Discussion
obesity, skin disease, comorbidity, Psoriasis, psoriasis, nail disease, Psoriatic Arthritis, skin lesions
OBESITY, SKIN DISEASE, DISEASE PROGRESSION, PSORIASIS, DISEASE, PSORIASIS, NAIL DISEASE, NAIL PSORIASIS, PSORIATIC ARTHRITIS, REGRESSION, SKIN LESIONS
These Following guselkumab withdrawal at week 28, nail response appeared to be maintained for longer (or increments of worsening were numerically smaller) compared with skin response. By contrast, following adalimumab withdrawal, nail response and skin response were lost over similar timeframes. Our data are descriptive only, and we cannot rule out the possibility that these apparent differences are artefactual. However, if they are not, a possible reason could be the variation in the mechanism of action of these biologics. In psoriasis, it has been shown that selective inhibition of IL-23 blocks downstream production of IL-17A and IL-22 by Th17 and other cells. The number of pathogenic cells may therefore be reduced, as many IL-17A producing cells are dependent on IL-23 for survival [Regardless of the biologic received, loss of nail response appeared more prominent in the nail bed than the nail matrix. This may be due to the anatomical differences that govern how long it takes for signs of disease to manifest at these sites. Nail bed flares may represent skin disease beneath the nail plate, whereas nail matrix manifestations of psoriasis start deep at the point of nail plate formation and, thus, the rate at which changes in the nail matrix can be observed is limited by the rate of nail plate growth [The multiple logistic regression analysis suggested that less severe nail disease (lower baseline NAPSI) and better skin response (lower week 16 PASI) were associated with a higher probability of near or complete nail psoriasis clearance (NAPSI 0/1) at week 24 and week 48, suggesting that in clinical practice, patients who achieve a high level of skin clearance by week 16 may have a higher likelihood of achieving clinically relevant nail outcomes over time versus those who do not. Data of this type are important because the slow growth of nails relative to the skin means that complete nail replacement is protracted, and nail improvement can take longer to manifest than improvements in skin lesions [Furthermore, it was suggested that baseline smoking status may have a weak association with nail psoriasis clearance (NAPSI 0/1 at week 48). Smoking is an independent risk factor for psoriasis [Our analysis showed no statistically significant association between BMI and the probability of achieving nail psoriasis response (NAPSI 0/1). This is important, as obesity is known to be a common comorbidity in patients with moderate-to-severe psoriasis, and studies have shown that body weight can affect skin response [These results suggest that nail outcomes should contribute to the evaluation of treatment efficacy and disease progression, which is consistent with recent guidelines from the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) [The current analyses had intrinsic limitations due to their 