Palmoplantar and guitar?

Hi there. My question is for anyone who suffers from palmo-plantar psoriasis and plays the guitar. My son was diagnosed with palmo-plantar psoriasis last year after he had burned the palm of his hand on a hot kettle and got a blister that simply would not heal. I have since learned that an "injury" can trigger an outbreak and certainly he has pretty classic palmo-plantar symptoms on hands and feet (the feet had come first but we didn't know what it was). He is pretty good about looking after outbreaks (he's 12) but I am always on guard for things that might cause "injury". He has shown an interest in playing guitar but I know that the fingers get a real callus on them after extended playing. My question is: does playing guitar trigger outbreaks to the hands? Just wondering if anyone has experience with this. Thanks.