The differences between erythema multiforme and eczema are etiology, clinical manifestation and treatment. 1. Etiology: Eczema is an allergic skin disease related to allergy, which is related to contact with some allergic substances, food, or genetic factors; whereas erythema multiforme can be caused by infections, medicines, visceral diseases, and physical factors. 2. Clinical manifestations: eczema can occur in any part of the body, can be localized or generalized, with oozing as the main symptom in the acute stage, accompanied by obvious itching, symmetrical and recurrent. Erythema multiforme will appear before the disease, such as joint pain, tiredness of limbs, fever and head pain, and then there will be a rash, which is polymorphic, more in number, mostly occurring at the end of the limbs, with typical target-shaped damages, and lymph node enlargement will also be seen in patients with severe diseases. 3. Treatment: Eczema can take antihistamines to stop itching, mild eczema can use topical medication, and severe eczema should also be treated with glucocorticoids, VC, calcium and so on. Erythema multiforme can be treated locally and systemically; erythema multiforme should be treated for the cause of the disease, and the infected ones should remove the infection, and the serious ones should use hormone treatment as appropriate. The above two diseases are common in dermatology, and it is recommended that patients should consult a doctor in time to get a clear diagnosis and follow the doctor’s instructions for treatment.