Psoriasis is a common, chronic, and recurrent inflammatory disease of the skin. It is characterized by round, reddish, dry scaling patches covered by grayish white or silvery white scales. The lesions have a predilection for the nails, scalp, elbows, shins and feet. On the feet, it can be difficult to distinguish it from athlete's foot, and the nail appearance may be confused with fungal infections of the toenails. The nail appearance does have a unique characteristic; it may have a pitting appearance. A characteristic feature of the condition is pinpoint bleeding when the scaled areas are brushed off. A variant of psoriasis is called pustular psoriasis. This form of the disease is characterized by small pustules or blisters filled with clear or cloudy fluid. This can mimic acute athlete's foot. It characteristically does not itch or burn. It is distinguished from athlete's foot by negative fungal cultures. The picture can become confusing because a secondary fungal infection is possible. In this instance both conditions are present at the same time.
Psoriasis can also affect the joints of the feet and lower extremities causing a painful arthritis. X-rays will show characteristic erosions of the bones in the toes. Treatment consists of anti-inflammatory medications, steroids, and other medications specific for the treatment of psoriasis.