One hand swollen and itchy: possible reasons

A new soap, detergent, glove, plant, metal, or chemical can irritate the skin or trigger contact allergy. An insect bite may create a local itchy bump and surrounding puffiness. Hives can move or appear in more than one place. Infection is more concerning when swelling is hot, painful, increasingly red, or accompanied by fever; itch may occur around a wound but is not a reliable way to rule infection out. A hand that is swollen without a visible skin trigger can still need assessment for injury, joint inflammation, or circulation changes.

Rinse away a suspected irritant, remove rings and watches, and avoid the suspected product until the skin settles. Apply a cool, damp cloth and keep the hand raised. Do not scratch, break blisters, or use a new cream on broken skin without advice. Note what touched the hand and when symptoms began. A pharmacist or clinician can advise whether an antihistamine or topical treatment is suitable, taking pregnancy, age, and other medicines into account.

Call emergency services for swelling of the lips, tongue, or throat, trouble breathing, wheezing, dizziness, or collapse. Seek urgent care for rapid hand swelling, severe pain, numbness, blue or pale colour, marked heat, spreading redness, pus, or fever. Arrange medical review if the itch persists, the skin cracks, or episodes recur without a clear trigger.

Could a product, bite, medicine, or infection explain this reaction? Should I stop or replace anything I am using? Which symptoms mean I need emergency help?