What is pachyonychia congenita? Pachyonychia congenita is a very rare disorder. It causes thick nails and painful calluses on the bottoms of the feet. In some cases, blisters also form on the palms of the hands.
What is rosacea? Rosacea (ro-ZAY-she-ah) is a long-term disease that causes reddened skin and pimples, usually on the face. It can also make skin thicker and cause eye problems.