The study aimed to evaluate the effect of retinoid treatment on the morphological changes in the nail apparatus in patients with nail psoriasis.
Material and methods: 41 patients aged 32 to 64 with nail psoriasis, without clinical signs of psoriatic arthritis, started on acitretin 0.6 to 0.8 mg kg b.w./d, for six months and 28 people in the control group were included in the study. Both groups had ultrasound examination of fingernails and digital extensor tendon in the distal interphalangeal joints. In psoriatic patients, US examination was conducted before starting the treatment and after six months. A total of 685 nails were examined.
Results: After six months of treatment, there was a reduction in the thickness of the nail bed and nail matrix (p = 0.046 and p = 0.031, respectively). The thickness of the nail plates decreased, although it was statistically insignificant (p = 0.059) and it was higher than in the control group (p = 0.034). The reduced severity of clinical nail changes after six months of retinoid treatment did not correlate with the reduction in extensor tendon thickness in any group of patients.
Conclusions: In patients with nail psoriasis, acitretin treatment resulted in a rapid decrease in the thickness of the nail bed and matrix, but it did not affect the thickness of the nail plate after six months. There was no effect of acitretin on the digital extensor tendon thickness or the increased blood supply to the tendon area. The results of the study may indicate the usefulness of ultrasound nail examinations in patients with nail psoriasis not only to assess the advancement of morphological changes and response to treatment, but also to choose the potential treatment.
Keywords: acitretin; enthesopathy; nail psoriasis; nail ultrasound.