How long have you had the lines? If it is mites and you have had them for six months or so, you would feel them running across your skin by now and also feel sharp needle pricks.
Is there any other symptom that makes you feel you may have skin parasites.?
How long ago did you take the Ivermectin, what dose ?
8 days is not really long enough. Is this the time you felt tickly sensations on your back, when you too the Iver?