A periorbital heliotrope rash is often seen in dermatomyositis. It is bilateral, symmetric, purpuric, and macular, and erupts over the eyelids and surrounding periorbital area. Malar rash (often called a "butterfly rash") is seen in patients with systemic lupus erythematosus (SLE). Dermatitis herpetiformis is a rash on the elbows and knees generally seen with gluten allergy (celiac disease). Perioral dermatitis is an iatrogenic condition often associated with prolonged use of topical steroid creams. 

Polymyositis is characterized by symmetric proximal muscle weakness in the upper and lower extremities, often without the presence of distal muscle weakness. The first sign is often weakness in the thighs while walking, the inability to rise from a seated position without assistance, or the inability to raise the arms above the head. 

Dermatomyositis generally includes a characteristic periorbital rash. Weakness is expressed in the neck, arms, and legs. Guillain-Barre syndrome is an ascending paralysis: symptoms start in the hands and feet, then spread proximally as it progresses. Muscular weakness in myasthenia gravis is often especially expressed in muscles of the face and head, especially those that control eye and eyelid movement, facial expression, chewing, swallowing, and speaking.

Paget's disease of bone is a condition characterized by high bone turnover due to accelerated osteoclast and osteoblast activity. This results in increased calcification of bones, especially prominent in the skull, pelvis, femur, and tibia. 

Osteogenesis imperfecta is an issue with collagen formation that causes fragile bones and multiple fractures. Multiple myeloma is a malignancy of plasma calls, and giant cell tumors are rare tumors that generally originate from the epiphysis of long bones (with no effect on bone deposition).

Paget's disease of the bone generally presents in after the age of 55, and is very rare in younger individuals. The prevalence in individuals over 55 is as high as 3%.

Osteoid osteoma is a benign, bone-forming tumor characterized by a small area of neoplastic growth surrounded by an area of mature, reactive bone.

Fibrosarcoma, osteosarcoma, and Ewing's sarcoma are all malignancies. 

Osteosarcoma is the most common primary malignancy of bone, excluding hematopoietic malignancies, making up approximately 20% of all primary bone cancers. 

Fibrosarcoma and Ewing's sarcoma are relatively rare conditions, and osteoid osteomas are is non-malignant.

Roughly 75% of osteosarcomas occur in the distal femur or around the knee. The next most common site is the upper arm. Spinal or pelvic involvement are rare. 

The majority of cases of osteosarcoma are in children and adolescents between the age of 10 and 25. It's the most common type of bone cancer in children and young adults, and the third most common cancer in teens.

Dystonia is a condition of sustained muscle contractions causing abnormal posture, twisting, restricted movement, and pain. Torticollis is a form of dystonia specific to the muscles of the neck. Ballismus is a condition of rapid, violent involuntary motions. Geniospasm is specific to the mentalis muscle, causing involuntary movements of the jaw.

Elevation of the limb above the heart may slow arterial perfusion and raise venous pressure, and worsen circulation. Ice may cause vasoconstriction and further lead to circulation compromise. Both of these interventions would not be appropriate for compartment syndrome. 

Know the six P's of compartment syndrome: pallor, pain on passive movement, paresthesia, paralysis, pulses, pressure: all of these may be present in compartment syndrome. Pulselessness is an ominous sign of impending permanent damage, the physician should be notified. Muscle damage can lead to myoglobinemia of the blood thereby damaging the kidneys leading to rhabdomyolysis and dark urine. A tight bandage could further increase the pressure in the compartment and should be loosened if this is so.