During the car accident was there any associated head or scalp
Was there any open wound in the scalp
Shingles may occur in the scalp
. It may be managed with pain relievers as antivirals like acyclovir are only
effective once initiated early on. These medications also have some side
effects. Shingles may resolve spontaneously after 3 weeks and they usually present with crusts and tingling pain.
Another differential for your friend is folliculitis.