Osteomyelitis
Other etiologies of arthritis
Trauma
Vaso-occlusive pain crisis
Bony infarction<unk> 
Avascular necrosis of femoral head
Acute chest syndrome
Asthma
Pulmonary hypertension
Gallbladder disease
Acute hepatic sequestration
Infection
Meningitis
Pneumonia
Septic joint
Osteomyelitis
Parvovirus B19
Splenic sequestration
CVA
Cerebral aneurysm and ICH
Priapism
Papillary necrosis
Meningitis
Pneumonia
Septic joint
Osteomyelitis
Dactylitis
Osteomyelitis
Hand cellulitis
Other etiologies of arthritis
Tendonitis
Trauma
Tinea pedis
Vaso-occlusive pain crisis