Phlegmasia cerulea dolens (PCD) (literally: painful blue inflammation), not to be confused with preceding phlegmasia alba dolens, is an uncommon severe form of lower extremity deep venous thrombosis (DVT) that obstructs blood outflow from a vein. Upper extremity PCD is less common, occurring in under 10% of all cases. PCD results from extensive thrombotic occlusion (blockage by a thrombus) of extremity veins, most commonly an "iliofemoral" DVT of the iliac vein and/or common femoral vein. It is a medical emergency requiring immediate evaluation and treatment. Symptoms and signs
Primary symptoms
It is characterized by progressive lower extremity edema distal to the thigh, tight shiny skin, cyanosis (inadequate blood oxygenation), petechiae or purpura, and sudden severe pain of the affected limb in proportion to the level of venous blockage. Patients often have difficulty walking. Blisters, bullae, paresthesias, and motor weakness may develop in severe cases, along with gangrene in ~50% of cases. Distal pulses are palpable early on but may diminish over time, and doppler signal can be usually heard throughout disease progression. The left limb is more commonly affected due to its vascular anatomy (the right internal iliac artery directly overlies the left iliac vein). Associated diseases
PCD is associated with an underlying malignancy in 20-40% of cases. There is a high risk of massive pulmonary embolism, even under anticoagulation.
An exostosis, also known as bone spur, is the formation of new bone on the surface of a bone. Exostoses can cause chronic pain ranging from mild to debilitatingly severe, depending on the shape, size, and location of the lesion. It is most commonly found in places like the ribs, where small bone growths form, but sometimes larger growths can grow on places like the ankles, knees, shoulders, elbows and hips. Very rarely are they on the skull. Exostoses are sometimes shaped like spurs, such as calcaneal spurs. Osteomyelitis, a bone infection, may leave the adjacent bone with exostosis formation. Charcot foot, the neuropathic breakdown of the feet seen primarily in diabetics, can also leave bone spurs that may then become symptomatic. They normally form on the bones of joints, and can grow upwards. For example, if an extra bone formed on the ankle, it might grow up to the shin. When used in the phrases "cartilaginous exostosis" or "osteocartilaginous exostosis", the term is considered synonymous with osteochondroma. Some sources consider the two terms to mean the same thing even without qualifiers, but this interpretation is not universal. Osteophytes
Osteophytes are bone spurs that develop on the margins of joints secondary to external stimuli such as osteoarthritis. However, these are not always distinguished from exostoses in any definite way. Fossil record
Evidence for exostosis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury.