Clinical and serological characteristics of nail psoriasis in Indian patients: A cross-sectional study

Background: Nail involvement in psoriasis is common with a lifetime incidence of 80-90%. It may reflect severity of cutaneous involvement and predict joint disease. Yet it remains, poorly studied and evaluated especially in Indian psoriatic patients. Aim: The present study was undertaken to evaluate clinical and serological profile of nail involvement in psoriasis and to assess quality of life impairment associated with nail involvement in Indian patients. Methods: Consecutive patients with nail psoriasis were assessed for severity of cutaneous disease (psoriasis area severity index score) and nail disease (nail psoriasis severity index score). The impairment in quality of life attributable to nail disease was scored with nail psoriasis quality of life 10 score. All patients were also assessed for joint disease and tested for inflammatory and serological markers as erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor and anti-cyclic citrullinated peptide antibodies. Results: In our cohort of 38 patients with nail psoriasis, 9 had concomitant psoriatic arthritis. The mean psoriasis area severity index was 14.4 +/- 9.6 (range = 0.4-34). The most commonly recorded psoriatic nail changes were pitting (97.4%), onycholysis (94.7%) and subungual hyperkeratosis (89.5%). The mean nail psoriasis severity index score was 83.2 +/- 40.1 ( range = 5-156) and mean nail psoriasis quality of life 10 was 1.1 +/- 0.4. Erythrocyte sedimentation rate and C-reactive protein were raised in 22/38 (57.9%) and 15/38 (39.5%) patients, respectively; rheumatoid factor was positive in 5/38 (13.2%) and anti-cyclic citrullinated peptide antibody was raised in 4/38 (10.5%) patients. Limitations: Small sample size and lack of a control group. Conclusions: In Indian patients with nail psoriasis, severity of nail involvement was found to be poorly correlated with the extent of cutaneous disease. In addition the impact of nail disease on patient's quality of life was found to be minimal. This suggests the need for a quality of life questionnaire suited to the Indian population. Serological markers were raised overall in the study patients and more so in the patients with concomitant arthritis.