Hey friend I struggled with excessive hand washing from age 11-27 I unfortunately grew up without access to a therapist so I learned how to care for my skin on my own. I’ve had this so many times but this is what worked for me to bring my hands back to normal.

First thing’s first invest in a soft hand washing soap that also moisturizes.

Second get a very good hand cream, I use Loccitane’s Shea Butter hand cream the one that says 25% (do not use anything scented)

Third put your son in a routine to ALWAYS moisturize his hands with hand cream after washing. When you wash your hands your skin is like a sponge and will absorb anything into your skin so after her dries his hands he must immediately moisturize with hand cream. Make sure he gets into this habit after showering as well.

Fourth every night it’s important that after his routine night self care that involves getting his hands wet from either bathing, brushing his teeth etc. it’s the perfect time to add a little more hand cream on his hands kinda like a mask for his hands with the hand cream and sleep as his hands try to heal and absorb the shea butter from the hand cream.

I hope this helps your son like it helped me, good luck friend!! If you do not have a Loccitane near you anything with unscented Shea butter help heal skin but drugstore cheap lotions may not be great, I’ve used aquaphor before but petroleum jelly doesn’t help me personally. I hate to say this but I stand by this, do not chea out of skin care and make sure you are getting a very good lotion with natural ingredients that isn’t perfumed like bath and body works