Table 3.
Patient demographics, predisposing factors and initial presentation (n = 85)
| Age at disease onset [median (range)], years | 41 (16–75) |
| Sex (male), n (%) | 46 (54.1) |
| Ethnicity, n (%) | |
| White | 84 (98.8) |
| Black | 0 (0.0) |
| Asian | 1 (1.2) |
| Season at disease onset, n (%) | |
| Summer | 13 (15.3) |
| Autumn | 19 (22.4) |
| Winter | 21 (24.7) |
| Spring | 27 (31.8) |
| Not recorded | 5 (5.9) |
| Predisposing factor, n (%) | |
| Upper respiratory tract infection | 39 (45.9) |
| Alcohol | 9 (10.6) |
| Drug | 5 (5.9) |
| Physical stress | 5 (5.9) |
| Immunization | 2 (2.4) |
| Psychological stress | 2 (2.4) |
| Malignancy | 2 (2.4) |
| No predisposing factor identified | 33 (38.8) |
| Clinical presentation, n (%) | |
| Palpable purpura | 85 (100) |
| Ulcerative rash | 10 (11.8) |
| Joint involvement | 59 (69.4) |
| Gastrointestinal involvement | 40 (47.1) |
| Renal involvement | 66 (77.6) |
| eGFR <60 mL/min/1.73 m2 | 11 (12.9) |
| AKI Stage 1 | 7 (8.2) |
| AKI Stage 2 | 1 (1.2) |
| AKI Stage 3 | 3 (3.5) |
| Proteinuria | 51 (60.0) |
| Nephrotic-range proteinuria | 3 (3.5) |
| Haematuria | 57 (67.1) |
| Macroscopic haematuria | 8 (9.4) |
| Hypertension | 35 (41.2) |
| Not recorded | 9 (10.6) |
| Ear, nose and throat involvement | 7 (8.2) |
| Pulmonary involvement | 6 (7.1) |
| Oral mucosal ulceration | 2 (2.4) |
| Testicular involvement | 1 (1.2) |
| Ocular involvement | 1 (1.2) |
| Constitutional symptoms | 42 (49.4) |
| Laboratory examinations, n (%) | |
| IgA >4 g/L | 27 (31.8) |
| Not recorded | 7 (9.4) |
| CRP >5 mg/L | 43 (50.6) |
| Not recorded | 6 (7.1) |
| ESR >20 mm/h | 27 (31.8) |
| Not recorded | 9 (10.6) |