Psoriasis is a condition that most frequently manifests itself on the skin. When the nails are involved, the function of the nail unit becomes impaired. The psoriatic nail may not be able to protect the finger or toe, perceive fine touch or sensation, pick up small objects or scratch. The most common misdiagnosis of psoriasis of the nail is fungal infection. In fact, the signs and symptoms of nail psoriasis and onchomycosis (nail fungus) can be indistinguishable. It is absolutely essential that your client's doctor perform the necessary tests in order to arrive at a correct diagnosis. (It is not a nail technician's responsibility to "diagnose" any nail condition.) The changes in the nail that occur when psoriasis is present include onycholysis (separation of the nail from the nail bed) and subungual hyperkeratosis (thickening of the nail bed). Other signs of psoriasis include splinter hemorrhages, reddish-brown discoloration of the nail bed, and white spots on the nail plate. It should be made clear that psoriasis of the nail is a serious and often disabling condition. It should be accurately diagnosed by a physician who will perform the necessary tests (including a KOH wet mount, culture, and possibly a nail biopsy) before starting treatment. After confirming that nail psoriasis is present, an appropriate and safe routine should be established, tailored to the type and severity of the disorder. Clients with nail psoriasis should not wear acrylics because the acrylic can sometimes aggravate the condition.