Treating Nail Psoriasis: Not Just a Cosmetic Issue

Crumbling, pitted nails are a common experience for patients with skin psoriasis. A 2007 study in the Journal of the American Academy of Dermatology found that as many as 90 percent of psoriasis patients will experience nail psoriasis at some point. Similarly, between 50 percent and 87 percent of patients with psoriatic arthritis have nail psoriasis as well.

The same 2007 study found that nail psoriasis has major impacts on quality of life, with 90 percent of patients with the condition reporting that they felt distressed by the appearance of their nails. Ninety percent also reported restricting their daily activities because of their nail condition. Understanding the presentation and treatment of nail psoriasis is thus key for rheumatologists, dermatologists and general practitioners who might encounter patients with nail psoriasis. A new article in the journal Clinical and Experimental Rheumatology aims to clarify the latest research.

Clinical features of nail psoriasis

Nail psoriasis can affect any portion of the nail, including the nail bed, nail matrix, nail fold and hyponychium, wrote researchers Racheal Manhart and Phoebe Rich, M.D., of the Oregon Dermatology Research Center. The changes patients present with in the clinic, however, usually stem from problems with the nail bed and matrix. These include white spots called leukonychia, red macula in the lunula, and pitting and crumbling of the nail plate. When psoriasis affects the nail bed, it can cause yellowish-orange spots called salmon patch dyschromia, also known as the "oil drop" sign. Nail psoriasis can also cause the nail plate to pull away from the nail bed.

Assessing nail psoriasis[[{"type":"media","view_mode":"media_crop","fid":"43709","attributes":{"alt":"©Deviant/Shutterstock.com","class":"media-image media-image-right","id":"media_crop_4236988187767","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"4811","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":" ","typeof":"foaf:Image"}}]]

There are multiple scales used to assess nail psoriasis, but the one used in most clinical trials is NAPSI, the Nail Psoriasis Severity Index. This scale uses a quadrant system to record the location and extent of psoriasis of the nail.

Treatment of Nail Psoriasis

• Education:  The first line of treatment for nail psoriasis is education, Manhart and Rich wrote. Patients should avoid repetitive actions that stress the nail and keep fingernails clipped short so that activities like typing do not put pressure on the nail. Physicians should also urge patients to wear gloves while doing chores or gardening. Nail polish is safe, but acrylic nails should be avoided. Patients also need to be aware that treatment of nail psoriasis takes time. For fingernails, it may take six months or more for damaged areas to grow out. For toenails, it could take up to a year.
• Low-level pharmaceutical treatment:  Treating nail psoriasis is similar to treating skin psoriasis, the authors wrote. Mild cases can be treated with corticosteroids, calcipotriol, tazarotene, tacrolimus creams or the new botanical Indigo Naturalis. Steroid injections into the lesions and phototherapy may be helpful if only a few nails are affected.
• Next-step pharmaceuticals:  If local treatment fails, systemic medications are the next step. But there are differences between effective systemic treatments for skin and nail psoriasis, Manhart and Rich warned. Medications such as cyclosporine A and methotrexate appear to have a limited effect on nail psoriasis. Biologics, on the other hand, have shown much more potential. Studies find that ustekinumab is an effective treatment, and phase 2 and 3 trials of ixekizumab and secukinumab are promising as well.

References:

1. Manhart, R. & Rich, P. Nail Psoriasis. Clin Exp Rheumatol 2015; 33(Suppl. 93): S7-S13.

2. Jiaravuthisan MM, Sasseville D, Vender RB, Urphy F, Muhn CY: Psoriasis of the nail: anatomy, pathology, clinical presentation,and a review of the literature on therapy. J Am Acad Dermatol 2007; 57: 1-27.