Deep Vein Thrombosis (DVT): This condition is characterized by the formation of a blood clot in a deep vein, typically in the legs. Symptoms include swelling, warmth, and discoloration of the affected limb, which matches the description provided.

Cellulitis: A bacterial skin infection that can cause redness, swelling, and warmth in the affected area. The blotchy appearance of the calf could be indicative of cellulitis, especially if there's a history of trauma or infection.
Lymphedema: Swelling caused by impaired lymph drainage, which can lead to swelling and changes in skin texture. However, lymphedema typically presents with more chronic symptoms and may not fully account for the acute warmth and blotchiness.
Thrombophlebitis: Inflammation of veins due to a blood clot, which can cause swelling, warmth, and discoloration. This condition can present similarly to DVT but may have more superficial symptoms.

Septic Thrombophlebitis: A condition where a blood clot in a vein becomes infected, leading to severe infection and potentially life-threatening complications if not promptly treated.
Necrotizing Fasciitis: A rare but deadly infection of the tissue beneath the skin and surrounding muscles and organs. It requires immediate medical attention and can present with swelling, redness, and warmth, along with severe pain out of proportion to the visible symptoms.
Compartment Syndrome: Increased pressure within a muscle compartment, which can lead to muscle and nerve damage. Symptoms include severe pain, swelling, and warmth, and it is a medical emergency.

Erythema Nodosum: An inflammatory condition characterized by the formation of nodules under the skin, often on the shins. It can cause redness, swelling, and warmth but typically does not present with the significant swelling described.
Kawasaki Disease: A rare condition that mainly affects children, causing inflammation in the walls of medium-sized arteries throughout the body. It can present with fever, rash, swelling of the hands and feet, and other symptoms, but it's less likely given the specific focus on thighs and calves.
Blue Toe Syndrome: A condition caused by a small blood clot or other debris blocking the flow of blood to the toes, which can cause pain, swelling, and discoloration. However, it typically affects the toes rather than the thighs and calves.