This infestation of scalp
with lice in our terms is known as pediculosis capitis
. The area of scalp adjoining nape of neck is the area of maximum involvement and that is why you had multiple pus filled lesions and rashes in that area. The enlarged lymph node
is basically due to lice only and once the infestation is treated it will regress in a few weeks time. Lice infestation
can be treated with permethrin 1% local application in dry hair for 10 minutes and then rinsing it with water only. The treatment should be repeated after 10 days for complete cure. Also a course of antibiotic can be taken to treat rashes and eleveted lesion over your scalp. Hope that solves your query.