Table 1.
Summary of demographic data of patients with jIIM.
| Patients with jIIM | |
|---|---|
| Number of patients | 15 |
| Age at biopsy (median) | 8 years |
| range | (3–17 years) |
| female | 11 (73%) |
| Skeletal muscle symptoms | 14 (93%) |
| Myalgia | 11 (73%) |
| Exercise induced myalgia | 6 (40%) |
| Proximal weakness | 14 (93%) |
| Skin symptoms | 15/15 (100%) |
| Dry skin | 6 (40%) |
| Exanthema | 3 (20%) |
| Erythema | 4 (27%) |
| Butterfly rash | 5 (33%) |
| Redness, livid coloration | 8 (53%) |
| Raynaud’s phenomenon | 1 (7%) |
| Gottron’s papules | 8 (53%) |
| Nail fold changes | 1 (7%) |
| Calcinosis | 4 (27%) |
| Accompanying symptoms | 15/15 (100%) |
| Fever | 3 (20%) |
| Difficulty swallowing | 1 (7%) |
| Morning stiffness | 1 (7%) |
| Arthritis | 1 (7%) |
| Weight gain | 2 (13%) |
| Weight loss | 1 (7%) |
| Night sweat | 1 (7%) |
| Oedema | 3 (20%) |
| Lymphadenopathy | 1 (7%) |
| Fatigue, concentration difficulties | 7 (47%) |
| Loss of appetite/rejection to drink | 1 (7%) |
| Sadness/mood slump/mood swings | 5 (33%) |
| Social withdrawal | 3 (20%) |
| Extramuscular symptoms | 5/15 (33%) |
| Pulmonary restriction | 2 (13%) |
| Pneumonia | 1 (7%) |
| Cardial involvement | 4 (27%) |
| Comorbidities | 5/15 (33%) |
| Cystic fibrosis | 1 (7%) |
| Factor-V-Leiden mutation | 1 (7%) |
| Hypothyroidism | 1 (7%) |
| Steatosis hepatis | 1 (7%) |
| HLA-B27 enthesitis | 1 (7%) |
| Laboratory results | 15/15 (100%) |
| Creatine kinase (CK) ↑ | 14 (93%) |
| Lactatdehydrogenase (LDH) ↑ | 11 (73%) |
| GOT ↑ | 11 (73%) |
| GPT ↑ | 7 (47%) |
| Serum antibodies | |
| Myositis-specific-antibodies (MSA) | 6/12 (50%) |
| Anti-NXP-2 | 2 (17%) |
| Anti-PL-7 | 2 (17%) |
| Anti–Jo-1 | 2 (17%) |
| Myositis-associated-antibodies (MAA) | 2/12 (17%) |
| Anti-Ro52 | 1 (8%) |
| PM75 | 1 (8%) |
| Antinuclear antibodies (ANA) | 9/13 (69%) |
| Systemic Lupus erythematodes (SLE) | |
| Anti-double-stranded-DNA-antibodies (Anti-dsDNA) | 1 (8%) |
| Smith-Antibodies (Anti-Sm/Sm-AK) | 1 (8%) |
| Anti RNP/Sm-AK | 2 (17%) |
| MRI skeletal muscle | 11/15 (73%) |
| Normal | 2 (18%) |
| Oedema | 6 (54%) |
| Enhancement of contrast medium/signal alterations | 4 (36%) |
| Compatible with myositis | 8 (73%) |
| Musculoskeletal Ultrasound | 9/15 (60%) |
| Oedema | 3 (33%) |
| Enhancement of echogenicity/signal alterations | 6 (67%) |
| Compatible with myositis | 6 (67%) |
| Electromyography (EMG) | 11/15 (73%) |
| Myopathic, compatible with myositis | 8 (72%) |
| Unspecific sign | 3 (27%) |