Psoriasis is a persistent, inflammatory condition that most commonly affects the skin but may also involve the nails. Psoriatic nails often have tiny pits and may become loose, thick or crumbly, all signs that may be misdiagnosed as a nail infection. Psoriasis is not contagious and cannot be passed from one person to another. It does tend to run in families, so it may be an inherited condition.
There is no cure for psoriasis and it is challenging to treat in the nail. The nail bed is difficult to penetrate with topical medications. Corticosteroid injections into the nail bed have been used with some success as have some types of light therapy. Cosmetic repair including nail scraping and filing may help improve the appearance of psoriatic nails.
Because damage to the nail can often trigger the onset of psoriasis or worsen the condition, it's important to protect your nails by wearing gloves while working with your hands.