Jonathan:
Actual pustules on the scalp generally are not seborrheic dermatitis. They are either
infectiousInfectious endocarditis
Infectious mononucleosis
Infectious mononucleosis #3 (staph) and require antibiotics, or else they are strss-related, perhaps from picking and squeezing. They aren't usually hereditary, in my experience. I'd see a dermatologist for culture and definitive diagnosis.
Best.
Dr. R