The following symptoms and complaints may indicate myalgia (muscle pain):
Muscle pain may be local (localized) or diffuse (generalized). The pain may occur as continuous pain or intermittently. In most myopathies (muscle diseases), the pain often occurs intermittently, although it is a chronic disease!
Warning signs (red flags)
- Medical history: Lipid-lowering agents:
- Cholesterol absorption inhibitor – ezetimibe.
- Fibrinic acid derivatives – bezafibrate, fenofibrate, gemfibrozil
- HMG-CoA reductase inhibitors (statins) – Statin-associated muscle pain (SAMS): Atorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin; more commonly rhabdomyolysis (dissolution of striated muscle fibers/skeletal muscle as well as cardiac muscle) in combination with fibrates, ciclosporin (cyclosporin A), macrolides, or azole antifungals → think of: Coenzyme Q10 deficiency
- Fever → think of: viral infection
- Violent muscle pain, symmetrically occurring, mainly affected:
- Shoulder girdle
- Pelvis
Tenderness, stiffness of muscles, especially long lasting morning stiffness (> 45 min), weakness of muscles → think of: Polymyalgia rheumatica (associated with giant cell arteritis in over 50% of cases).
- Progressive (increasing) muscle weakness → think of: Poliomyelitis (polio).
- Other differential diagnoses of muscle weakness and myalgias include:
- Myasthenia gravis (load-dependent muscle weakness, typically eyelid-lifting weakness).
- Muscular dystrophies (muscle wasting; positive family history, onset in childhood or young adulthood).
- Parasitic muscle diseases such as trichinellosis (eosinophilia in the blood count; muscle weakness in the convalescence phase, possibly persistent for years).
