1. urticaria. Urticaria is a kind of skin disease caused by food, drugs or other factors, which will temporarily expand the small blood vessels of skin mucosa and increase the permeability, resulting in a large number of red papules on the body, accompanied by edema, itching and other symptoms. Patients can be treated with antihistamines, such as ebastine and mizolastine.
2. scabies. Scabies is an infectious skin disease caused by human scabies mites parasitic on the skin, which can suddenly cause a large number of red papules on the body, accompanied by severe itching at night. Patients can be treated with topical drugs such as sulfur ointment and salicylic acid ointment. If drug treatment fails, scabies can be treated by excision.
3. Contact dermatitis. Contact dermatitis is an inflammatory reaction caused by skin contact with allergens, which can lead to a large number of red papules on the body, accompanied by itching, burning pain and other symptoms. Patients need to stay away from allergens, and then use glucocorticoid drugs such as prednisone and dexamethasone for treatment.