Table 4. Classification of etiology by age groups.
| Age Groups (years) | Total | |||||||||
| 0–20 | 21–40 | 41–60 | >60 | |||||||
| No. of patients (n) | 11 | 23 | 24 | 8 | 66 | |||||
| Idiopathic (n, %) * | 7 | (63.6) | 11 | (47.8) | 15 | (62.5) | 6 | (75.0) | 39 | (59.1) |
| Infective (n, %) * | 2 | (18.2) | 5 | (21.7) | 6 | (25.0) | 1 | (12.5) | 14 | (21.2) |
| TB | 2 | (18.2) | 4 | (17.4) | 4 | (16.7) | 0 | (0.0) | 10 | (15.2) |
| Syphilis | 0 | (0.0) | 1 | (4.3) | 0 | (0.0) | 1 | (12.5) | 2 | (3.0) |
| HSV† | 0 | (0.0) | 0 | (0.0) | 1 | (4.2) | 0 | (0.0) | 1 | (1.5) |
| HIV | 0 | (0.0) | 0 | (0.0) | 1 | (4.2) | 0 | (0.0) | 1 | (1.5) |
| Immune-mediated (n, %) * | 2 | (18.2) | 7 | (30.4) | 2 | (8.3) | 0 | (0.0) | 11 | (16.7) |
| Sarcoidosis | 0 | (0.0) | 2 | (8.7) | 2 | (8.3) | 0 | (0.0) | 4 | (6.1) |
| MS | 0 | (0.0) | 2 | (8.7) | 0 | (0.0) | 0 | (0.0) | 2 | (3.0) |
| Behcet | 0 | (0.0) | 2 | (8.7) | 0 | (0.0) | 0 | (0.0) | 2 | (3.0) |
| AS | 1 | (9.1) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (1.5) |
| Psoriasis‡ | 0 | (0.0) | 1 | (4.3) | 0 | (0.0) | 0 | (0.0) | 1 | (1.5) |
| JIA | 1 | (9.1) | 0 | (0.0) | 0 | (0.0) | 0 | (0.0) | 1 | (1.5) |
| Masquerade (n, %) * | 0 | (0.0) | 0 | (0.0) | 1 | (4.2) | 1 | (12.5) | 2 | (3.0) |
*expressed as percentage of patients within age group.
†
HSV was diagnosed with a positive polymerase chain reaction test.
‡
Psoriasis was diagnosed based on a clinical diagnosis of IU and dermatologic manifestations diagnosed as psoriasis by a dermatologist.
Abbreviations: TB, tuberculosis; HSV, Herpes simplex virus; HIV, human immunodeficiency virus; MS, multiple sclerosis; AS, ankylosing spondylitis; JIA, juvenile idiopathic arthritis.