DS has this thing where his scalp actually hurts when he’s hot. Like tiny pin pricks that start as itchiness but end up painful and he wants to rip his scalp off. He says it’s bad when gets hot but then once covered in sweat (if he’s exercising) it relieves itself. He has what looks like sebhorric dermatitis so presuming it’s that. We’ve tried various shampoos. Booked a doctor’s appointment but as a lifelong eczema sufferer myself am not feeling optimistic. He is 16. Anyone have similar/ any advice?