What should I do if there is a small hard lump under the baby's penis?

Patient's question:

Basic Information: Male, 3 years old
Disease/Symptoms: Small hard lumps under the baby's penis
Condition Description: Please ask the expert, a 4-year-old baby has small hard lumps under the penis, about half a month, painless and itchy?

Doctor's answer:

According to your description, it is important to pay attention to the possibility of penile plaques. The main causes are related to infection and trauma. The main symptom is the proliferation of connective tissue in the penis. There is one or more hard plaques and cords on the dorsal side of the penis. When the penis is erect, it bends upward or to the left or right, and there is a slight sense of pain. If the bending is significant, it may affect sexual life.
Advice: It is recommended that you pay attention to hygiene and go to the hospital for examination to confirm the diagnosis. Follow the doctor's advice for treatment. Wish you good health!
Follow-up question: Do you need an ultrasound? It is recommended to consult your attending physician when going to the hospital for examination.