Erythema on the penis may be caused by diseases such as glansitis, contact dermatitis and syphilis.
1. Glansitis: the etiology may be related to infection, trauma and other factors. Patients will have localized edema, erythema, erosion and other symptoms.
2. Contact dermatitis: it is mainly related to skin contact with exogenous substances that irritate the skin or cause allergic reactions. Patients will appear local erythema, papules, swelling and other symptoms.
3. Syphilis: the cause of the disease is mainly related to syphilis spirochete infection, sexually active, promiscuous and other factors can also induce the disease. Stage II syphilis can be manifested as erythema and scaling of the external genitalia, and is more common in men in the penis, glans and other parts of the body.
There are many causes of erythema on the penis, and patients are advised to go to the hospital to find out the cause of the disease.