Muehrcke lines associated to active rheumatoid arthritis.

Careful examination of the fingernails and toenails can help to detect underlying systemic diseases. Physicians should look for shape, growth, or color changes in the nails; the transverse nail discolorations include different diagnostic possibilities such as Muehrcke lines and Mees lines. Leukonychia striata or Muehrcke lines are transverse nail bands of discoloration that are unspecific, and there are around 70 different causes that include cancer treatment and less commonly rheumatic diseases. In this case, we report the unusual presentation of Muehrcke lines associated with active rheumatoid arthritis.