Skin problems are common with Crohn's Disease. I am having a lot of trouble with my hands (very dry, cracking) and some sores on my head. I'm lucky to have thick hair so the sores are not noticeable. The sores come and go for me, and I haven't noticed any hair loss. My brother who also has Crohn's has thinning hair. It is unusual as our father has a thick head of hair, he's in his 60's to boot. My mother's father and brothers had full heads of hair. There is no reason why my brother's hair should be thinning, so I do think it might be a side effect from his Crohn's.