Nailfold capillaroscopy in psoriasis

Psoriasis a chronic inflammatory skin disease manifests with microcirculatory changes within skin which may precede skin manifestations, correlate with their severity, joint involvement and resolve with treatment. Nailfold capillaroscopy (NFC) is used in rheumatology for connective tissue disorder assessment and is assuming significance in psoriasis. The aim was to study the nailfold capillaroscopic findings in patients with psoriasis.

A cross-sectional observational study was carried out at a skin center of a tertiary care hospital from January 2016 to June 2017. Selected cases underwent NFC using a portable color capillaroscope with an attached computer with software to analyze the nailfold capillaries for morphological parameters and abnormalities. Independent-samples t test and chi-square test was used to analyze the relationships between variables.

Mean capillary loop density in 96% of study population was subnormal (<9 capillaries/mm), mean arterial limb diameter 11.37 ± 2.434μ; mean venous limb diameter 15.89 ± 3.131μ, top of the loop diameter 14.41 ± 4.373μ and length of the loop was 152.51 ± 57.21μ. Only 3 had length of loop >300μ. Bizarre morphology was seen in 15.5% of capillaries (p value < 0.001). Crossed loops/tortuous capillaries were seen in 17.3% of patients (p value < 0.001). Ramified capillaries were seen in 9.1% of patients with psoriasis (p value < 0.001). Other abnormalities observed were hemorrhage, avascular areas and subpapillary plexus. Widespread disease and psoriatic arthritis (18.2%) had irregular and haphazard distribution of capillaries (p value < 0.001). Analysis of Psoriasis Area Severity Index score, age of the patient and NFC did not reveal any statistically significant relationship.

Nailfold capillaroscopy (NFC), a non invasive imaging technique for microcirculation evaluation can serve to prognosticate and follow up patirents with psoriasis as a simple and highly reproducible tool. Nailfold capillaroscopy is a simple and an easy method to study the microvascular abnormalities in psoriasis. Findings correlate with disease severity. It can be used for follow-up as a predictor of disease worsening or response to treatment.