Differential Diagnosis

Superficial thrombophlebitis
Superficial vein thrombophlebitis is a common inflammatory-thrombotic process that may occur spontaneously or as a complication of medical or surgical interventions. Sterile thrombophlebitis limited to the superficial veins rarely is life threatening, but a thorough diagnostic evaluation is mandatory because many patients with superficial phlebitis also have occult deep vein thrombosis (DVT), which carries high rates of morbidity and mortality.
Patients with superficial thrombophlebitis often give a history of a gradual onset of localized tenderness, followed by the appearance of an area of erythema along the path of a superficial vein. A history of local trauma, prior similar episodes, varicose veins, prolonged travel, hormone use, tobacco use, family history of blood coagulopathies, or enforced stasis may be given. Asking about these risk factors for hypercoagulability should be done, but the absence of identifiable risk factors has no prognostic value.
• Traumatic thrombophlebitis: Ask about trauma, needlesticks, indwelling IV catheters, drug (eg, phenytoin) or hypertonic (10% calcium chloride) solution infusion and sclerotherapy.
• Thrombosed varicose veins: Ask about history of varicose veins


Varicose veins
Varicose veins and telangiectasia (spider veins) are the visible surface manifestations of an underlying problem with reverse venous flow, which is also termed venous insufficiency syndrome. Venous insufficiency syndromes describe venous blood deviating from a normal flow path and flow in a retrograde direction so that fluid accumulates, causing a "congested" leg.
Mild forms of venous insufficiency are merely uncomfortable, annoying, or cosmetically disfiguring, but severe venous disease can produce serious systemic consequences and can lead to loss of life or limb.
Most patients with venous insufficiency have subjective symptoms that may include pain, soreness, burning, aching, throbbing, cramping, muscle fatigue, and restless legs. Over time, chronic venous insufficiency leads to cutaneous and soft tissue breakdown that can be debilitating.


Cellulitis
The word cellulitis literally means inflammation of the cells. It generally indicates an acute spreading infection of the dermis and subcutaneous tissues resulting in pain, erythema, edema, and warmth.
Skin and subcutaneous tissues are involved when microorganisms, typically gram-positive bacteria, invade disrupted skin.

The skin disruption may be obvious, such as a laceration, fissure, or puncture wound. However, cellulitis frequently occurs in areas where no apparent injury exists. This is common in dry and irritated skin where microscopic breaks allow penetration of bacteria.

The infection triggers an inflammatory response that results in the clinically apparent pain, redness, warmth, and swelling.

Muscle Injury/Compartment Syndrome
Compartment syndrome (CS) is a condition in which the perfusion pressure falls below the tissue pressure in a closed anatomic space, with subsequent compromise of tissue circulation and function. Each muscle or muscle group is enclosed in a compartment bound by relatively rigid walls of bone and fascia. The compartments of the lower leg and the volar forearm are particularly prone to developing elevated compartment pressures.

As many as 45% of all cases of CS are caused by tibial fractures. Other causes include any long-bone fracture, vascular injury, compression in the setting of a crush injury, drug overdose, and a tight cast or dressing. Late manifestations of CS include the absence of a distal pulse, extremity paresis, and hypoesthesia. Compartment syndrome (CS) may be the result of either externally applied compressive forces or internally expanding forces. Fractures, vascular injuries, DVT, overexertion, fluid sequestration, or prolonged compression (as from a cast or other cause) may lead to CS. DVT rarely leads to CS, except in the most severe form of DVT, phlegmasia cerulea dolens.

Others:
Achilles tendonitis
Arterial insufficiency
Arthritis
Asymmetric peripheral edema secondary to CHF, liver disease, renal failure, or nephrotic syndrome
Cellulitis, lymphangitis
Extrinsic compression of iliac vein secondary to tumor, hematoma, or abscess
Hematoma
Lymphedema
Muscle or soft tissue injury
Neurogenic pain
Postphlebitic syndrome
Prolonged immobilization or limb paralysis
Ruptured Baker cyst
Stress fractures or other bony lesions
Superficial thrombophlebitis
Varicose veins