. I went to see my first doctor then, he had no explination but his best guess was spider bites. He didn't prescribe me anything, but said to clean my room and to use some insect killer. So, I did. After I had this cluster on my lower back there started to be the exact same thing on my right shoulder, going down to around my bicep. Same thing, but smaller bumps. It was around this time that the originals on my back had started to change. The scabs fell off, and scar tissue began to form. This cycle continued, but the spots kept getting smaller, and less clumped. Today, I have the five on my back, four or so on my shoulder and arm, two on my forearm (one that is new as of July 4th), two on my chest, and now, as of three days ago, two on my right leg. Between all this time I have seen a dermatologist, and two different doctors. I have had blood tests, urinanalysis, a culture, and a biopsy. All of which have came up with negative results. This problem alone has some frustrating details, I have often gone down to a friend's lake house, roughly an hour away. The house does have bugs in it, and for the most part these spots have appeared after I visit the lake house (besides two of the times I got these spots). These things do not itch, they do not puss, and if I hadn't seen them I would have never known they were even there. Furthermore, no one else that stays at this lake house has gotten the same thing, and neither has my girlfriend who has slept in my bed multiple times. I'm eighteen years old, and am very healthy. I know many won't take the time to read this, and most will wonder why I'm asking people on the internet when professionals do not even have an idea of what it is that I have. I will try to edit this later and post some pictures. If anyone has even the slightest of ideas of what this is then please contact me via my email at firstname.lastname@example.org. Thanks.