Itchy hands with hard lumps may be due to hives, contact dermatitis, scabies and other diseases. 1. Urticaria: Urticaria may be caused by food allergies, infections, drugs, physical stimuli and other factors. Patients will have itchy skin, wind, and other symptoms, scratching the symptoms are more obvious, can be manifested as itchy hands with hard lumps. 2. Contact dermatitis: contact dermatitis may be caused by animals, plants, cosmetics, daily necessities and other factors. Patients will have localized itching, swelling and pain, papules, erythema, blisters and other symptoms, manifested as itchy hands and hard lumps. 3. Scabies: Scabies is a contact infectious skin disease caused by the scabies mite in the epidermis of the skin. Patients manifested as papules, blisters, itchy nodules, etc., patients will appear itchy hands with hard lumps. There are many causes of itchy hard lumps (such as nodular itchy rash, insect bite dermatitis, folliculitis), and it is recommended that patients go to a regular hospital to find out the cause of the disease.