Benzylpenicillin, the dosage form used is usually an injection and is a prescription drug. The use of benzylpenicillin red spots, consider and the use of the drug after the adverse reaction, allergic reaction related. Benzylpenicillin is a penicillin drug that is sensitive to beta-lactamase, and it is an injectable western drug, in which the main ingredient is benzylpenicillin. Benzylpenicillin for injection, with the character of white crystalline powder, is mainly used to prevent the recurrence of rheumatic fever and control the prevalence of streptococcal infections. After the use of the drug, individual patients may have allergic reactions, the skin may appear urticaria-like changes, mainly in the form of rashes and other allergic reactions are common, the skin may appear red dots. In case of allergy to the components inside the drug, erythema, acne, papules may appear on the skin, accompanied by a pronounced itching sensation. Individuals may have asthma attacks, interstitial nephritis, leukopenia, serum sickness, and in severe cases, anaphylactic shock after using the drug. Prompt resuscitation is recommended to keep the airway open. Pregnant women, lactation, infants and young children use the drug strictly in accordance with medical advice. It is forbidden to use the drug when its properties have changed, and if you are using other drugs, you need to inform your doctor in advance. It is forbidden to be allergic to the ingredients inside the drug, and it is forbidden to have a history of allergy to penicillins. Application of the product needs to be freshly prepared, with asthma, eczema, chilblain fever, urticaria and other allergic diseases patients with caution.