Check out Dermographism, I have same thing, google its a strange thing comes and goes I cant dry my skin properly because I break out ,itches for a few mins then disappears , I get high blood sugar ,not diabetic but higher than normal, so I am researching to find out why, anti histimines dont help much or cortaid creams I have tried everything ...
The same thing was happening to my boyfriend. It turned out to be nothing other than slight scratches. He changed sleeping locations, and they stopped showing up. There was very small pieces of wood or briers stuck in his mattress. They were so small and difficult to find. We could feel them when we put pressure on the bed. They were leaving light scratches that looked like a rash from when he would move in his sleep.
Hi,
How are you? Are there other symptoms associated with this line rashes? This could be an irritation, allergic reaction or even skin conditions such as eczema or dermatitis. Try to avoid scratching the lesion to prevent secondary infection. If it is an irritation, identification of the irritant and avoidance may help prevent their recurrence. If it persists, you may need to have this evaluated further to rule out the differentials mentioned. Antihistamine medicationsmay also help. Take care and best regards.