Hi, It seems that your son may be having prurigo simplex.. It is a chronic relapsing disease caused by many factors..like stress,anxiety,irritants,allergens,cosmetics,fume,deoderant,dust,housedust mite , soap,detergents,insects,clothes,wool,drugs..etc. He may be atopic . Cows milk,sea food, fermented food,banana,colored drinks..etc may exacerbate the disease. Antihistaminics, like levocetirizine may be given to relieve itching. Steroids in tapperin dose for short period may be given. Apply steroid cream. Tell him to avoid soap bath. I think he may be improved. Still, you consult dermatologist. I hope you got my answer. Thanks. Dr. Ilyas Patel MD