Table 4 Studies comprising quantitative results on PD^a

Aydin et al. (2017) [27]

PsO

NPD: 84.6%

Presence of nail bed with PD signal was similar among patients with PsO and healthy controls.

Controls

NPD: 81.6%

Paramalingam et al. (2017) [29]

PsA

NPD: 96.0%

Patients with PsA presented with a slightly higher percentage of nails with PD signal than patients with OA.

OA

NPD: 95.0%

Acquitter et al. (2016) [30]

Patients with PsO with nail disease

NPD: 44.5%

NPD was higher in patients with PsO with nail disease; however, differences among groups were not significant.

Patients with scalp PsO and/or inverse PsO

NPD: 39.0%

Mendonça et al. (2014) [34]

PsA

NPD mean (SD): 0.88 (0.31)

NPD was slightly lower in patients with PsA than controls.

Controls

NPD mean (SD): 1.0 (0.00)

Sandobal et al. (2014) [35]

PsO

Increase PD signal in nail beds: 20.5%

Patients with psoriatic arthropathy showed increased PD signal in nail bed (p = 0.0001).

PsA

Increase PD signal in nail beds: 23.4%

RA

Increase PD signal in nail beds: 2.2%

Controls

Increase PD signal in nail beds: 19.6%

Haddad et al. (2012) [39]

PsO

Nail bed vascularity: 14%

Comparing the three groups, patients with PsO and PsA presented with statistically significantly lower values of nail bed vascularity than controls (p < 0.001).

Comparing patients with PsO and PsA, patients with PsO presented with lower nail bed vascularity than patients with PsA; however, no statistically significant differences were observed (p = 0.44).

PsA

Nail bed vascularity: 18%

Controls

Nail bed vascularity: 20%