Psoriatic arthritis is a chronic autoimmune-based inflammatory disease that occurs in about 30% of people with psoriasis.
Like other forms of arthritis, the disease predominantly affects the joints of the hands and feet (in particular, those between the distal phalanges) and, in severe cases, can have deforming outcomes.
Joint involvement is, as a rule, asymmetrical (i.e., different between the right and left sides of the body) and can also affect the spine at different levels.
The development of psoriatic arthritis is not correlated with the severity of psoriasis, to the point that in some patients the dermatologic disease is recognized only after characterizing joint damage and excluding the presence of other forms of arthritis (in particular, rheumatoid arthritis).
In these cases, usually, the skin plaques typical of psoriasis are very small, inconspicuous, and/or located in “hidden” areas such as the scalp, body folds, or genital area.
