Phimosis or Paraphimosis: This condition is common in pre-teen boys and can cause penile pain due to the inability to retract the foreskin or its retraction behind the glans penis, leading to swelling and discomfort.

Urinary Tract Infection (UTI): UTIs can cause dysuria, frequency, and penile pain, especially if the infection involves the urethra.
Balanitis: Inflammation of the glans penis, often due to poor hygiene or infection, which can cause pain, redness, and swelling.
Trauma: Accidental injury to the penis, such as a zip injury or direct blow, can cause pain and swelling.

Testicular Torsion: Although testicular torsion typically presents with testicular pain, it can sometimes radiate to the penis. This is a surgical emergency that requires immediate attention to preserve the testicle.
Epididymitis: Inflammation of the epididymis, which can cause severe pain that may radiate to the penis, and is often associated with UTIs or sexually transmitted infections (STIs) in sexually active males.
Penile Fracture: A rare but serious condition that occurs when the penis is erect and is subjected to a sudden, forceful bending, causing a tear in the tunica albuginea. It requires immediate medical attention.

Henoch-Schönlein Purpura (HSP): A systemic vasculitis that can cause penile pain and swelling, along with the characteristic purpuric rash, abdominal pain, and joint pain.
Behçet's Disease: A rare condition characterized by recurrent oral and genital ulcers, which can cause penile pain and swelling, along with other systemic symptoms.
Penile Cancer: Extremely rare in children, but any persistent or unexplained penile lesion or pain should be evaluated for malignancy.