Hi,
Welcome To HCM & Thanks For Asking Your Query Here
its good that he has no permanent damage to any major organ , but he has damaged his muscles and skin a lot which needs enough time to recover completely
to hasten his recovery
-Stop activity and do more rest
-drink plenty of electrolytes and fruit juices
-don't drink alcohol at all
-eat healthy diet including fresh vegetables , fruits , salad , and if feel better he may gradually increase the intake of protein diet including eggs , chicken , fish , mutton
apart from this finally i would strongly suggest you to see Your dr , he will prescribe some medications including anti inflammatory drugs like
ibuprofen ,
muscle relaxant like thiocholchicoside , also he may give him some multivitamins and minerals for fast recovery , and if his skin lesions are seems to be infected , your dr may opt for antibiotics
I hope it help
Thanks & Get well Soon