Cellulitis: This is a common cause of hand edema, characterized by bacterial infection of the skin and soft tissues. It presents with redness, warmth, swelling, and sometimes pus.

Insect Bite or Sting: Allergic reactions to insect bites or stings can cause localized edema, redness, and itching.
Contact Dermatitis: Irritant or allergic contact dermatitis can lead to hand edema, especially if the individual has been exposed to new substances or has a history of allergies.
Lymphedema: Although less common in the hand, lymphedema can occur due to obstruction of lymphatic vessels or nodes, often secondary to surgery, infection, or trauma.

Compartment Syndrome: A medical emergency where increased pressure within a confined space in the hand can lead to nerve and muscle damage. It requires prompt recognition and treatment.
Deep Vein Thrombosis (DVT): Although more common in the legs, DVT can occur in the upper extremities, including the hand, and can lead to pulmonary embolism if not treated.
Necrotizing Fasciitis: A severe infection that destroys tissue under the skin, requiring immediate medical attention to prevent severe morbidity and mortality.

Sarcoidosis: A systemic disease that can cause edema and swelling in various parts of the body, including the hands, due to granulomatous inflammation.
Angioedema: A rare condition characterized by rapid swelling of the skin and mucous membranes, which can be hereditary or acquired.
Klippel-Trenaunay Syndrome: A congenital condition that affects blood and lymph vessels, leading to edema, varicose veins, and other vascular anomalies.