Epidermolysis bullosa acquisita is a blistering disorder affecting the knees, elbows, hands, and feet. It generally occurs in persons who have had Crohn's disease for many years. The cause of these problems is unknown. Vitiligo resolves spontaneously in some cases. In other cases, treatment may include ultraviolet light therapy, oral medications, and medicines applied directly to the affected areas.
Psoriasis is treated in a similar manner, though with different medications.
There is no treatment available for clubbing.