Table. Features of Study Cohorts.
| Cohort | United Kingdom | Northern Europe |
|---|---|---|
| Demographic characteristicsa | ||
| Women, No. (%) | 160/203 (79) | 161/193 (83) |
| Men, No. (%) | 43/203 (21) | 32/193 (17) |
| Age at onset, median (IQR), yb | 48 (38-59) | 45 (33-54) |
| Family history of psoriasis vulgaris, No. (%) | 65/203 (32) | 33/193 (17) |
| Family history of pustular psoriasis, No. (%) | 9/203 (4)c | 10/93 (11)d |
| Smoking status, No. (%) | ||
| Current | 90/203 (44) | 124/193 (64) |
| Former | 88/203 (43) | 36/193 (19) |
| Never | 23/203 (11) | 28/193 (15) |
| Unknown | 2/203 (1) | 5/193 (3) |
| Clinical presentation | ||
| Disease duration, median (IQR), yb | 6 (2-14) | 16 (10-20)d |
| Nail involvement, No. (%) | 65/203 (32) | 64/193 (33) |
| Concurrent psoriasis vulgaris, No. (%) | 66/203 (33) | 22/193 (11) |
| Concurrent psoriatic arthritis, No. (%) | 20/203 (10) | 17/193 (9) |
| Severity | ||
| PPPASI score, median (IQR)e | 8.2 (2.2-15.6) | NA |
| DLQI score, median (IQR)f,g | 10 (3.3-16) | NA |
| On systemic treatment, No. (%)h | 78/203 (38) | 34/193 (18) |
| PGA score, No. (%)i | NA | |
| Clear/mild (0-2) | 120/193 (62) | |
| Moderate/severe (3-4) | 73/193 (38) | |
| Comorbid disease, No. (%) | ||
| Asthma | 25/203 (12) | 5/93 (5)d |
| Depression | 31/203 (15) | 28/193 (15) |
| Diabetes | 26/203 (13) | 29/193 (15) |
| Hypertension | 41/203 (20) | 58/193 (30) |
| Autoimmune thyroid disease | 14/203 (7) | 25/193 (13) |
| Obesityj | 60/150 (40)k | 51/193 (26) |
Abbreviations: DLQI, Dermatology Life Quality Index; IQR, interquartile range; NA, not applicable; PGA, Physician Global Assessment; PPPASI, Palmoplantar Pustular Psoriasis Area Severity Index.
All study participants were of European descent.
Data not available for 11 UK cases and 1 Northern European case.
One patient had a family history of both psoriasis vulgaris and pustular psoriasis.
Information not available for the 100 patients recruited in Vienna, Austria.
PPPASI measures severity with scores from 0 (no sign of disease) to 72 (very severe disease).
Data not available for 8 UK cases.
DLQI measures quality of life with scores from 0 to 30; higher scores indicate greater impairment.
On systemic treatment at the time of recruitment or the preceding 4 weeks.
PGA measures severity as 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), and 4 (severe).
Body mass index greater than 30 (calculated as weight in kilograms divided by height in meters squared).
Data not available for 53 UK cases.