Fingernail Changes in Relation to Psoriatic Arthritis

Fingernail changes beyond the current diagnostic criteria should be considered when observing the signs and symptoms of psoriatic arthritis, according to a study from McMaster University.

in the Journal of Cutaneous Medicine and Surgery. The current criteria include pitting, onycholysis, and hyperkeratosis as the 3 main changes to consider, though other changes should be taken into account, the authors believe.

Researchers from McMaster University in Ontario, Canada observed 188 PsA patients who underwent rheumatological assessments in order to explore the relationships between nail changes, psoriasis, and joint involvement in this patient population. Each participant had their hands and fingernails photographed and reviewed by a dermatologist to identify 9 different changes. By identifying the changes, the researchers hoped they could narrow down either more global or digit specific joint involvement.

In a separate meta-analysis of 50 years’ worth of literature, the investigators found that, on average, 66 percent of PsA patients experienced fingernail changes. The types of changes varied between the studies, though the researchers asserted that more studies on nail changes in PsA patients should be conducted.

The mean PsA duration from the patients (of whom 52.7 percent were male, 47.3 percent female) was 12.5 years. Nearly all of the patients (91 percent) experienced at least 1 nail change: 78.7 percent had at least 1 nail matrix change, while 73.9 percent had at least 1 nail bed change. More male participants had at least 1 change than the female participants (97.0 percent vs. 85.4 percent, respectively). The most common changes were pitting (59.0 percent), leukonychia (42.0 percent), rough onychorrhexis (23.9 percent). The most frequently observed nail changes in the 45 patients with rough onychorrhexis were onycholysis, pitting, splinter hemorrhages, and oil spots (66.7 percent, 62.2 percent, 53.3 percent, and 44.4 percent, respectively).

“The most surprising findings were surrounding what we termed rough onychorrhexis,” study author Matthew Sandre, a final year medical student at the university, explained to HCPLive in an email. “As defined in our study, rough onychorrhexis represented both nail beading and longitudinal ridging. We were unable to find PsA studies which considered either of the two components of rough onychorrhexis in their main analyses. Similar descriptions have been found in relation to other clinical situations such as rheumatoid arthritis and increased rates of nail growth, but none in relation to PsA. It is therefore possible that rough onychorrhexis may be a neglected clinical feature of PsA.”

The most frequently observed nail bed changes were splinter hemorrhages (55.9 percent), onycholysis (51.6 percent), and oil spots (27.7 percent). The most common changes were pitting, splinter hemorrhages, and onycholysis.

“If further studies show similar results, our results could help guide physicians to know which particular joints need further clinical examination,” Sandre continued. “For example, if a particular fingernail shows nail crumbling, then the distal interphalangeal joint on that finger should be closely examined for joint swelling/involvement.”