Clinical features
| | | | | | | |
Age at onset (years) | 32 | 35 | 48 | 46 | 39 | 70 | 66 |
Sex | M | F | F | M | F | F | F |
Weakness | | | | | | | |
Proximal > distal | + | + | + | + | + | + | + |
Arms + legs | + | + | + | + | + | + | + |
Maximum severity (% of normal strength) | 0% | 20% | 0% | 0% | 0% | 20% | 0% |
Time to maximum severity (months) | 5 | 12 | 3 | 8 | 4 | 2 | 2 |
Season of onset of weakness | Autumn | Autumn | Summer (August) | Autumn | Winter (January) | Autumn | Autumn |
Muscle pain | + | + | − | + | − | − | + |
Fatigue | + | + | + | + | + | − | − |
Dysphagia | − | + | − | − | − | + | + |
Skin rash | − | − | − | − | − | + | − |
Dyspnoea | + | − | − | − | − | − | + |
Palpitations | − | − | − | − | − | − | − |
Weight loss | + | − | − | + | − | − | + |
Steroid response | − | + | + | + | + | + | + |
| | | | | | | |
Laboratory data
| | | | | | | |
Creatine kinase (maximum) (IU/l) | 6204 | 3064 | 24 972 | 8940 | 7406 | 25 000 | 15 034 |
Aldolase (IU/l) | 55 | ND | ND | ND | 28.5 | 23 | 174 |
ESR (mm/h) | 42 | 19 | 38 | 12 | 40 | 34 | 1 |
Antinuclear antibody | − | − | − | − | − | 1:160 | − |
EMG | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act | Myopathic; sp act |